Science.gov

Sample records for limited water annual

  1. [Plant growth with limited water]. [Annual report, December 15, 1992--December 14, 1993

    SciTech Connect

    Not Available

    1993-12-01

    We used a soybean seedling system to explore the mechanism of growth limitation by water deficiency (low {Psi}{sub W}). Our prior work had show that (low {Psi}{sub W} inhibited plant growth initially because of a physical limitation to water uptake that appeared to result from a decrease in the {Psi}{sub W} gradient feeding water to the enlarging cells. The gradient was shown to originate from cell wall yielding and was altered primarily at the vascular tissue. In the present grant, we reported the detailed shape of the gradient. We also found that growth could mobilize water from mature tissues in the complete absence of external water using the gradient in {Psi}{sub W}. Growth was maintained by this mobilization. After growth has been inhibited a few hours, metabolic changes occur and a 28kD protein accumulates in the wall fraction of the growth-affected cells. In the present grant, we showed that the mRNA for the protein accumulated in a tissue-specific manner similar to that of the protein, and the accumulation was correlated with the growth response. Other investigators working independently with an acid phosphatase found a deduced amino acid sequence similar to that for the 28kD protein we had published. Biochemical tests showed that the 28kD protein and a related 3lkD protein expressed acid phosphatase activity. We found that the acid phosphatase Of the 28kD protein was in the cell walls of intact plants (in addition to being in the cytoplasm). Current work focuses on the role of this protein. Efforts were made to reverse the growth inhibition at low {Phi}{sub W} by treating growing tissues with low pH buffer, but the protons apparently failed to penetrate the cuticle.

  2. The effect of limited availability of N or water on C allocation to fine roots and annual fine root turnover in Alnus incana and Salix viminalis.

    PubMed

    Rytter, Rose-Marie

    2013-09-01

    The effect of limited nitrogen (N) or water availability on fine root growth and turnover was examined in two deciduous species, Alnus incana L. and Salix viminalis L., grown under three different regimes: (i) supply of N and water in amounts which would not hamper growth, (ii) limited N supply and (iii) limited water supply. Plants were grown outdoors during three seasons in covered and buried lysimeters placed in a stand structure and filled with quartz sand. Computer-controlled irrigation and fertilization were supplied through drip tubes. Production and turnover of fine roots were estimated by combining minirhizotron observations and core sampling, or by sequential core sampling. Annual turnover rates of fine roots <1 mm (5-6 year(-1)) and 1-2 mm (0.9-2.8 year(-1)) were not affected by changes in N or water availability. Fine root production (<1 mm) differed between Alnus and Salix, and between treatments in Salix; i.e., absolute length and biomass production increased in the order: water limited < unlimited < N limited. Few treatment effects were detected for fine roots 1-2 mm. Proportionally more C was allocated to fine roots (≤2 mm) in N or water-limited Salix; 2.7 and 2.3 times the allocation to fine roots in the unlimited regime, respectively. Estimated input to soil organic carbon increased by ca. 20% at N limitation in Salix. However, future studies on fine root decomposition under various environmental conditions are required. Fine root growth responses to N or water limitation were less pronounced in Alnus, thus indicating species differences caused by N-fixing capacity and slower initial growth in Alnus, or higher fine root plasticity in Salix. A similar seasonal growth pattern across species and treatments suggested the influence of outer stimuli, such as temperature and light.

  3. USGS Annual Water Data Reports

    SciTech Connect

    2012-04-01

    Water resources data are published annually for use by engineers, scientists, managers, educators, and the general public. These archival products supplement direct access to current and historical water data provided by the National Water Information System (NWIS). Beginning with Water Year 2006, annual water data reports are available as individual electronic Site Data Sheets for the entire Nation for retrieval, download, and localized printing on demand. National distribution includes tabular and map interfaces for search, query, display and download of data. Data provided include extreme and mean discharge rates.

  4. Drinking Water Program 1992 annual report

    SciTech Connect

    Andersen, B.D.; Peterson-Wright, L.J.

    1993-08-01

    EG&G Idaho, Inc., initiated a monitoring program for drinking water in 1988 for the US Department of Energy at the Idaho National Engineering Laboratory. EG&G Idaho structured this monitoring program to ensure that they exceeded the minimum regulatory requirements for monitoring drinking water. This program involves tracking the bacteriological, chemical, and radiological parameters that are required for a {open_quotes}community water system{close_quotes} (maximum requirements). This annual report describes the drinking water monitoring activities conducted at the 17 EG&G Idaho operated production wells and 11 distribution systems. It also contains all of the drinking water parameters that were detected and the regulatory limits that were exceeded during 1992. In addition, ground water quality is discussed as it relates to contaminants identified at the wellhead for EG&G Idaho production wells.

  5. 20 CFR 404.1047 - Annual wage limitation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....1047 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY... wage limitation. Payments made by an employer to you as an employee in a calendar year that are more than the annual wage limitation are not wages. The annual wage limitation is: Calendar year...

  6. 5 CFR 550.106 - Annual maximum earnings limitation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... of Personnel Management on its own motion, determines that an emergency exists, the agency must pay... pay under this annual limitation becomes effective on the first day of the pay period in which such... premium pay under this annual limitation becomes effective on the first day of the pay period designated...

  7. 39 CFR 3010.21 - Calculation of annual limitation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Calculation of annual limitation. 3010.21 Section 3010.21 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL REGULATION OF RATES FOR MARKET DOMINANT PRODUCTS Rules for Applying the Price Cap § 3010.21 Calculation of annual limitation. (a) The...

  8. Modeling Limited Foresight in Water Management Systems

    NASA Astrophysics Data System (ADS)

    Howitt, R.

    2005-12-01

    The inability to forecast future water supplies means that their management inevitably occurs under situations of limited foresight. Three modeling problems arise, first what type of objective function is a manager with limited foresight optimizing? Second how can we measure these objectives? Third can objective functions that incorporate uncertainty be integrated within the structure of optimizing water management models? The paper reviews the concepts of relative risk aversion and intertemporal substitution that underlie stochastic dynamic preference functions. Some initial results from the estimation of such functions for four different dam operations in northern California are presented and discussed. It appears that the path of previous water decisions and states influences the decision-makers willingness to trade off water supplies between periods. A compromise modeling approach that incorporates carry-over value functions under limited foresight within a broader net work optimal water management model is developed. The approach uses annual carry-over value functions derived from small dimension stochastic dynamic programs embedded within a larger dimension water allocation network. The disaggregation of the carry-over value functions to the broader network is extended using the space rule concept. Initial results suggest that the solution of such annual nonlinear network optimizations is comparable to, or faster than, the solution of linear network problems over long time series.

  9. 20 CFR 404.1047 - Annual wage limitation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Annual wage limitation. 404.1047 Section 404.1047 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Employment, Wages, Self-Employment, and Self-Employment Income Wages § 404.1047 Annual...

  10. 20 CFR 404.1047 - Annual wage limitation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Annual wage limitation. 404.1047 Section 404.1047 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Employment, Wages, Self-Employment, and Self-Employment Income Wages § 404.1047 Annual...

  11. 20 CFR 404.1047 - Annual wage limitation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Annual wage limitation. 404.1047 Section 404.1047 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Employment, Wages, Self-Employment, and Self-Employment Income Wages § 404.1047 Annual...

  12. 20 CFR 404.1047 - Annual wage limitation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Annual wage limitation. 404.1047 Section 404.1047 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Employment, Wages, Self-Employment, and Self-Employment Income Wages § 404.1047 Annual...

  13. 50 CFR 622.496 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Annual catch limits (ACLs), annual catch.... Virgin Islands § 622.496 Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). See § 622.12 for applicable ACLs and AMs....

  14. 50 CFR 622.457 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Annual catch limits (ACLs), annual catch.... Virgin Islands § 622.457 Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). See § 622.12 for applicable ACLs and AMs....

  15. 50 CFR 622.439 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Annual catch limits (ACLs), annual catch.... Virgin Islands § 622.439 Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). See § 622.12 for applicable ACLs and AMs....

  16. 50 CFR 622.439 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Annual catch limits (ACLs), annual catch.... Virgin Islands § 622.439 Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). See § 622.12 for applicable ACLs and AMs....

  17. 50 CFR 622.58 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). 622.58 Section 622.58 Wildlife and Fisheries FISHERY... Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). (a) Royal...

  18. 50 CFR 622.457 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Annual catch limits (ACLs), annual catch.... Virgin Islands § 622.457 Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). See § 622.12 for applicable ACLs and AMs....

  19. 50 CFR 622.496 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Annual catch limits (ACLs), annual catch.... Virgin Islands § 622.496 Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). See § 622.12 for applicable ACLs and AMs....

  20. 50 CFR 622.58 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). 622.58 Section 622.58 Wildlife and Fisheries FISHERY... Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs). (a) Royal...

  1. (Plant growth with limited water)

    SciTech Connect

    Not Available

    1991-01-01

    The work supported by DOE in the last year built on our earlier findings that stem growth in soybean subjected to limited water is inhibited first by a physical limitation followed in a few hours by metabolic changes that reduce the extensibility of the cell walls. With time, there is modest recovery in extensibility and a 28kD protein accumulates in the walls of the growth-affected cells. A 31kD protein that was 80% similar in amino acid sequence also was present but did not accumulate in the walls of the stem cells. Explorations of the mRNA for these proteins showed that the mRNA for the 28kD protein increased in the shoot in response to water deprivation but the mRNA for the 31kD protein did not accumulate. In contrast, the roots continued to grow and the mRNA for the 31kD protein accumulated but the mRNA for the 28kD protein was undetectable. We also explored how growth occurs in the absence of an external water supply. We found that, under these conditions, internal water is mobilized from surrounding nongrowing or slowly growing tissues and is used by rapidly growing cells. We showed that a low water potential is normally present in the enlarging tissues and is the likely force that extracts water from the surrounding tissues. We found that it involved a gradient in water potential that extended from the xylem to the outlying cells in the enlarging region and was not observed in the slowly growing basal tissue of the stems of the same plant. The gradient was measured directly with single cell determinations of turgor and osmotic potential in intact plants. The gradient may explain instances of growth inhibition with limited water when there is no change in the turgor of the enlarging cells. 17 refs.

  2. 26 CFR 1.401(a)(17)-1 - Limitation on annual compensation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... § 1.401(a)(17)-1 Limitation on annual compensation. (a) Compensation limit requirement—(1) In general... an annual compensation limit for each employee under a qualified plan. This limit applies to a... annual compensation limit. Second, the amount of an employee's annual compensation that may be taken into...

  3. 26 CFR 1.401(a)(17)-1 - Limitation on annual compensation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... § 1.401(a)(17)-1 Limitation on annual compensation. (a) Compensation limit requirement—(1) In general... an annual compensation limit for each employee under a qualified plan. This limit applies to a... annual compensation limit. Second, the amount of an employee's annual compensation that may be taken into...

  4. 30 CFR 57.5038 - Annual exposure limits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Annual exposure limits. 57.5038 Section 57.5038 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Air Quality, Radiation...

  5. 45 CFR 147.126 - No lifetime or annual limits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 1 2013-10-01 2013-10-01 false No lifetime or annual limits. 147.126 Section 147... to 2014—(1) In general. With respect to plan years (in the individual market, policy years) beginning prior to January 1, 2014, a group health plan, or a health insurance issuer offering group or individual...

  6. 30 CFR 57.5038 - Annual exposure limits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Annual exposure limits. 57.5038 Section 57.5038 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Air Quality, Radiation...

  7. 30 CFR 57.5038 - Annual exposure limits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Annual exposure limits. 57.5038 Section 57.5038 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Air Quality, Radiation...

  8. New Stochastic Annual Limits on Intake for Selected Radionuclides

    SciTech Connect

    Carbaugh, Eugene H.

    2009-08-24

    Annual limits on intake (ALI) have historically been tabulated by the International Commission on Radiological Protection (e.g., ICRP 1979, 1961) and also by the Environmental Protection Agency (EPA 1988). These compilations have been rendered obsolete by more recent ICRP dosimetry methods, and, rather than provide new ALIs, the ICRP has opted instead to provide committed dose coefficients from which an ALI can be determined by a user for a specific set of conditions. The U.S. Department of Energy historically has referenced compilations of ALIs and has defined their method of calculation in its radiation protection regulation (10 CFDR 835), but has never provided a specific compilation. Under June 2007 amendments to 10 CFR 835, ALIs can be calculated by dividing an appropriate dose limit, either 5-rem (0.05 Sv) effective dose or 50 rem (0.5 Sv) equivalent dose to an individual organ or tissue, by an appropriate committed dose coefficient. When based on effective dose, the ALI is often referred to as a stochastic annual limit on intake (SALI), and when based on the individual organ or tissue equivalent limit, it has often been called a deterministic annual limit on intake (DALI).

  9. (Plant growth with limited water)

    SciTech Connect

    Not Available

    1992-01-01

    When water is in short supply, soybean stem growth is inhibited by a physical limitation followed in a few hours by metabolic changes that reduce the extensibility of the cell walls. The extensibility then becomes the main limitation. With time, there is a modest recovery in extensibility along with an accumulation of a 28kD protein in the walls of the growth-affected cells. A 3lkD protein that was 80% similar in amino acid sequence also was present but did not accumulate in the walls of the stem cells. In the stem, growth was inhibited and the mRNA for the 28kD protein increased in response to water deprivation but the mRNA for the 3 1 kD protein did not. The roots continued to grow and the mRNA for the 28kD protein did not accumulate but the mRNA for the 3lkD protein did. Thus, there was a tissuespecific response of gene expression that correlated with the contrasting growth response to low water potential in the same seedlings. Further work using immunogold labeling, fluorescence labeling, and western blotting gave evidence that the 28kD protein is located in the cell wall as well as several compartments in the cytoplasm. Preliminary experiments indicate that the 28kD protein is a phosphatase.

  10. 76 FR 23962 - Fisheries Off West Coast States; Highly Migratory Species Fisheries; Annual Catch Limits and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-29

    ... States; Highly Migratory Species Fisheries; Annual Catch Limits and Accountability Measures AGENCY... annual catch limits (ACLs) and accountability measures (AMs). This proposed rule to implement Amendment 2... have any direct or indirect socioeconomic impacts, because harvest limits and management measures...

  11. 26 CFR 1.401(a)(17)-1 - Limitation on annual compensation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...(a)(17)-1 Limitation on annual compensation. (a) Compensation limit requirement—(1) In general. In... annual compensation limit for each employee under a qualified plan. This limit applies to a qualified... compensation limit. Second, the amount of an employee's annual compensation that may be taken into account in...

  12. 50 CFR 648.53 - Acceptable biological catch (ABC), annual catch limits (ACL), annual catch targets (ACT), DAS...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... catch limits (ACL), annual catch targets (ACT), DAS allocations, and individual fishing quotas (IFQ... limits (ACL), annual catch targets (ACT), DAS allocations, and individual fishing quotas (IFQ). (a... limited access scallop fishery shall be allocated 94.5 percent of the ACL specified in paragraph (a)(1)...

  13. Climate, soil water storage, and the average annual water balance

    USGS Publications Warehouse

    Milly, P.C.D.

    1994-01-01

    This paper describes the development and testing of the hypothesis that the long-term water balance is determined only by the local interaction of fluctuating water supply (precipitation) and demand (potential evapotranspiration), mediated by water storage in the soil. Adoption of this hypothesis, together with idealized representations of relevant input variabilities in time and space, yields a simple model of the water balance of a finite area having a uniform climate. The partitioning of average annual precipitation into evapotranspiration and runoff depends on seven dimensionless numbers: the ratio of average annual potential evapotranspiration to average annual precipitation (index of dryness); the ratio of the spatial average plant-available water-holding capacity of the soil to the annual average precipitation amount; the mean number of precipitation events per year; the shape parameter of the gamma distribution describing spatial variability of storage capacity; and simple measures of the seasonality of mean precipitation intensity, storm arrival rate, and potential evapotranspiration. The hypothesis is tested in an application of the model to the United States east of the Rocky Mountains, with no calibration. Study area averages of runoff and evapotranspiration, based on observations, are 263 mm and 728 mm, respectively; the model yields corresponding estimates of 250 mm and 741 mm, respectively, and explains 88% of the geographical variance of observed runoff within the study region. The differences between modeled and observed runoff can be explained by uncertainties in the model inputs and in the observed runoff. In the humid (index of dryness <1) parts of the study area, the dominant factor producing runoff is the excess of annual precipitation over annual potential evapotranspiration, but runoff caused by variability of supply and demand over time is also significant; in the arid (index of dryness >1) parts, all of the runoff is caused by variability

  14. Photosynthetic water splitting: 1987 annual report

    SciTech Connect

    Greenbaum, E.

    1988-01-01

    This document is an annual report of photosynthetic water splitting for the production of hydrogen and oxygen. Unicellular green algae are capable of evolving molecular hydrogen in the presence of carbon dioxide. Controlling factors that determine hydrogen evolution are either temperature or light intensity. Also, mutants of the green alga Chlamydomonas are capable of evolving hydrogen in the presence of carbon dioxide. The significance of these discoveries is that the presence of carbon dioxide (or bicarbonate) is a key factor in determining the activity of the Photosystem II water splitting complex. Second, a new advance in oxygen sensor technology has been made that, for the first time, allows the absolute measurement of photosynthetically evolved oxygen from a single colony of microalgae growing on a solidified agar medium. The key aspect of this electrochemical sensor is the utilization of ultra-pure potassium hydroxide as the electrolyte and a recognition of the role that electrolyte impurities play in contributing to base line noise. 9 refs., 8 figs., 2 tabs.

  15. Least limiting water range of soils

    USDA-ARS?s Scientific Manuscript database

    The least limiting water range (LLWR) has been developed as an index of the soil structural quality. The LLWR was defined as the region bounded by the upper and lower soil water content over which water, oxygen, and mechanical resistance become major limitations for root growth. Thus, it combines th...

  16. Recreational Water Quality Criteria Limits

    EPA Pesticide Factsheets

    This set of Frequently Asked Questions (FAQ) provides an overview of NPDES permitting applicable to continuous dischargers (such as POTWs) based on water quality standards for pathogens and pathogen indicators associated with fecal contamination.

  17. 5 CFR 630.908 - Limitations on donation of annual leave.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Limitations on donation of annual leave... REGULATIONS ABSENCE AND LEAVE Voluntary Leave Transfer Program § 630.908 Limitations on donation of annual... amount of annual leave he or she would be entitled to accrue during the leave year in which the...

  18. Consequences of limited seed dispersal within simulated annual populations.

    PubMed

    Bullock, Stephen H

    1976-09-01

    Theoretical analyses of the consequences of dispersal have been almost entirely limited to studies of colonization. A simulation model is constructed and analyzed to study the effects of dispersal within local plant populations. Rules for the growth and reproduction of individuals are deterministic and related only to competition with other plants. Rules for the dispersal of individual seeds are stochastic; the generalized seed shadow is negatively exponential. The analysis has several interesting results. 1) In small, dense populations of annuals, mortality and growth behavior are significantly affected by small-scale changes in dispersal. 2) Stable population size, at any life stage, is not environmentally fixed (e.g. by the number of safe sites) but is also a function of reproductive capacity and dispersal. 3) There is a minimum productive capability which must be exceeded for a population to be able to respond to increased dispersal. The responsive range of the parameters may be related to the grain of safe site distribution. 4) When the total number of seeds per generation is large, high dispersal decreases the number of germlings that are able to establish. 5) For plants that reach the growing stage, however, expected reproduction can exceed that of genotypes with greater reproductive capacity but less dispersal. 6) An uneven distribution of seeds is essential to a spatial patterning of mortality which can deter competitive extinction.

  19. 78 FR 48075 - Western Pacific Fisheries; 2013 Annual Catch Limits and Accountability Measures; Correcting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-07

    ... Catch Limits and Accountability Measures; Correcting Amendment AGENCY: National Marine Fisheries Service... limit specifications for western Pacific fisheries that were published in the Federal Register on March... Pacific Fishery Management Council (Council) recommended annual catch limits for western Pacific fisheries...

  20. 76 FR 17808 - Fisheries in the Western Pacific; Mechanism for Specifying Annual Catch Limits and Accountability...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-31

    ... Pacific; Mechanism for Specifying Annual Catch Limits and Accountability Measures AGENCY: National Marine... specifying annual catch limits (ACLs) and accountability measures (AMs) for western Pacific fisheries. The... specific areas, changing bag limits, or otherwise restricting effort or catch. Any inseason restriction...

  1. 76 FR 3091 - National Annual Catch Limit Science Workshop; Meeting Announcement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-19

    ... National Oceanic and Atmospheric Administration RIN 0648-XA133 National Annual Catch Limit Science Workshop... Limits (ACL) and Accountability Measures (AM). The meeting will be held on February 15-17, 2011, at the... Service is announcing a National Annual Catch Limit (ACL) Science Workshop on February 15-17, 2011, in...

  2. 75 FR 8245 - Natural Gas Pipelines; Project Cost and Annual Limits

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-24

    ... Energy Regulatory Commission 18 CFR Part 157 Natural Gas Pipelines; Project Cost and Annual Limits...) computes and publishes the project cost and annual limits for natural gas pipelines blanket construction... limits applicable from January 1, 2010 through December 31, 2010. FOR FURTHER INFORMATION CONTACT...

  3. 77 FR 8724 - Natural Gas Pipelines; Project Cost and Annual Limits

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-15

    ... Energy Regulatory Commission 18 CFR Part 157 Natural Gas Pipelines; Project Cost and Annual Limits... (OEP) computes and publishes the project cost and annual limits for natural gas pipelines blanket... establishes cost limits applicable from January 1, 2012 through December 31, 2012. FOR FURTHER INFORMATION...

  4. 78 FR 8389 - Natural Gas Pipelines; Project Cost and Annual Limits

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ... Energy Regulatory Commission 18 CFR Part 157 Natural Gas Pipelines; Project Cost and Annual Limits AGENCY... publishes the project cost and annual limits for natural gas pipelines blanket construction certificates for each calendar year. DATES: This final rule is effective February 6, 2013 and establishes cost limits...

  5. 76 FR 8293 - Natural Gas Pipelines; Project Cost and Annual Limits

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-14

    ... Energy Regulatory Commission 18 CFR Part 157 Natural Gas Pipelines; Project Cost and Annual Limits...) computes and publishes the project cost and annual limits for natural gas pipelines blanket construction.... Applicability date: This final rule establishes cost limits applicable from January 1, 2011 through December 31...

  6. Water limits to closing yield gaps

    NASA Astrophysics Data System (ADS)

    Davis, Kyle Frankel; Rulli, Maria Cristina; Garrassino, Francesco; Chiarelli, Davide; Seveso, Antonio; D'Odorico, Paolo

    2017-01-01

    Agricultural intensification is often seen as a suitable approach to meet the growing demand for agricultural products and improve food security. It typically entails the use of fertilizers, new cultivars, irrigation, and other modern technology. In regions of the world affected by seasonal or chronic water scarcity, yield gap closure is strongly dependent on irrigation (blue water). Global yield gap assessments have often ignored whether the water required to close the yield gap is locally available. Here we perform a gridded global analysis (10 km resolution) of the blue water consumption that is needed annually to close the yield gap worldwide and evaluate the associated pressure on renewable freshwater resources. We find that, to close the yield gap, human appropriation of freshwater resources for irrigation would have to increase at least by 146%. Most study countries would experience at least a doubling in blue water requirement, with 71% of the additional blue water being required by only four crops - maize, rice, soybeans, and wheat. Further, in some countries (e.g., Algeria, Morocco, Syria, Tunisia, and Yemen) the total volume of blue water required for yield gap closure would exceed sustainable levels of freshwater consumption (i.e., 40% of total renewable surface and groundwater resources).

  7. 50 CFR 648.230 - Spiny dogfish Annual Catch Limits (ACLs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Spiny dogfish Annual Catch Limits (ACLs... Management Measures for the Spiny Dogfish Fishery § 648.230 Spiny dogfish Annual Catch Limits (ACLs). (a) The Spiny Dogfish Monitoring Committee shall recommend to the Joint Spiny Dogfish Committee, an ACL for the...

  8. 50 CFR 648.230 - Spiny dogfish Annual Catch Limits (ACLs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Spiny dogfish Annual Catch Limits (ACLs... Management Measures for the Spiny Dogfish Fishery § 648.230 Spiny dogfish Annual Catch Limits (ACLs). (a) The Spiny Dogfish Monitoring Committee shall recommend to the Joint Spiny Dogfish Committee, an ACL for the...

  9. 26 CFR 54.9815-2711T - No lifetime or annual limits (temporary).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 17 2011-04-01 2011-04-01 false No lifetime or annual limits (temporary). 54... annual limits permissible prior to 2014—(1) In general. With respect to plan years beginning prior to January 1, 2014, a group health plan, or a health insurance issuer offering group health insurance...

  10. 29 CFR 2590.715-2711 - No lifetime or annual limits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 9 2011-07-01 2011-07-01 false No lifetime or annual limits. 2590.715-2711 Section 2590... regulations. (d) Restricted annual limits permissible prior to 2014—(1) In general. With respect to plan years beginning prior to January 1, 2014, a group health plan, or a health insurance issuer offering group health...

  11. 26 CFR 1.401(a)(17)-1 - Limitation on annual compensation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... authority to amend the plan means the legislature, board, commission, council, or other governing body with... effective date, annual compensation limit means $200,000, adjusted as provided by the Commissioner. The... after the OBRA '93 effective date, annual compensation limit means $150,000, adjusted as provided by the...

  12. 50 CFR 648.120 - Scup Annual Catch Limit (ACL).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... shall recommend to the MAFMC separate ACLs for the commercial and recreational scup fisheries, the sum... and recreational fishing sector ACLs will be established consistent with the allocation guidelines... recreational sector ACLs may be established on an annual basis for up to 3 years at a time, dependent...

  13. 50 CFR 648.290 - Tilefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... detailed review of fishery performance relative to the sector ACLs at least every 5 years. (1) If the ACL... recommendations to the MAFMC for changes in measures intended to ensure ACLs are not as frequently exceeded. (2...) Performance reviews shall not substitute for annual reviews that occur to ascertain if prior year ACLs...

  14. 50 CFR 648.290 - Tilefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... detailed review of fishery performance relative to the sector ACLs at least every 5 years. (1) If the ACL... recommendations to the MAFMC for changes in measures intended to ensure ACLs are not as frequently exceeded. (2...) Performance reviews shall not substitute for annual reviews that occur to ascertain if prior year ACLs...

  15. 50 CFR 648.120 - Scup Annual Catch Limit (ACL).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... shall recommend to the MAFMC separate ACLs for the commercial and recreational scup fisheries, the sum... and recreational fishing sector ACLs will be established consistent with the allocation guidelines... recreational sector ACLs may be established on an annual basis for up to 3 years at a time, dependent...

  16. Limited school drinking water access for youth

    PubMed Central

    Kenney, Erica L.; Gortmaker, Steven L.; Cohen, Juliana F.W.; Rimm, Eric B.; Cradock, Angie L.

    2016-01-01

    PURPOSE Providing children and youth with safe, adequate drinking water access during school is essential for health. This study utilized objectively measured data to investigate the extent to which schools provide drinking water access that meets state and federal policies. METHODS We visited 59 middle and high schools in Massachusetts during spring 2012. Trained research assistants documented the type, location, and working condition of all water access points throughout each school building using a standard protocol. School food service directors (FSDs) completed surveys reporting water access in cafeterias. We evaluated school compliance with state plumbing codes and federal regulations and compared FSD self-reports of water access with direct observation; data were analyzed in 2014. RESULTS On average, each school had 1.5 (SD: 0.6) water sources per 75 students; 82% (SD: 20) were functioning, and fewer (70%) were both clean and functioning. Less than half of the schools met the federal Healthy Hunger Free Kids Act requirement for free water access during lunch; 18 schools (31%) provided bottled water for purchase but no free water. Slightly over half (59%) met the Massachusetts state plumbing code. FSDs overestimated free drinking water access compared to direct observation (96% FSD-reported versus 48% observed, kappa=0.07, p=0.17). CONCLUSIONS School drinking water access may be limited. In this study, many schools did not meet state or federal policies for minimum student drinking water access. School administrative staff may not accurately report water access. Public health action is needed to increase school drinking water access. IMPLICATIONS AND CONTRIBUTIONS Adolescents’ water consumption is lower than recommended. In a sample of Massachusetts middle and high schools, about half did not meet federal and state minimum drinking water access policies. Direct observation may improve assessments of drinking water access and could be integrated into routine

  17. Water Budget, 1983-1985 Annual Report.

    SciTech Connect

    Maher, Mark

    1986-10-01

    This report encompasses the first three years (1983, 1984, and 1985) of operation. It includes: (1) background and history of the development of the Water Budget concept including a discussion of Water Budget manager positions; (2) implementation of the Water Budget since its formulation by the Council in 1983; (3) a discussion of the research and monitoring funded by BPA; and (4) a discussion of Section 304 of the Council's Program.

  18. Estimating annual charges for ambulatory care from limited utilization data.

    PubMed Central

    Saver, B G; Wagner, E H

    1995-01-01

    OBJECTIVE. This study explores the types of utilization information needed to produce a reasonable estimate of annual charges for ambulatory care that could be used in the absence of charge or cost data as an aggregate utilization measure. DATA SOURCE. Charge and utilization data from the RAND Health Insurance Experiment were used. STUDY DESIGN. Services provided to enrollees in the Health Insurance Experiment at each of the six sites for a one-year period were grouped into categories according to California Relative Value Studies (CRVS) codes. Using annual charges as the dependent variable, we evaluated linear regression models for their predictive accuracy, as indicated by adjusted R2-values. Categories of services were combined on the basis of clinical meaningfulness (e.g., all provider visits into one group), and predictive accuracy of models with these groupings of services examined. We examined model validity by applying the derived models to each of the 30 remaining site-years of data from the Health Insurance Experiment. PRINCIPAL FINDINGS. We were able to explain 84 percent of the variance in charges with a model containing counts of provider visits exclusive of mental health visits, mental health provider visits, days drugs were prescribed, days radiologic procedures were performed, procedural visits subdivided according to whether they were performed by a surgical or medical provider, days laboratory and/or pathology tests were performed, days a grouping of miscellaneous tests were performed, and days supplies were purchased. When applied to the validation data, this model predicted a mean of 77 percent of the variance and mean charges 102 +/- 9 percent of actual mean charges. A model with only the first four of the listed categories explained 77 percent of the variance in charges. CONCLUSIONS. Models using only counts of several broad categories of services perform rather well in predicting annual charges for ambulatory care. PMID:7860322

  19. Thermal-hydraulic limitations on water-cooled limiters

    SciTech Connect

    Cha, Y.S.; Misra, B.

    1984-08-01

    An assessment of the cooling requirements for fusion reactor components, such as the first wall and limiter/divertor, was carried out using pressurized water as the coolant. In order to establish the coolant operating conditions, a survey of the literature on departure from nucleate boiling, critical heat flux, asymmetrical heating and heat transfer augmentation techniques was carried out. The experimental data and the empirical correlations indicate that thermal protection for the fusion reactor components based on current design concepts can be provided with an adequate margin of safety without resorting to either high coolant velocities, excessive coolant pressures, or heat transfer augmentation techniques. If, however, the future designs require heat transfer enhancement techniques, experimental verification would be necessary since no data on heat transfer augmentation techniques exist for complex geometries, especially under asymmetrically heated conditions. Since the data presented herein concern primarily thermal protection, the final design should consider other factors such as thermal stresses, temperature limits, and fatigue.

  20. Water Science and Technology Board Annual Report 2001-2002

    SciTech Connect

    2002-10-01

    This annual report marks the twentieth anniversary of the Water Science and Technology Board (WSTB) (1982-2002). The WSTB oversees studies of water issues. The principal products of studies are written reports. These reports cover a wide range of water resources issues of national concern. The following three recently issued reports illustrate the scope of the WSTB's studies: Envisioning the Agenda for Water Resources Research in the Twenty-first Century. The Missouri River Ecosystem: Exploring the Prospects for Recovery, and Assessing the TMDL Approach to Water Quality Management. The WSTB generally meets three times each year where discussions are held on ongoing projects, strategic planning, and developing new initiatives. The meetings also foster communication within the water resources community. The annual report includes a discussion on current studies, completed studies 2001-2002, and future plans, as well as a listing of published reports (1983-2002).

  1. Limited School Drinking Water Access for Youth.

    PubMed

    Kenney, Erica L; Gortmaker, Steven L; Cohen, Juliana F W; Rimm, Eric B; Cradock, Angie L

    2016-07-01

    Providing children and youth with safe, adequate drinking water access during school is essential for health. This study used objectively measured data to investigate the extent to which schools provide drinking water access that meets state and federal policies. We visited 59 middle and high schools in Massachusetts during spring 2012. Trained research assistants documented the type, location, and working condition of all water access points throughout each school building using a standard protocol. School food service directors (FSDs) completed surveys reporting water access in cafeterias. We evaluated school compliance with state plumbing codes and federal regulations and compared FSD self-reports of water access with direct observation; data were analyzed in 2014. On average, each school had 1.5 (standard deviation: .6) water sources per 75 students; 82% (standard deviation: 20) were functioning and fewer (70%) were both clean and functioning. Less than half of the schools met the federal Healthy Hunger-Free Kids Act requirement for free water access during lunch; 18 schools (31%) provided bottled water for purchase but no free water. Slightly over half (59%) met the Massachusetts state plumbing code. FSDs overestimated free drinking water access compared to direct observation (96% FSD reported vs. 48% observed, kappa = .07, p = .17). School drinking water access may be limited. In this study, many schools did not meet state or federal policies for minimum student drinking water access. School administrative staff may not accurately report water access. Public health action is needed to increase school drinking water access. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  2. Ground Water Technical Support Center (GWTSC) Annual ...

    EPA Pesticide Factsheets

    The Ground Water Technical Support Center (GWTSC) is part of the Ground Water and Ecosystems Restoration Division (GWERD), which is based in the Robert S. Kerr Environmental Research Center in Ada, Oklahoma. The GWERD is a research division of U.S. EPA’s National Risk Management Research Laboratory (NRMRL). The GWTSC is one of an interlinked group of specialized Technical Support Centersthat were established under the Technical Support Project (TSP). The GWTSC provides technical support on issues related to groundwater. Specifically, the GWTSC provides technical support to U.S. EPA and State regulators for issues and problems related to:1. subsurface contamination (contaminants in ground water, soils and sediments),2. cross-media transfer (movement of contaminants from the subsurface to other media such as surface water or air), and3. restoration of impacted ecosystems.The GWTSC works with Remedial Project Managers (RPMs) and other decision makers to solve specific problems at Superfund, RCRA (Resource Conservation and Recovery Act), Brownfields sites, and ecosystem restoration sites. The Ground Water Technical Support Center (GWTSC) is part of the Ground Water and Ecosystems Restoration Division (GWERD), which is based in the Robert S. Kerr Environmental Research Center in Ada, Oklahoma. The GWERD is a research division of U.S. EPA’s National Risk Management Research Laboratory (NRMRL). The GWTSC is one of an interlinked group of specialized Technical Suppo

  3. Efficiency limits for photoelectrochemical water-splitting

    PubMed Central

    Fountaine, Katherine T.; Lewerenz, Hans Joachim; Atwater, Harry A.

    2016-01-01

    Theoretical limiting efficiencies have a critical role in determining technological viability and expectations for device prototypes, as evidenced by the photovoltaics community's focus on detailed balance. However, due to their multicomponent nature, photoelectrochemical devices do not have an equivalent analogue to detailed balance, and reported theoretical efficiency limits vary depending on the assumptions made. Here we introduce a unified framework for photoelectrochemical device performance through which all previous limiting efficiencies can be understood and contextualized. Ideal and experimentally realistic limiting efficiencies are presented, and then generalized using five representative parameters—semiconductor absorption fraction, external radiative efficiency, series resistance, shunt resistance and catalytic exchange current density—to account for imperfect light absorption, charge transport and catalysis. Finally, we discuss the origin of deviations between the limits discussed herein and reported water-splitting efficiencies. This analysis provides insight into the primary factors that determine device performance and a powerful handle to improve device efficiency. PMID:27910847

  4. Efficiency limits for photoelectrochemical water-splitting

    NASA Astrophysics Data System (ADS)

    Fountaine, Katherine T.; Lewerenz, Hans Joachim; Atwater, Harry A.

    2016-12-01

    Theoretical limiting efficiencies have a critical role in determining technological viability and expectations for device prototypes, as evidenced by the photovoltaics community's focus on detailed balance. However, due to their multicomponent nature, photoelectrochemical devices do not have an equivalent analogue to detailed balance, and reported theoretical efficiency limits vary depending on the assumptions made. Here we introduce a unified framework for photoelectrochemical device performance through which all previous limiting efficiencies can be understood and contextualized. Ideal and experimentally realistic limiting efficiencies are presented, and then generalized using five representative parameters--semiconductor absorption fraction, external radiative efficiency, series resistance, shunt resistance and catalytic exchange current density--to account for imperfect light absorption, charge transport and catalysis. Finally, we discuss the origin of deviations between the limits discussed herein and reported water-splitting efficiencies. This analysis provides insight into the primary factors that determine device performance and a powerful handle to improve device efficiency.

  5. 39 CFR 3010.12 - Source of CPI-U data for purposes of annual limitation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Source of CPI-U data for purposes of annual... FOR MARKET DOMINANT PRODUCTS Rules for Rate Adjustments for Rates of General Applicability (Type 1-A and 1-B Rate Adjustments) § 3010.12 Source of CPI-U data for purposes of annual limitation. The...

  6. 39 CFR 3010.20 - Test for compliance with the annual limitation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Test for compliance with the annual limitation. 3010.20 Section 3010.20 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL REGULATION OF RATES FOR MARKET DOMINANT PRODUCTS Rules for Applying the Price Cap § 3010.20 Test for compliance with the annual...

  7. 39 CFR 3010.22 - Calculation of less than annual limitation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Calculation of less than annual limitation. 3010.22 Section 3010.22 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL REGULATION OF RATES FOR MARKET DOMINANT PRODUCTS Rules for Applying the Price Cap § 3010.22 Calculation of less than annual...

  8. 5 CFR 630.1305 - Limitations on contribution of annual leave.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... leave. 630.1305 Section 630.1305 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS ABSENCE AND LEAVE Reservist Leave Bank Program § 630.1305 Limitations on contribution of annual...) A leave contributor may contribute only accrued unused annual leave to the reservist leave bank....

  9. 5 CFR 630.306 - Time limit for use of restored annual leave.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... leave. 630.306 Section 630.306 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS ABSENCE AND LEAVE Annual Leave § 630.306 Time limit for use of restored annual leave. (a) Except... leave restored under 5 U.S.C. 6304(d) must be scheduled and used not later than the end of the leave...

  10. 5 CFR 630.1115 - Limitations on the use of donated annual leave.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... leave. 630.1115 Section 630.1115 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS ABSENCE AND LEAVE Emergency Leave Transfer Program § 630.1115 Limitations on the use of donated annual leave. Donated annual leave transferred to a leave recipient under this subpart may not be— (a...

  11. 76 FR 53847 - New International Commission on Radiological Protection; Recommendations on the Annual Dose Limit...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ... REIRS database (NUREG-0713, ``Occupational Radiation Exposure at Commercial Nuclear Power Reactors and... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY... Annual Dose Limit to the Lens of the Eye AGENCY: Nuclear Regulatory Commission. ACTION: Request...

  12. 78 FR 26383 - Annual Indexing of Basic Statutory Mortgage Limits for Multifamily Housing Programs

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-06

    ... URBAN DEVELOPMENT Annual Indexing of Basic Statutory Mortgage Limits for Multifamily Housing Programs... Mortgage Limits for Multifamily Housing Programs for Calendar Year 2013. DATES: Effective Date: January 1... limits for FHA's multifamily mortgage programs collectively referred to as the ``Dollar Amounts.'' They...

  13. 76 FR 79704 - Annual Indexing of Basic Statutory Mortgage Limits for Multifamily Housing Programs

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-22

    ... URBAN DEVELOPMENT Annual Indexing of Basic Statutory Mortgage Limits for Multifamily Housing Programs... Mortgage Limits for Multifamily Housing Programs for Calendar Year 2012. DATES: Effective Date: January 1... are shown below: Basic Statutory Mortgage Limits For Calendar Year 2012 Multifamily Loan Program...

  14. 76 FR 10387 - Annual Indexing of Basic Statutory Mortgage Limits for Multifamily Housing Programs

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-24

    ... URBAN DEVELOPMENT Annual Indexing of Basic Statutory Mortgage Limits for Multifamily Housing Programs... Mortgage Limits for Multifamily Housing Programs for Calendar Year 2011. DATES: Effective Date: January 1... Dollar Amounts for Calendar Year 2011 are shown below: Basic Statutory Mortgage Limits for Calendar Year...

  15. Estimates of Annual Climatic Water Need in Introductory Geography

    ERIC Educational Resources Information Center

    Currey, Donald R.

    1976-01-01

    This paper compares briefly, within the regional context of the western United States, several of the more readily adoptable models that are being used or could be used to provide estimates of annual climatic water need appropriate to macroscale applications in introductory geography courses. (Author)

  16. The 16th James L. Waters Annual Symposium: Electrochemistry

    NASA Astrophysics Data System (ADS)

    Michael, Adrian C.

    2007-04-01

    The 16th Annual James L. Waters Symposium focused on electrochemistry, with emphasis on methods involving the flow of current. The speakers in this year's symposium are uniquely qualified to review the history of electroanalytical chemistry starting with Heyrovsky's initial studies and culminating with the present state of the art. Each has contributed significantly to the scientific, technical, and commercial development of the field.

  17. Annual Book of ASTM Standards, Part 23: Water; Atmospheric Analysis.

    ERIC Educational Resources Information Center

    American Society for Testing and Materials, Philadelphia, PA.

    Standards for water and atmospheric analysis are compiled in this segment, Part 23, of the American Society for Testing and Materials (ASTM) annual book of standards. It contains all current formally approved ASTM standard and tentative test methods, definitions, recommended practices, proposed methods, classifications, and specifications. One…

  18. Annual Book of ASTM Standards, Part 23: Water; Atmospheric Analysis.

    ERIC Educational Resources Information Center

    American Society for Testing and Materials, Philadelphia, PA.

    Standards for water and atmospheric analysis are compiled in this segment, Part 23, of the American Society for Testing and Materials (ASTM) annual book of standards. It contains all current formally approved ASTM standard and tentative test methods, definitions, recommended practices, proposed methods, classifications, and specifications. One…

  19. 77 FR 23652 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Comprehensive Annual Catch Limit...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-20

    ..., Gulf of Mexico, and South Atlantic; Comprehensive Annual Catch Limit Amendment Supplement AGENCY... regulations implementing the Comprehensive Annual Catch Limit Amendment (Comprehensive ACL Amendment) for the... Comprehensive ACL Amendment specified, in part, annual catch limits (ACLs) and accountability measures (AMs) for...

  20. 78 FR 59626 - Main Hawaiian Islands Deep 7 Bottomfish Annual Catch Limits and Accountability Measures for 2013-14

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-27

    ... Bottomfish Annual Catch Limits and Accountability Measures for 2013-14 AGENCY: National Marine Fisheries... specifications. SUMMARY: NMFS specifies an annual catch limit of 346,000 lb of Deep 7 bottomfish in the main... repeated here. Through this action, NMFS is specifying an annual catch limit (ACL) of 346,000 lb of Deep 7...

  1. 77 FR 42192 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Comprehensive Annual Catch Limit...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-18

    ..., Gulf of Mexico, and South Atlantic; Comprehensive Annual Catch Limit Amendment Supplement AGENCY... implementing the Comprehensive Annual Catch Limit Amendment (Comprehensive ACL Amendment) for the Fishery... Amendment specified, in part, annual catch limits (ACLs) and accountability measures (AMs) for species in...

  2. Mapping mean annual water yield and other hydrological variables for Alberta, Canada, 1971-2000

    NASA Astrophysics Data System (ADS)

    Mueller, M.; Kienzle, S. W.

    2011-12-01

    In Alberta, Canada, as in many other regions in the world, water is a limiting factor to population growth, economic development and environmental protection. The methods presented here were developed under a broader research project aimed to provide a water resources inventory for the province of Alberta. For 287 sub-watersheds, mean annual water yield, runoff coefficients, and actual evapotranspiration were computed from streamflow records and high resolution precipitation maps (PRISM) for the period 1971-2000. The analysis of the mean annual water yield is based on the association between the 287 gauged watershed areas and the respective streamflow production. Runoff coefficients were computed based on a spatial overlay of watershed boundaries and precipitation. Actual evapotranspiration was then computed by subtracting the mean annual water yield from the mean annual precipitation. Figure 1 shows a low resolution map example. The resulting maps are also available on the internet for 3 x 4' printouts and can be found by searching for "Alberta water yield". For 16 major watersheds in Alberta, the percent contribution of each sub-watershed is also listed.

  3. Water Science and Technology Board annual report 1988

    SciTech Connect

    Not Available

    1989-01-01

    This annual report of the Water Science and Technology Board (WSTB) summarizes the activities of the Board and its subgroups during 1988, its sixth year of existence. Included are descriptions of current and recently completed projects, new activities scheduled to begin in 1989, and plans for the future. The report also includes information on Board and committee memberships, program operational features, and reports produced during the past several years. This annual report is intended to provide an introduction to the WSTB and summary of its program for the year.

  4. An annual quasidifference approach to water price elasticity

    NASA Astrophysics Data System (ADS)

    Bell, David R.; Griffin, Ronald C.

    2008-08-01

    The preferred price specification for retail water demand estimation has not been fully settled by prior literature. Empirical consistency of price indices is necessary to enable testing of competing specifications. Available methods of unbiasing the price index are summarized here. Using original rate information from several hundred Texas utilities, new indices of marginal and average price change are constructed. Marginal water price change is shown to explain consumption variation better than average water price change, based on standard information criteria. Annual change in quantity consumed per month is estimated with differences in climate variables and the new quasidifference marginal price index. As expected, the annual price elasticity of demand is found to vary with daily high and low temperatures and the frequency of precipitation.

  5. Excess growing-season water limits lowland black spruce productivity

    NASA Astrophysics Data System (ADS)

    Dymond, S.; Kolka, R. K.; Bolstad, P. V.; Gill, K.; Curzon, M.; D'Amato, A. W.

    2015-12-01

    The annual growth of many tree species is limited by water availability, with growth increasing as water becomes less scarce. In lowland bogs of northern Minnesota, however, black spruce (Picea mariana) is often exposed to excess water via high water table elevations. These trees grow in thick deposits of organic mucky peat and often have shallow rooting systems to avoid the complete submersion of roots in water. While it is generally believed that black spruce decrease growth rates with rising water table elevations, this hypothesis has not been tested in situ. We used a unique, 50-year record of daily bog water table elevations at the Marcell Experimental Forest (MEF) in northern Minnesota to investigate the relationship between climate and black spruce productivity. Nine 1/20th ha circular plots were established in five different bogs and tree height, diameter-at-breast-height (DBH), and crown class were recorded. Additionally, two perpendicular cores were collected on all trees greater than 10 cm diameter-at-breast-height. Tree cores were sanded, mounted, cross-dated, and de-trended according to standard dendrochronological procedures. Ring width measurements were correlated with precipitation, temperature, and water table elevation using package BootRes in R to determine the climatic variables most associated with stand level productivity. Across the different plots, we found that early growing season water table elevation (May and June) was negatively correlated with both individual and stand-level black spruce growth (p < 0.01), while growth was positively correlated with March temperatures (p < 0.01). No significant relationships existed between black spruce growth and monthly precipitation. If summer water table elevations in these peatland ecosystems rise as is anticipated with more extreme precipitation events due to climate change, we could see an overall decrease in the stand level productivity of black spruce.

  6. Climate, interseasonal storage of soil water, and the annual water balance

    USGS Publications Warehouse

    Milly, P.C.D.

    1994-01-01

    The effects of annual totals and seasonal variations of precipitation and potential evaporation on the annual water balance are explored. It is assumed that the only other factor of significance to annual water balance is a simple process of water storage, and that the relevant storage capacity is the plant-available water-holding capacity of the soil. Under the assumption that precipitation and potential evaporation vary sinusoidally through the year, it is possible to derive an analytic solution of the storage problem, and this yields an expression for the fraction of precipitation that evaporates (and the fraction that runs off) as a function of three dimensionless numbers: the ratio of annual potential evaporation to annual precipitation (index of dryness); an index of the seasonality of the difference between precipitation and potential evaporation; and the ratio of plant-available water-holding capacity to annual precipitation. The solution is applied to the area of the United States east of 105??W, using published information on precipitation, potential evaporation, and plant-available water-holding capacity as inputs, and using an independent analysis of observed river runoff for model evaluation. The model generates an areal mean annual runoff of only 187 mm, which is about 30% less than the observed runoff (263 mm). The discrepancy is suggestive of the importance of runoff-generating mechanisms neglected in the model. These include intraseasonal variability (storminess) of precipitation, spatial variability of storage capacity, and finite infiltration capacity of land. ?? 1994.

  7. [Plant growth with limited water]. Performance report

    SciTech Connect

    Not Available

    1992-10-01

    When water is in short supply, soybean stem growth is inhibited by a physical limitation followed in a few hours by metabolic changes that reduce the extensibility of the cell walls. The extensibility then becomes the main limitation. With time, there is a modest recovery in extensibility along with an accumulation of a 28kD protein in the walls of the growth-affected cells. A 3lkD protein that was 80% similar in amino acid sequence also was present but did not accumulate in the walls of the stem cells. In the stem, growth was inhibited and the mRNA for the 28kD protein increased in response to water deprivation but the mRNA for the 3 1 kD protein did not. The roots continued to grow and the mRNA for the 28kD protein did not accumulate but the mRNA for the 3lkD protein did. Thus, there was a tissuespecific response of gene expression that correlated with the contrasting growth response to low water potential in the same seedlings. Further work using immunogold labeling, fluorescence labeling, and western blotting gave evidence that the 28kD protein is located in the cell wall as well as several compartments in the cytoplasm. Preliminary experiments indicate that the 28kD protein is a phosphatase.

  8. 5 CFR 630.302 - Maximum annual leave accumulation-forty-five day limitation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...-five day limitation. 630.302 Section 630.302 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT...—forty-five day limitation. (a) The effective date on which an employee (otherwise eligible thereunder... employee's accumulated and accrued annual leave is 30 days or less, he may carry forward the...

  9. 5 CFR 630.302 - Maximum annual leave accumulation-forty-five day limitation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...-five day limitation. 630.302 Section 630.302 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT...—forty-five day limitation. (a) The effective date on which an employee (otherwise eligible thereunder... employee's accumulated and accrued annual leave is 30 days or less, he may carry forward the...

  10. 5 CFR 630.302 - Maximum annual leave accumulation-forty-five day limitation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...-five day limitation. 630.302 Section 630.302 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT...—forty-five day limitation. (a) The effective date on which an employee (otherwise eligible thereunder... employee's accumulated and accrued annual leave is 30 days or less, he may carry forward the...

  11. 5 CFR 630.302 - Maximum annual leave accumulation-forty-five day limitation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...-five day limitation. 630.302 Section 630.302 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT...—forty-five day limitation. (a) The effective date on which an employee (otherwise eligible thereunder... employee's accumulated and accrued annual leave is 30 days or less, he may carry forward the...

  12. 5 CFR 630.1005 - Limitations on contribution of annual leave.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... leave. 630.1005 Section 630.1005 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS ABSENCE AND LEAVE Voluntary Leave Bank Program § 630.1005 Limitations on contribution of annual... shall establish written criteria permitting a leave bank board to waive the limitations on...

  13. Water Science and Technology Board annual report 1989

    SciTech Connect

    Not Available

    1990-01-01

    This report summarizes the activities of the Water Science and Technology Board (WSTB) and its subgroups during 1989, it seventh year of existence. It describes current and recently completed projects, new activities scheduled to begin in 1990, and plans for the future. The report also includes information on Board and committee memberships, program operational features, and reports produced during the past several years. This annual report is an introduction to the WSTB and its program for the year. 4 figs.

  14. ANNUAL WATER BUDGETS FOR A FORESTED SINKHOLE WETLAND

    SciTech Connect

    Hill, Dr. Andrew Jason; Neary, Vincent S

    2012-01-01

    Annual water budgets spanning two years, 2004 and 2005, are constructed for a sinkhole wetland in the Tennessee Highland Rim following conversion of 13 % of its watershed to impervious surfaces. The effect of watershed development on the hydrology of the study wetland was significant. Surface runoff was the dominant input, with a contribution of 61.4 % of the total. An average of 18.9 % of gross precipitation was intercepted by the canopy and evaporated. Seepage from the surface water body to the local groundwater system accounted for 83.1 % of the total outflow. Deep recharge varied from 43.2 % (2004) to 12.1 % (2005) of total outflow. Overall, evapotranspiration accounted for 72.4 % of the total losses, with an average of 65.7 % lost from soil profile storage. The annual water budgets indicate that deep recharge is a significant hydrologic function performed by isolated sinkhole wetlands, or karst pans, on the Tennessee Highland Rim. Continued hydrologic monitoring of sinkhole wetlands are needed to evaluate hydrologic function and response to anthropogenic impacts. The regression technique developed to estimate surface runoff entering the wetland is shown to provide reasonable annual runoff estimates, but further testing is needed.

  15. Limits of longitudinal decline for the interpretation of annual changes in FEV1 in individuals.

    PubMed

    Hnizdo, Eva; Sircar, Kanta; Yan, Tieliang; Harber, Philip; Fleming, James; Glindmeyer, Henry W

    2007-10-01

    Spirometry-based screening programmes often conduct annual assessment of longitudinal changes in forced expiratory volume in 1 second (FEV1) to identify individuals with excessive rates of decline. Both the American Thoracic Society (ATS) and the American College of Occupational and Environmental Medicine (ACOEM) recommend a reference limit value of > or =15% for excessive annual decline. Neither the ATS nor the ACOEM adjust this limit for the precision of the existing spirometry data. The authors propose an improved method of defining the reference limit of longitudinal annual FEV1 decline (LLD) based on the precision of the spirometry data. The authors used data from four monitoring programmes and measured their data precision using a pair-wise within-person variation statistic. They then derived programme- and gender-specific absolute and relative LLD values and validated these against the 95th percentiles for observed yearly changes in FEV1. The relative limit for annual decline was more practical than the absolute limit as it adjusted for gender differences in the magnitude of FEV1. The programme-specific relative limit values were in good agreement with 95th percentiles for year-to-year FEV1 changes and ranged from 6.6% to 15.8%. For individuals with COPD and bronchial hyperreactivity the 95th percentiles for year-to-year changes were about 15% and higher. The relative longitudinal limit for annual FEV1 decline based upon precision of measurements is valid and can be generalised to different gender and population groups. A relative limit of approximately 10% appears appropriate for good quality workplace monitoring programmes, whereas a limit of about 15% appears appropriate for clinical evaluation of individuals with an obstructive airway disease. Computer software based on the method described is available from the corresponding author.

  16. 78 FR 23288 - Proposed Information Collection: State Water Resources Research Institute Program; Annual...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-18

    ... application for an allotment grant and provides an annual report on its activities under the grant. The State... submit the annual application; and 80 hours (total) per grantee to complete the annual reports. Annual... Geological Survey Proposed Information Collection: State Water Resources Research Institute Program;...

  17. Reduced pollinator service and elevated pollen limitation at the geographic range limit of an annual plant.

    PubMed

    Moeller, David A; Geber, Monica A; Eckhart, Vincent M; Tiffin, Peter

    2012-05-01

    Mutualisms are well known to influence individual fitness and the population dynamics of partner species, but little is known about whether they influence species distributions and the location of geographic range limits. Here, we examine the contribution of plant-pollinator interactions to the geographic range limit of the California endemic plant Clarkia xantiana ssp. xantiana. We show that pollinator availability declined from the center to the margin of the geographic range consistently across four years of study. This decline in pollinator availability was caused to a greater extent by variation in the abundance of generalist rather than specialist bee pollinators. Climate data suggest that patterns of precipitation in the current and previous year drove variation in bee abundance because of its effects on cues for bee emergence in the current year and the abundance of floral resources in the previous year. Experimental floral manipulations showed that marginal populations had greater outcross pollen limitation of reproduction, in parallel with the decline in pollinator abundance. Although plants are self-compatible, we found no evidence that autonomous selfing contributes to reproduction, and thus no evidence that it alleviates outcross pollen limitation in marginal populations. Furthermore, we found no association between the distance to the range edge and selfing rate, as estimated from sequence and microsatellite variation, indicating that the mating system has not evolved in response to the pollination environment at the range periphery. Overall, our results suggest that dependence on pollinators for reproduction may be an important constraint limiting range expansion in this system.

  18. 40 CFR Appendix A to Part 72 - Methodology for Annualization of Emissions Limits

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Methodology for Annualization of Emissions Limits A Appendix A to Part 72 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Pt. 72, App. A Appendix A to Part 72—Methodology for...

  19. 40 CFR Appendix A to Part 72 - Methodology for Annualization of Emissions Limits

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Methodology for Annualization of Emissions Limits A Appendix A to Part 72 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Pt. 72, App. A Appendix A to Part 72—Methodology for...

  20. 50 CFR 622.49 - Annual catch limits (ACLs) and accountability measures (AMs).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Annual catch limits (ACLs) and accountability measures (AMs). 622.49 Section 622.49 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES OF THE CARIBBEAN, GULF, AND SOUTH ATLANTIC Management Measures §...

  1. 75 FR 5800 - Annual Indexing of Basic Statutory Mortgage Limits for Multifamily Housing Programs

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-04

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT Annual Indexing of Basic Statutory Mortgage Limits for Multifamily Housing Programs AGENCY: Office of the Assistant Secretary for Housing--Federal Housing Commissioner, HUD. ACTION: Notice...

  2. 38 CFR 3.26 - Section 306 and old-law pension annual income limitations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Section 306 and old-law pension annual income limitations. 3.26 Section 3.26 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS ADJUDICATION Pension, Compensation, and Dependency and Indemnity Compensation General § 3...

  3. 50 CFR 622.280 - Annual catch limits (ACLs) and accountability measures (AMs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... MEXICO, AND SOUTH ATLANTIC Dolphin and Wahoo Fishery Off the Atlantic States § 622.280 Annual catch limits (ACLs) and accountability measures (AMs). (a) Atlantic dolphin—(1) Commercial sector. If commercial landings for Atlantic dolphin, as estimated by the SRD, reach or are projected to reach...

  4. 50 CFR 622.280 - Annual catch limits (ACLs) and accountability measures (AMs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... MEXICO, AND SOUTH ATLANTIC Dolphin and Wahoo Fishery Off the Atlantic States § 622.280 Annual catch limits (ACLs) and accountability measures (AMs). (a) Atlantic dolphin—(1) Commercial sector. (i) If commercial landings for Atlantic dolphin, as estimated by the SRD, reach or are projected to reach...

  5. Annual cycle and destruction of Eighteen Degree Water

    NASA Astrophysics Data System (ADS)

    Billheimer, Sam; Talley, Lynne D.

    2016-09-01

    Eighteen Degree Water (EDW), the subtropical mode water of the western North Atlantic, is a voluminous, weakly stratified upper ocean water mass that acts as a subsurface reservoir of heat, nutrients, and CO2. This thick layer persists throughout the year, but nearly half of its volume is dispersed or mixed away, diffusing its properties into the thermocline, from the time it outcrops in winter until it is renewed the following year. CTD observations from Argo profiling floats and acoustically tracked, isothermally bound profiling floats are used to quantify EDW destruction rates and investigate the relevant processes responsible for the large annual cycle of EDW. EDW destruction occurs primarily at the top of the EDW layer, with the highest EDW destruction rates occurring during early summer. Slower, steadier EDW destruction is observed in early winter. EDW destruction is dominated by 1-D vertical diffusion, while mesoscale, along-isopycnal stirring is also significant, explaining approximately 1/3 of the total annual EDW destruction. Destruction via along-isopycnal processes is more prevalent near the Gulf Stream than in the southern Sargasso Sea, due to higher potential vorticity gradients and enhanced mesoscale activity.

  6. 77 FR 66744 - Temporary Rule to Increase the Commercial Annual Catch Limit for South Atlantic Yellowtail Snapper

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-07

    ... the Commercial Annual Catch Limit for South Atlantic Yellowtail Snapper AGENCY: National Marine... catch limit (ACL) for yellowtail snapper, as requested by the South Atlantic Fishery Management Council... Annual Catch Limit Amendment (Comprehensive ACL Amendment) to the Fishery Management Plan (FMP) for the...

  7. 78 FR 52125 - Main Hawaiian Islands Deep 7 Bottomfish Annual Catch Limits and Accountability Measures for 2013-14

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-22

    ... Bottomfish Annual Catch Limits and Accountability Measures for 2013-14 AGENCY: National Marine Fisheries... specifications; request for comments. SUMMARY: NMFS proposes to specify an annual catch limit of 346,000 lb for... catch limit is projected to be reached, NMFS would close the commercial and non-commercial fisheries for...

  8. 78 FR 57378 - Proposed Information Collection Request; Comment Request; Annual Public Water System Compliance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-18

    ... AGENCY Proposed Information Collection Request; Comment Request; Annual Public Water System Compliance... Protection Agency is planning to submit an information collection request (ICR), ``Annual Public Water System... available to the public, and submit to the Administrator of EPA, an annual report of violations of...

  9. 29 CFR 2520.104-44 - Limited exemption and alternative method of compliance for annual reporting by unfunded plans and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... annual reporting by unfunded plans and by certain insured plans. 2520.104-44 Section 2520.104-44 Labor... Limited exemption and alternative method of compliance for annual reporting by unfunded plans and by... this section is not required to comply with the annual reporting requirements described in paragraph...

  10. 5 CFR 630.307 - Time limit for use of restored annual leave-former missing employees.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... leave-former missing employees. 630.307 Section 630.307 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS ABSENCE AND LEAVE Annual Leave § 630.307 Time limit for use of restored annual leave—former missing employees. Annual leave restored under section 5562 of title 5, United States...

  11. 5 CFR 630.309 - Time limit for use of restored annual leave-extended exigency of the public business.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... leave-extended exigency of the public business. 630.309 Section 630.309 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS ABSENCE AND LEAVE Annual Leave § 630.309 Time limit for use of restored annual leave—extended exigency of the public business. (a) Annual leave restored...

  12. Monthly Paleostreamflow Reconstruction from Annual Dendrochronologies for Water Systems Analysis

    NASA Astrophysics Data System (ADS)

    Stagge, J. H.; Rosenberg, D. E.; DeRose, R. J.; Rittenour, T. M.

    2016-12-01

    With concerns about drought and hydroclimatic change in the Western US, water managers have increasingly sought to evaluate system vulnerability using paleo-reconstructed streamflows. However, the widespread adoption of these approaches in the water resources field has been slowed due to the temporal scale mismatch between tree-ring chronologies, measured at an annual resolution, and water systems models, which typically simulate decisions at monthly or daily scales. This study presents a novel approach to address this challenge, generating monthly paleo-streamflow reconstructions by disaggregating an existing time series of annual reconstructed streamflows. The method relies on tree-ring anomalies from regionally different species and sites to accurately adjust the seasonal hydrograph, while also incorporating reconstructions of global-scale climate patterns, such as the El Nino Southern Oscillation (ENSO) or Pacific Decadal Oscillation (PDO), as hydrograph predictors. In this way, the model combines local, regional, and global measures in an approach that is flexible enough for use at any site with sufficient tree-ring data. An example is presented using two sites in the Bear River watershed, located in northeastern Utah. Monthly flows, disaggregated using 50 tree-ring chronologies and ENSO/PDO reconstructions, accurately reproduce seasonal patterns, extreme events, and flows outside the typical tree ring growth season. This approach is unique within the paleo-hydrology field, due to its direct reconstruction of monthly flows without the need for more complex hydrologic models. Retained model covariates can also provide insights into the drivers of local hydrological droughts. Ultimately, the proposed method can greatly improve the implementation of paleo-reconstructed streamflows in water resources management, allowing for easier and more accurate simulations of water vulnerability in the Western US over a wider range of historic natural variability.

  13. Water Science and Technology Board annual report 1987

    SciTech Connect

    Not Available

    1988-01-01

    In 1982, the National Research Council chose to recognize the importance of water resource issues by establishing the Water Science and Technology Board (WSTB). During the five years since its first meeting in November 1982, the WSTB has grown and matured. The WSTB has met 14 times to provide guidance and plan activities. Under the WSTB's direction, committees of experts have conducted approximately 30 studies on a broad array of topics, from dam safety to irrigation-induced water quality problems to ground water protection strategies. Studies have ranged in scope from the oversight of specific agency projects and programs to broader scientific reviews, such as a disciplinary assessment of the hydrologic sciences initiated in 1987. In all cases, studies have the general theme of ultimately improving the scientific and technological bases of programs of water management and environmental quality. This fifth annual report of the WSTB summarizes the Board's accomplishments during 1987, its current activities, and its plans for the future. The report also includes information on Board and committee memberships, program organizations, and the reports produced. The report should provide the reader with a basic understanding of the WSTB's interests, achievements, and capabilities. The WSTB welcomes inquiries and suggestions concerning its activities and will provide more detailed information on any aspects of its work to those interested.

  14. Optimal root profiles in water-limited ecosystems

    NASA Astrophysics Data System (ADS)

    Rudd, Keith; Albertson, John D.; Ferrari, Silvia

    2014-09-01

    The vertical distribution of roots in the soil is of central importance to the mass and energy exchange between the land and the atmosphere. It has been demonstrated that the vertical root profiles which maximize transpiration in numerical experiments reflect well the characteristics of root profiles observed in nature for water-limited ecosystems. Previous research has demonstrated how the optimal vertical root profile depends on both the mean annual precipitation (MAP) and the soil texture. Recently, in the climate literature, it has been suggested Chou et al. (2012) [5] that increased greenhouse forcing in the tropics can lead to a simultaneous decrease in the frequency and increase in the intensity of precipitation. In this paper we demonstrate how such a change in the statistical structure of rainfall, even with no change to MAP, requires deeper root distributions to maintain optimal water use. These results raise interesting questions for future studies of nutrient dynamics, the cost of additional below ground carbon allocation, and inter plant functional type competition.

  15. Demand-driven resource investment in annual seed production by a perennial angiosperm precludes resource limitation.

    PubMed

    Ida, Takashi Y; Harder, Lawrence D; Kudo, Gaku

    2013-01-01

    The limits on annual seed production have long been characterized as restriction by either pollination success or resource provision to seed development. This expected dichotomy between pollen and resource limitation is based on the assumption that reproductive resources are fixed, which is reasonable for semelparous species. In contrast, iteroparity can ease the constraints on reproductive output per breeding season, if resources can be either mobilized from past storage or borrowed against future performance. For perennial plants, these options allow enhanced reproductive investment in response to unusually good pollination, so that annual seed production may not be pollen or resource limited. We assessed demand-governed reproductive investment by manipulating both resource supply capacity (partial defoliation) and resource demand (pollination quality: fully self-pollination, fully cross-pollination, or combinations of partial self- and cross-pollination within the inflorescence) for a forest herb, Stenanthium occidentale, which is subject to strong pre-dispersal inbreeding depression. Insensitivity to partial defoliation indicated that reproductive output was not source regulated. Instead, demand by developing seeds governs resource distribution, as demonstrated by elevated photosynthate translocation to fruits on fully cross-pollinated plants and the ability of completely defoliated plants to produce seeds. Such contingent resource allocation eliminates a simple dichotomy between pollen receipt and resource availability as limits on annual seed production. Instead, such flexible reproductive investment allows iteroparous perennials to participate maximally in current reproduction (as determined by ovule production) following superior pollination, or to conserve resources for future reproduction following poor pollination.

  16. Water balance model for mean annual hydrogen and oxygen isotope distributions in surface waters of the contiguous United States

    NASA Astrophysics Data System (ADS)

    Bowen, Gabriel J.; Kennedy, Casey D.; Liu, Zhongfang; Stalker, Jeremy

    2011-12-01

    The stable H and O isotope composition of river and stream water records information on runoff sources and land-atmosphere water fluxes within the catchment and is a potentially powerful tool for network-based monitoring of ecohydrological systems. Process-based hydrological models, however, have thus far shown limited power to replicate observed large-scale variation in U.S. surface water isotope ratios. Here we develop a geographic information system-based model to predict long-term annual average surface water isotope ratios across the contiguous United States. We use elevation-explicit, gridded precipitation isotope maps as model input and data from a U.S. Geological Survey monitoring program for validation. We find that models incorporating monthly variation in precipitation-evapotranspiration (P-E) amounts account for the majority (>89%) of isotopic variation and have reduced regional bias relative to models that do not consider intra-annual P-E effects on catchment water balance. Residuals from the water balance model exhibit strong spatial patterning and correlations that suggest model residuals isolate additional hydrological signal. We use interpolated model residuals to generate optimized prediction maps for U.S. surface water δ2H and δ18O values. We show that the modeled surface water values represent a relatively accurate and unbiased proxy for drinking water isotope ratios across the United States, making these data products useful in ecological and criminal forensics applications that require estimates of the local environmental water isotope variation across large geographic regions.

  17. Limiting invasive species in ballast water

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2011-06-01

    Ballast water is often intentionally loaded onto cargo ships and other vessels to provide weight necessary for safe maneuvering. However, this practice can unintentionally transport exotic organisms to parts of the world where populations of these organisms can establish themselves in new habitats as invasive and environmentally and economically disruptive species. Each year, an estimated 196 million metric tons of ballast water are discharged into U.S. coastal waters and the Great Lakes alone from an average of more than 90,000 visits of commercial ships greater than 300 metric tons, according to a 2 June report by the U.S. National Research Council (NRC) of the National Academies.

  18. On the use of a water balance to evaluate inter-annual terrestrial ET variability

    USDA-ARS?s Scientific Manuscript database

    Accurately measuring inter-annual variability in terrestrial evapotranspiration (ET) is a major challenge for efforts to detect inter-annual variability in the hydrologic cycle. Based on comparisons with annual ET values derived from a terrestrial water balance analysis, past research has cast doubt...

  19. Water chemistry, seepage investigation, streamflow, reservoir storage, and annual availability of water for the San Juan-Chama Project, northern New Mexico, 1942-2010

    USGS Publications Warehouse

    McKean, Sarah E.; Anderholm, Scott K.

    2014-01-01

    at Azotea Tunnel Outlet occurred from May through June, with a median duration of slightly longer than a month. Years with higher maximum daily streamflow generally are associated with higher annual streamflow than years with lower maximum daily streamflow. The amount of water that can be diverted for the SJCP is controlled by the availability of streamflow and is limited by several factors including legal limits for diversion, limits from the SJCP infrastructure including the size of the diversion dams and tunnels, the capacity of Heron Reservoir, and operational constraints that limit when water can be diverted. The average annual streamflow at Azotea Tunnel Outlet was 94,710 acre-feet, and the annual streamflow at Azotea Tunnel Outlet was approximately 75 percent of the annual streamflow available for the SJCP. The average annual percentage of available streamflow not diverted for the SJCP was 14 percent because of structural limitations of the capacity of infrastructure, 1 percent because of limitations of the reservoir storage capacity, and 29 percent because of the limitations from operations. For most years, the annual available streamflow not diverted for unknown reasons exceeded the sum of the water not diverted because of structural, capacity, and operational limitations.

  20. Bioenergy sorghum crop model predicts VPD-limited transpiration traits enhance biomass yield in water-limited environments

    DOE PAGES

    Truong, Sandra K.; McCormick, Ryan F.; Mullet, John E.

    2017-03-21

    Bioenergy sorghum is targeted for production in water-limited annual cropland therefore traits that improve plant water capture, water use efficiency, and resilience to water deficit are necessary to maximize productivity. A crop modeling framework, APSIM, was adapted to predict the growth and biomass yield of energy sorghum and to identify potentially useful traits for crop improvement. APSIM simulations of energy sorghum development and biomass accumulation replicated results from field experiments across multiple years, patterns of rainfall, and irrigation schemes. Modeling showed that energy sorghum’s long duration of vegetative growth increased water capture and biomass yield by ~30% compared to shortmore » season crops in a water-limited production region. Additionally, APSIM was extended to enable modeling of VPD-limited transpiration traits that reduce crop water use under high vapor pressure deficits (VPDs). The response of transpiration rate to increasing VPD was modeled as a linear response until a VPD threshold was reached, at which the slope of the response decreases, representing a range of responses to VPD observed in sorghum germplasm. Simulation results indicated that the VPD-limited transpiration trait is most beneficial in hot and dry regions of production where crops are exposed to extended periods without rainfall during the season or to a terminal drought. In these environments, slower but more efficient transpiration increases biomass yield and prevents or delays the exhaustion of soil water and onset of leaf senescence. The VPD-limited transpiration responses observed in sorghum germplasm increased biomass accumulation by 20% in years with lower summer rainfall, and the ability to drastically reduce transpiration under high VPD conditions could increase biomass by 6% on average across all years. This work indicates that the productivity and resilience of bioenergy sorghum grown in water-limited environments could be further enhanced by

  1. Bioenergy Sorghum Crop Model Predicts VPD-Limited Transpiration Traits Enhance Biomass Yield in Water-Limited Environments.

    PubMed

    Truong, Sandra K; McCormick, Ryan F; Mullet, John E

    2017-01-01

    Bioenergy sorghum is targeted for production in water-limited annual cropland therefore traits that improve plant water capture, water use efficiency, and resilience to water deficit are necessary to maximize productivity. A crop modeling framework, APSIM, was adapted to predict the growth and biomass yield of energy sorghum and to identify potentially useful traits for crop improvement. APSIM simulations of energy sorghum development and biomass accumulation replicated results from field experiments across multiple years, patterns of rainfall, and irrigation schemes. Modeling showed that energy sorghum's long duration of vegetative growth increased water capture and biomass yield by ~30% compared to short season crops in a water-limited production region. Additionally, APSIM was extended to enable modeling of VPD-limited transpiration traits that reduce crop water use under high vapor pressure deficits (VPDs). The response of transpiration rate to increasing VPD was modeled as a linear response until a VPD threshold was reached, at which the slope of the response decreases, representing a range of responses to VPD observed in sorghum germplasm. Simulation results indicated that the VPD-limited transpiration trait is most beneficial in hot and dry regions of production where crops are exposed to extended periods without rainfall during the season or to a terminal drought. In these environments, slower but more efficient transpiration increases biomass yield and prevents or delays the exhaustion of soil water and onset of leaf senescence. The VPD-limited transpiration responses observed in sorghum germplasm increased biomass accumulation by 20% in years with lower summer rainfall, and the ability to drastically reduce transpiration under high VPD conditions could increase biomass by 6% on average across all years. This work indicates that the productivity and resilience of bioenergy sorghum grown in water-limited environments could be further enhanced by development

  2. Bioenergy Sorghum Crop Model Predicts VPD-Limited Transpiration Traits Enhance Biomass Yield in Water-Limited Environments

    PubMed Central

    Truong, Sandra K.; McCormick, Ryan F.; Mullet, John E.

    2017-01-01

    Bioenergy sorghum is targeted for production in water-limited annual cropland therefore traits that improve plant water capture, water use efficiency, and resilience to water deficit are necessary to maximize productivity. A crop modeling framework, APSIM, was adapted to predict the growth and biomass yield of energy sorghum and to identify potentially useful traits for crop improvement. APSIM simulations of energy sorghum development and biomass accumulation replicated results from field experiments across multiple years, patterns of rainfall, and irrigation schemes. Modeling showed that energy sorghum's long duration of vegetative growth increased water capture and biomass yield by ~30% compared to short season crops in a water-limited production region. Additionally, APSIM was extended to enable modeling of VPD-limited transpiration traits that reduce crop water use under high vapor pressure deficits (VPDs). The response of transpiration rate to increasing VPD was modeled as a linear response until a VPD threshold was reached, at which the slope of the response decreases, representing a range of responses to VPD observed in sorghum germplasm. Simulation results indicated that the VPD-limited transpiration trait is most beneficial in hot and dry regions of production where crops are exposed to extended periods without rainfall during the season or to a terminal drought. In these environments, slower but more efficient transpiration increases biomass yield and prevents or delays the exhaustion of soil water and onset of leaf senescence. The VPD-limited transpiration responses observed in sorghum germplasm increased biomass accumulation by 20% in years with lower summer rainfall, and the ability to drastically reduce transpiration under high VPD conditions could increase biomass by 6% on average across all years. This work indicates that the productivity and resilience of bioenergy sorghum grown in water-limited environments could be further enhanced by development

  3. Contrasting precipitation seasonality influences evapotranspiration dynamics in water-limited shrublands

    NASA Astrophysics Data System (ADS)

    Villarreal, Samuel; Vargas, Rodrigo; Yepez, Enrico A.; Acosta, Jose S.; Castro, Angel; Escoto-Rodriguez, Martin; Lopez, Eulogio; Martínez-Osuna, Juan; Rodriguez, Julio C.; Smith, Stephen V.; Vivoni, Enrique R.; Watts, Christopher J.

    2016-02-01

    Water-limited ecosystems occupy nearly 30% of the Earth, but arguably, the controls on their ecosystem processes remain largely uncertain. We analyzed six site years of eddy covariance measurements of evapotranspiration (ET) from 2008 to 2010 at two water-limited shrublands: one dominated by winter precipitation (WP site) and another dominated by summer precipitation (SP site), but with similar solar radiation patterns in the Northern Hemisphere. We determined how physical forcing factors (i.e., net radiation (Rn), soil water content (SWC), air temperature (Ta), and vapor pressure deficit (VPD)) influence annual and seasonal variability of ET. Mean annual ET at SP site was 455 ± 91 mm yr-1, was mainly influenced by SWC during the dry season, by Rn during the wet season, and was highly sensitive to changes in annual precipitation (P). Mean annual ET at WP site was 363 ± 52 mm yr-1, had less interannual variability, but multiple variables (i.e., SWC, Ta, VPD, and Rn) were needed to explain ET among years and seasons. Wavelet coherence analysis showed that ET at SP site has a consistent temporal coherency with Ta and P, but this was not the case for ET at WP site. Our results support the paradigm that SWC is the main control of ET in water-limited ecosystems when radiation and temperature are not the limiting factors. In contrast, when P and SWC are decoupled from available energy (i.e., radiation and temperature), then ET is controlled by an interaction of multiple variables. Our results bring attention to the need for better understanding how climate and soil dynamics influence ET across these globally distributed ecosystems.

  4. 78 FR 62331 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Sub-Annual Catch Limit...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-17

    ... Northeastern United States; Atlantic Herring Fishery; Sub-Annual Catch Limit (ACL) Harvested for Management...), optimum yield, domestic harvest and processing, U.S. at-sea processing, border transfer, and sub-ACLs for each management area. The 2013 Domestic Annual Harvest is 107,800 metric tons (mt); the 2013...

  5. 78 FR 63406 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Sub-Annual Catch Limit...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-24

    ... Northeastern United States; Atlantic Herring Fishery; Sub-Annual Catch Limit (ACL) Harvested for Management..., and sub-ACLs for each management area. The 2013 Domestic Annual Harvest is 107,800 metric tons (mt); the 2013 sub-ACL allocated to Area 3 is 42,000 mt, and 0 mt of the sub-ACL is set aside for...

  6. 5 CFR 630.1111 - Limitation on the amount of donated annual leave received by an emergency leave recipient.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... annual leave received by an emergency leave recipient. 630.1111 Section 630.1111 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS ABSENCE AND LEAVE Emergency Leave Transfer Program § 630.1111 Limitation on the amount of donated annual leave received by an emergency leave...

  7. Limited irrigation research and infrared thermometry for detecting water stress

    USDA-ARS?s Scientific Manuscript database

    The USDA-ARS Limited Irrigation Research Farm, located outside of Greeley Colorado, is an experiment evaluating management perspectives of limited irrigation water. An overview of the farm systems is shown, including drip irrigation systems, water budgeting, and experimental design, as well as preli...

  8. Horton goes underground: on the relationship between shallow and deep storage in water-limited catchments

    NASA Astrophysics Data System (ADS)

    Brena-Naranjo, J. A.; Arciniega, S.; Troch, P. A. A.

    2016-12-01

    In water-limited catchments, hydrological partitioning at the catchment scale is characterized by high evaporation rates and low streamflow. This results in Horton indices (average ratio of evaporation to wetting) that are close to one. This suggests that catchment terrestrial ecosystems use most of the stored amount of plant-available water (wetting), with limited amounts of shallow storage for baseflow. Although the controls and feedbacks in these environments between wetting and evapotranspiration & vegetation dynamics are well understood, little is known about the relationship between shallow (Ss) and deep storage (Sd) at the catchment scale, its spatial variability and the climate & landscape characteristics that control such relationship. This paper presents work that analyzed catchment-scale dynamics of the maximum annual Ss and Sd in a set of 33 catchments located in water-limited environments (long-term aridity index > 1) of Mexico. Maximum Ss was computed using the daily water balance and maximum Sd was derived from baseflow separation. Results showed overall positive moderate to strong and statistically significant correlation between the two types of storage for 32 catchments. Linear regressions between a set of 19 climate variables and landscape parameters revealed that Ss and Sd are primarily controlled by the amount of annual wetting and the Horton Index, respectively. In contrast, shallow storage could not be predicted by the Horton index while deep storage could not be predicted by the annual amount of wetting. Moreover, the flow duration curves of the studied catchments depend strongly on the Horton index. We conclude that in water-limited regions, the maximum amount of deep storage (and subsequent the low flows that sustain riparian ecosystems) depends on the rainwater use efficiency of the terrestrial ecosystem, but the maximum amount of shallow storage (and subsequent overland flow generation) is intrinsically linked to soil water dynamics

  9. Health Risks of Limited-Contact Water Recreation

    PubMed Central

    Pratap, Preethi; Wroblewski, Meredith; Hryhorczuk, Daniel O.; Li, Hong; Liu, Li C.; Scheff, Peter A.

    2011-01-01

    Background: Wastewater-impacted waters that do not support swimming are often used for boating, canoeing, fishing, kayaking, and rowing. Little is known about the health risks of these limited-contact water recreation activities. Objectives: We evaluated the incidence of illness, severity of illness, associations between water exposure and illness, and risk of illness attributable to limited-contact water recreation on waters dominated by wastewater effluent and on waters approved for general use recreation (such as swimming). Methods: The Chicago Health, Environmental Exposure, and Recreation Study was a prospective cohort study that evaluated five health outcomes among three groups of people: those who engaged in limited-contact water recreation on effluent-dominated waters, those who engaged in limited-contact recreation on general-use waters, and those who engaged in non–water recreation. Data analysis included survival analysis, logistic regression, and estimates of risk for counterfactual exposure scenarios using G-computation. Results: Telephone follow-up data were available for 11,297 participants. With non–water recreation as the reference group, we found that limited-contact water recreation was associated with the development of acute gastrointestinal illness in the first 3 days after water recreation at both effluent-dominated waters [adjusted odds ratio (AOR) 1.46; 95% confidence interval (CI): 1.08, 1.96] and general-use waters (1.50; 95% CI: 1.09, 2.07). For every 1,000 recreators, 13.7 (95% CI: 3.1, 24.9) and 15.1 (95% CI: 2.6, 25.7) cases of gastrointestinal illness were attributable to limited-contact recreation at effluent-dominated waters and general-use waters, respectively. Eye symptoms were associated with use of effluent-dominated waters only (AOR 1.50; 95% CI: 1.10, 2.06). Among water recreators, our results indicate that illness was associated with the amount of water exposure. Conclusions: Limited-contact recreation, both on effluent

  10. The dynamic of annual carbon allocation to wood in European forests is consistent with a combined source-sink limitation of growth: implications for modelling

    NASA Astrophysics Data System (ADS)

    Guillemot, J.; Martin-StPaul, N. K.; Dufrêne, E.; François, C.; Soudani, K.; Ourcival, J. M.; Delpierre, N.

    2015-02-01

    The extent to which forest growth is limited by carbon (C) supply (source control) or by cambial activity (sink control) will condition the response of trees to global changes. However, the physiological processes responsible for the limitation of forest growth are still under debate. The aim of this study is to evaluate the key drivers of the annual carbon allocation to wood along large soil and climate regional gradients in five tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex, Quercus robur and Picea abies). Combining field measurements and process-based simulations at 49 sites (931 site-years), we assessed the stand biomass growth dependences at both inter-site and inter-annual scales. Specifically, the relative influence of forest C balance (source control), direct environmental control (water and temperature controls of sink activity) and allocation adjustments related to age, past climate conditions, competition intensity and soil nutrient availability on growth were quantified. The inter-site variability in stand C allocation to wood was predominantly driven by an age-related decline. The direct control of temperature or water stress on sink activity (i.e. independently from their effects on C supply) exerted a strong influence on the annual stand woody growth in all the species considered, including deciduous temperate species. The lagged effect of the past environment conditions was a significant driver of the annual C allocation to wood. Carbon supply appeared to strongly limit growth only in deciduous temperate species. We provide an evaluation of the spatio-temporal dynamics of annual carbon allocation to wood in European forests. Our study supports the premise that European forest growth is under a complex control including both source and sink limitations. The relative influences of the different growth drivers strongly vary across years and spatial ecological gradients. We suggest a

  11. Stand-level variation in evapotranspiration in non-water-limited eucalypt forests

    NASA Astrophysics Data System (ADS)

    Benyon, Richard G.; Nolan, Rachael H.; Hawthorn, Sandra N. D.; Lane, Patrick N. J.

    2017-08-01

    To better understand water and energy cycles in forests over years to decades, measurements of spatial and long-term temporal variability in evapotranspiration (Ea) are needed. In mountainous terrain, plot-level measurements are important to achieving this. Forest inventory data including tree density and size measurements, often collected repeatedly over decades, sample the variability occurring within the geographic and topographic range of specific forest types. Using simple allometric relationships, tree stocking and size data can be used to estimate variables including sapwood area index (SAI), which may be strongly correlated with annual Ea. This study analysed plot-level variability in SAI and its relationship with overstorey and understorey transpiration, interception and evaporation over a 670 m elevation gradient, in non-water-limited, even-aged stands of Eucalyptus regnans F. Muell. to determine how well spatial variation in annual Ea from forests can be mapped using SAI. Over the 3 year study, mean sap velocity in five E. regnans stands was uncorrelated with overstorey sapwood area index (SAI) or elevation: annual transpiration was predicted well by SAI (R2 0.98). Overstorey and total annual interception were positively correlated with SAI (R2 0.90 and 0.75). Ea from the understorey was strongly correlated with vapour pressure deficit (VPD) and net radiation (Rn) measured just above the understorey, but relationships between understorey Ea and VPD and Rn differed between understorey types and understorey annual Ea was not correlated with SAI. Annual total Ea was also strongly correlated with SAI: the relationship being similar to two previous studies in the same region, despite differences in stand age and species. Thus, spatial variation in annual Ea can be reliably mapped using measurements of SAI.

  12. The dynamic of the annual carbon allocation to wood in European tree species is consistent with a combined source-sink limitation of growth: implications for modelling

    NASA Astrophysics Data System (ADS)

    Guillemot, J.; Martin-StPaul, N. K.; Dufrene, E.; Francois, C.; Soudani, K.; Ourcival, J. M.; Delpierre, N.

    2015-05-01

    The extent to which wood growth is limited by carbon (C) supply (i.e. source control) or by cambial activity (i.e. sink control) will strongly determine the responses of trees to global changes. Nevertheless, the physiological processes that are responsible for limiting forest growth are still a matter of debate. The aim of this study was to evaluate the key determinants of the annual C allocation to wood along large soil and climate regional gradients over France. The study was conducted for five tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex, Quercus robur and Picea abies). The drivers of stand biomass growth were assessed on both inter-site and inter-annual scales. Our data set comprised field measurements performed at 49 sites (931 site-years) that included biometric measurements and a variety of stand characteristics (e.g. soil water holding capacity, leaf area index). It was complemented with process-based simulations when possible explanatory variables could not be directly measured (e.g. annual and seasonal tree C balance, bioclimatic water stress indices). Specifically, the relative influences of tree C balance (source control), direct environmental control (water and temperature controls of sink activity) and allocation adjustments related to age, past climate conditions, competition intensity and soil nutrient availability on growth were quantified. The inter-site variability in the stand C allocation to wood was predominantly driven by age-related decline. The direct effects of temperature and water stress on sink activity (i.e. effects independent from their effects on the C supply) exerted a strong influence on the annual stand wood growth in all of the species considered, including deciduous temperate species. The lagged effect of the past environmental conditions (e.g. the previous year's water stress and low C uptake) significantly affected the annual C allocation to wood. The C supply

  13. Influence of warming on soil water potential controls seedling mortality in perennial but not annual species in a temperate grassland.

    PubMed

    Hovenden, Mark J; Newton, Paul C D; Wills, Karen E; Janes, Jasmine K; Williams, Amity L; Vander Schoor, Jacqueline K; Nolan, Michaela J

    2008-01-01

    In a water-limited system, the following hypotheses are proposed: warming will increase seedling mortality; elevated atmospheric CO2 will reduce seedling mortality by reducing transpiration, thereby increasing soil water availability; and longevity (i.e. whether a species is annual or perennial) will affect the response of a species to global changes. Here, these three hypotheses are tested by assessing the impact of elevated CO2 (550 micromol mol(-1) and warming (+2 degrees C) on seedling emergence, survivorship and establishment in an Australian temperate grassland from autumn 2004 to autumn 2007. Warming impacts on seedling survivorship were dependent upon species longevity. Warming reduced seedling survivorship of perennials through its effects on soil water potential but the seedling survivorship of annuals was reduced to a greater extent than could be accounted for by treatment effects on soil water potential. Elevated CO2 did not significantly affect seedling survivorship in annuals or perennials. These results show that warming will alter recruitment of perennial species by changing soil water potential but will reduce recruitment of annual species independent of any effects on soil moisture. The results also show that exposure to elevated CO2 does not make seedlings more resistant to dry soils.

  14. Limit of metastability for liquid and vapor phases of water.

    PubMed

    Cho, Woo Jong; Kim, Jaegil; Lee, Joonho; Keyes, Thomas; Straub, John E; Kim, Kwang S

    2014-04-18

    We report the limits of superheating of water and supercooling of vapor from Monte Carlo simulations using microscopic models with configurational enthalpy as the order parameter. The superheating limit is well reproduced. The vapor is predicted to undergo spinodal decomposition at a temperature of Tspvap=46±10 °C (0 °C≪Tspvap≪100 °C) under 1 atm. The water-water network begins to form at the supercooling limit of the vapor. Three-dimensional water-water and cavity-cavity unbroken networks are interwoven at critically superheated liquid water; if either network breaks, the metastable state changes to liquid or vapor.

  15. Snowmelt runoff modeling: Limitations and potential for mitigating water disputes

    NASA Astrophysics Data System (ADS)

    Kult, Jonathan; Choi, Woonsup; Keuser, Anke

    2012-04-01

    SummaryConceptual snowmelt runoff models have proven useful for estimating discharge from remote mountain basins including those spanning the various ranges of the Himalaya. Such models can provide water resource managers with fairly accurate predictions of water availability for operational purposes (e.g. irrigation and hydropower). However, these models have limited ability to address characteristic components of water disputes such as diversions, storage and withholding. Contemporary disputes between India and Pakistan surrounding the snowmelt-derived water resources of the Upper Indus Basin highlight the need for improved water balance accounting methods. We present a research agenda focused on providing refined hydrological contributions to water dispute mitigation efforts.

  16. Peak water limits to freshwater withdrawal and use.

    PubMed

    Gleick, Peter H; Palaniappan, Meena

    2010-06-22

    Freshwater resources are fundamental for maintaining human health, agricultural production, economic activity as well as critical ecosystem functions. As populations and economies grow, new constraints on water resources are appearing, raising questions about limits to water availability. Such resource questions are not new. The specter of "peak oil"--a peaking and then decline in oil production--has long been predicted and debated. We present here a detailed assessment and definition of three concepts of "peak water": peak renewable water, peak nonrenewable water, and peak ecological water. These concepts can help hydrologists, water managers, policy makers, and the public understand and manage different water systems more effectively and sustainably. Peak renewable water applies where flow constraints limit total water availability over time. Peak nonrenewable water is observable in groundwater systems where production rates substantially exceed natural recharge rates and where overpumping or contamination leads to a peak of production followed by a decline, similar to more traditional peak-oil curves. Peak "ecological" water is defined as the point beyond which the total costs of ecological disruptions and damages exceed the total value provided by human use of that water. Despite uncertainties in quantifying many of these costs and benefits in consistent ways, more and more watersheds appear to have already passed the point of peak water. Applying these concepts can help shift the way freshwater resources are managed toward more productive, equitable, efficient, and sustainable use.

  17. Options for complying with water quality-based metal limitations

    SciTech Connect

    Thibodeau, J.

    1996-12-31

    During the past six years, most states have promulgated water quality regulations which contain numerical aquatic life standards for heavy metals. In addition, the Environmental Protection Agency (EPA) promulgated national water quality standards in 1992 which also include numerical aquatic life criteria for heavy metals. Numerous wastewater discharge permits have been issued by the states and EPA to industrial facilities which include low microgram per liter heavy metal limitations. In many instances, the limitations are below detection limits or treatability limits using state-of-the-art analytical methods or treatment technologies. This paper will discuss options for conducting studies, including the use of water-effect ratios, metal partitioning coefficients, and recalculation procedures to develop site-specific metals criteria and higher permit limitations. The installation of expensive metal treatment systems to remove trace metals may be avoided if higher permit limits are indicated by the site-specific studies. 11 refs.

  18. Peak water limits to freshwater withdrawal and use

    PubMed Central

    Gleick, Peter H.; Palaniappan, Meena

    2010-01-01

    Freshwater resources are fundamental for maintaining human health, agricultural production, economic activity as well as critical ecosystem functions. As populations and economies grow, new constraints on water resources are appearing, raising questions about limits to water availability. Such resource questions are not new. The specter of “peak oil”—a peaking and then decline in oil production—has long been predicted and debated. We present here a detailed assessment and definition of three concepts of “peak water”: peak renewable water, peak nonrenewable water, and peak ecological water. These concepts can help hydrologists, water managers, policy makers, and the public understand and manage different water systems more effectively and sustainably. Peak renewable water applies where flow constraints limit total water availability over time. Peak nonrenewable water is observable in groundwater systems where production rates substantially exceed natural recharge rates and where overpumping or contamination leads to a peak of production followed by a decline, similar to more traditional peak-oil curves. Peak “ecological” water is defined as the point beyond which the total costs of ecological disruptions and damages exceed the total value provided by human use of that water. Despite uncertainties in quantifying many of these costs and benefits in consistent ways, more and more watersheds appear to have already passed the point of peak water. Applying these concepts can help shift the way freshwater resources are managed toward more productive, equitable, efficient, and sustainable use. PMID:20498082

  19. The contribution of limited-resource countries to the American Society of Clinical Oncology annual meetings.

    PubMed

    Masmoudi, Amine

    2009-10-01

    Limited-resource countries (LRCs) are underrepresented in biomedical research, and data with respect to oncology are lacking. The aim of the present study was to assess the participation of LRCs in the American Society of Clinical Oncology (ASCO) annual meetings. We analyzed the characteristics of abstracts originating from LRCs presented at the 2005-2007 ASCO meetings. We used a logistic regression model to identify country characteristics associated with contributions to the meetings. Eight percent of abstracts were generated by authors from LRCs. Abstracts from LRCs, compared with abstracts originating from high-income countries (HICs), were less commonly scheduled for oral and poster presentations (1.4% and 26.8% vs 8.8% and 52.8%, respectively; P < 0.001), and were less likely to report industry-provided funding (2.0% vs 12.7%; P < 0.001). However, the presentation type and the rate of reporting industry funding did not significantly differ between HIC abstracts and LRC abstracts involving one or more coauthors from HICs. In multivariate analysis, ASCO-related characteristics, but not geoeconomic parameters, were significantly predictive of country participation in the meetings. These data show that the contribution of LRCs to ASCO annual meetings is very low. Although abstracts originating from LRCs involving authors from HICs were associated with a higher-impact type of presentation, their relevance to the cancer care concerns of LRCs remains to be ascertained.

  20. 50 CFR 648.53 - Acceptable biological catch (ABC), annual catch limits (ACL), annual catch targets (ACT), DAS...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... divided as sub-ACLs between limited access vessels, limited access vessels that are fishing under a LAGC... adjustment. (i) The limited access fishery sub-ACLs for fishing years 2014 and 2015 are: (A) 2014: 18,885 mt...). (i) The ACLs for fishing years 2014 and 2015 for LAGC IFQ vessels without a limited access...

  1. 50 CFR 648.53 - Acceptable biological catch (ABC), annual catch limits (ACL), annual catch targets (ACT), DAS...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... divided as sub-ACLs between limited access vessels, limited access vessels that are fishing under a LAGC... adjustment. (i) The limited access fishery sub-ACLs for fishing years 2013 and 2014 are: (A) 2013: 19,093 mt... paragraph (a). (i) The ACLs for fishing years 2013 and 2014 for LAGC IFQ vessels without a limited...

  2. Annual safe groundwater yield in a semiarid basin using combination of water balance equation and water table fluctuation

    NASA Astrophysics Data System (ADS)

    Rezaei, Abolfazl; Mohammadi, Zargham

    2017-10-01

    The safe groundwater yield plays a major role in the appropriate management of groundwater systems, particularly in (semi-)arid areas like Iran. This study incorporates both the water balance equation and the water table fluctuation to estimate the annual safe yield of the unconfined aquifer in the eastern part of the Kaftar Lake, an Iranian semiarid region. Firstly, the water balance year 2002-03, owing same water table elevation at the beginning and year-end, was chosen from the monthly representative groundwater hydrograph of the aquifer to be taken into account as a basic water year for determining the safe yield. Then the ratio of the total groundwater pumping to the annual groundwater recharge in the selected water balance year together with the quantity of total recharge occurred in the wet period (October to May) of the year of interest were applied to evaluate the annual safe yield at the initiation of the dry period (June to September) of the year of interest. Knowing the annual safe groundwater withdrawal rate at the initiation of each dry period could be helpful to decision makers in managing groundwater resources conservation. Analysis results indicate that to develop a safe management strategy in the aquifer; the ratio of the annual groundwater withdrawal to the annually recharged volume should not exceed 0.69. In the water year 2003-04 where the ratio is equal to 0.52, the water table raised up (about 0.48 m) while the groundwater level significantly declined (about 1.54 m) over the water year 2007-08 where the ratio of the annual groundwater withdrawal to the annually recharged volume (i.e., 2.76) is larger than 0.69.

  3. Links Between Flood Frequency and Annual Water Balance Behaviors: A Basis for Similarity and Regionalization

    SciTech Connect

    Guo, Jiali; Li, Hongyi; Leung, Lai-Yung R.; Guo, Shenglian; Liu, Pan; Sivapalan, Murugesu

    2014-03-28

    This paper presents the results of a data based comparative study of several hundred catchments across continental United States belonging to the MOPEX dataset, which systematically explored the connection between the flood frequency curve and measures of mean annual water balance. Two different measures of mean annual water balance are used: (i) a climatic aridity index, AI, which is a measure of the competition between water and energy availability at the annual scale; and, (ii) baseflow index, BFI, the ratio of slow runoff to total runoff also at the annual time scale, reflecting the role of geology, soils, topography and vegetation. The data analyses showed that the aridity index, AI, has a first order control on both the mean and Cv of annual maximum floods. While mean annual flood decreases with increasing aridity, Cv increases with increasing aridity. BFI appeared to be a second order control on the magnitude and shape of the flood frequency curve. Higher BFI, meaning more subsurface flow and less surface flow leads to a decrease of mean annual flood whereas lower BFI leads to accumulation of soil moisture and increased flood magnitudes that arise from many events acting together. The results presented in this paper provide innovative means to delineate homogeneous regions within which the flood frequency curves can be assumed to be functionally similar. At another level, understanding the connection between annual water balance and flood frequency will be another building block towards developing comprehensive understanding of catchment runoff behavior in a holistic way.

  4. Phosphorus limitation on bacterial regrowth in drinking water.

    PubMed

    Sang, Jun-qiang; Zhang, Xi-hui; Yu, Guo-zhong; Wang, Zhan-sheng

    2003-11-01

    Assimilable organic carbon (AOC) test and bacterial regrowth potential (BRP) analysis were used to investigate the effect of phosphorus on bacterial regrowth in the drinking water that was made from some raw water taken from a reservoir located in northern China. It was shown that AOC of the drinking water samples increased by 43.9%-59.6% and BRP increased by 100%-235% when 50 microg/L PO4(3-)-P(as NaH2 PO4) was added alone to the drinking water samples. This result was clear evidence of phosphorus limitation on bacteria regrowth in the drinking water. This investigation indicated the importance of phosphorus in ensuring biological stability of drinking water and offered a novel possible option to restrict microbial regrowth in drinking water distribution system by applying appropriate technologies to remove phosphorus efficiently from drinking water in China.

  5. Ecological optimality in water-limited natural soil-vegetation systems. I - Theory and hypothesis

    NASA Technical Reports Server (NTRS)

    Eagleson, P. S.

    1982-01-01

    The solution space of an approximate statistical-dynamic model of the average annual water balance is explored with respect to the hydrologic parameters of both soil and vegetation. Within the accuracy of this model it is shown that water-limited natural vegetation systems are in stable equilibrium with their climatic and pedologic environments when the canopy density and species act to minimize average water demand stress. Theory shows a climatic limit to this equilibrium above which it is hypothesized that ecological pressure is toward maximization of biomass productivity. It is further hypothesized that natural soil-vegetation systems will develop gradually and synergistically, through vegetation-induced changes in soil structure, toward a set of hydraulic soil properties for which the minimum stress canopy density of a given species is maximum in a given climate. Using these hypotheses, only the soil effective porosity need be known to determine the optimum soil and vegetation parameters in a given climate.

  6. Quantifying crop water stress factors from soil water measurements in a limited irrigation experiment

    USDA-ARS?s Scientific Manuscript database

    Quantifying crop water stress factors from soil water measurements in a limited irrigation experiment. A correct simulation of crop responses to water stress is essential for a system model. In this study, we investigated three methods of quantifying water deficit stresses based on soil water meas...

  7. Effects of rainfall seasonality and soil moisture capacity on mean annual water balance for Australian catchments

    USGS Publications Warehouse

    Potter, N.J.; Zhang, L.; Milly, P.C.D.; McMahon, T.A.; Jakeman, A.J.

    2005-01-01

    An important factor controlling catchment-scale water balance is the seasonal variation of climate. The aim of this study is to investigate the effect of the seasonal distributions of water and energy, and their interactions with the soil moisture store, on mean annual water balance in Australia at catchment scales using a stochastic model of soil moisture balance with seasonally varying forcing. The rainfall regime at 262 catchments around Australia was modeled as a Poisson process with the mean storm arrival rate and the mean storm depth varying throughout the year as cosine curves with annual periods. The soil moisture dynamics were represented by use of a single, finite water store having infinite infiltration capacity, and the potential evapotranspiration rate was modeled as an annual cosine curve. The mean annual water budget was calculated numerically using a Monte Carlo simulation. The model predicted that for a given level of climatic aridity the ratio of mean annual evapotranspiration to rainfall was larger where the potential evapotranspiration and rainfall were in phase, that is, in summer-dominant rainfall catchments, than where they were out of phase. The observed mean annual evapotranspiration ratios have opposite results. As a result, estimates of mean annual evapotranspiration from the model compared poorly with observational data. Because the inclusion of seasonally varying forcing alone was not sufficient to explain variability in the mean annual water balance, other catchment properties may play a role. Further analysis showed that the water balance was highly sensitive to the catchment-scale soil moisture capacity. Calibrations of this parameter indicated that infiltration-excess runoff might be an important process, especially for the summer-dominant rainfall catchments; most similar studies have shown that modeling of infiltration-excess runoff is not required at the mean annual timescale. Copyright 2005 by the American Geophysical Union.

  8. Tillage Requirments for integrating winter-annual grazing in peanut production: Plant water status and productivity

    USDA-ARS?s Scientific Manuscript database

    The use of crop rotation systems involving winter-annual grazing can help peanut (Arachis hypogaea L.) producers increase profitability, although winter-annual grazing could result in excessive soil compaction, which can severely limit yields. We conducted a 3-yr field study on a Dothan loamy sand i...

  9. Evaluation of high yielding soybean germplasm under water limitation.

    PubMed

    Prince, Silvas J; Murphy, Mackensie; Mutava, Raymond N; Zhang, Zhengzhi; Nguyen, Na; Kim, Yoon Ha; Pathan, Safiullah M; Shannon, Grover J; Valliyodan, Babu; Nguyen, Henry T

    2016-05-01

    Limited information is available for soybean root traits and their plasticity under drought stress. To date, no studies have focused on examining diverse soybean germplasm for regulation of shoot and root response under water limited conditions across varying soil types. In this study, 17 genetically diverse soybean germplasm lines were selected to study root response to water limited conditions in clay (trial 1) and sandy soil (trial 2) in two target environments. Physiological data on shoot traits was measured at multiple crop stages ranging from early vegetative to pod filling. The phenotypic root traits, and biomass accumulation data are collected at pod filling stage. In trial 1, the number of lateral roots and forks were positively correlated with plot yield under water limitation and in trial 2, lateral root thickness was positively correlated with the hill plot yield. Plant Introduction (PI) 578477A and 088444 were found to have higher later root number and forks in clay soil with higher yield under water limitation. In sandy soil, PI458020 was found to have a thicker lateral root system and higher yield under water limitation. The genotypes identified in this study could be used to enhance drought tolerance of elite soybean cultivars through improved root traits specific to target environments. © 2015 Institute of Botany, Chinese Academy of Sciences.

  10. 50 CFR 648.53 - Acceptable biological catch (ABC), annual catch limits (ACL), annual catch targets (ACT), DAS...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... divided as sub-ACLs between limited access vessels, limited access vessels that are fishing under a... limited access fishery sub-ACLs for fishing years 2011 through 2013 are: (A) 2011: 24,954 mt. (B) 2012: 26... catch, observer set-aside, and research set-aside, as specified in this paragraph (a). The LAGC ACLs...

  11. Assessment of Crop Water Requirement Methods for Annual Agricultural Water Allocation Planning

    NASA Astrophysics Data System (ADS)

    Aghdasi, F.; Sharifi, M. A.; van der Tol, C.

    2010-05-01

    The potential use of remote sensing in water resource and in particular in irrigation management has been widely acknowledged. However, in reality, operational applications of remote sensing in irrigation management are few. In this study, the applicability of the main available remote sensing based techniques of irrigation management is evaluated in a pilot area in Iran. The evaluated techniques include so called Crop Water Requirement "CWR" methods for the planning of annual water allocation in irrigated agriculture. A total of 40 years of historical weather data were classified into wet, normal, and dry years using a Standardised Precipitation Index (SPI). For each of these three classes the average CWR was calculated. Next, by applying Markov Chain Process to the time series of precipitation, the expected CWR for the forthcoming planning year was estimated. Using proper interpolation techniques the expected CWR at each station was converted to CWR map of the area, which was then used for annual water allocation planning. To estimate the crop water requirement, methods developed for the DEMETER project (DEMonstration of Earth observation Technologies in Routine irrigation advisory services) and Surface Energy Balance System "SEBS" algorithm were used, and their results were compared with conventional methods, including FAO-56 and lysimeter data amongst others. Use was made of both ASTER and MODIS images to determine crop water requirement at local and regional scales. Four methods of estimating crop coefficients were used: DEMETER Kc-NDVI, DEMETER Kc-analytical, FAO-56 and SEBS algorithm. Results showed that DEMETER (analytical approach) and FAO methods with lowest RMSE are more suitable methods for determination of crop coefficient than SEBS, which gives actual rather than potential evapotranspiration. The use of ASTER and MODIS images did not result in significantly different crop coefficients in the pilot area for the DEMETER analytical approach (α=0

  12. Structural diversity of water-limited savanna and ecosystem response to climatological variability

    NASA Astrophysics Data System (ADS)

    Nosshi, M. I.; Brunsell, N. A.

    2016-12-01

    Determining the sensitivity of ecosystem response to environmental variability is fundamental to understand the capacity of ecosystems to resist and recover from change. Despite limitations to infer about biotic mechanisms, remote sensing has the advantage of high temporal resolution, over long records, to address fundamental challenges in ecology in an environmental context. The degree of structural diversity in water-limited savanna changes across a climatological gradient over the sand covered area in interior southern Africa, between 29° S to the equator and 14° E to 28° E. To determine the coupling between structural diversity and ecosystem function in water-limited ecosystems, we use a 15-year record of daily precipitation, and satellite data for Normalized Difference Vegetation Index (NDVI), matching the same time period (2001-2015), along the Kalahari sand sheet. Savanna ecosystems show a varied temporal sensitivity to environmental fluctuation going from 200 mm to 750 mm of mean annual precipitation. Increasing grass cover results in higher sensitivity to intra-annual dynamics, while an increased woody cover reflects purely annual patterns. Lagged correlations suggest a similar sensitivity at the extreme ends of the gradient, but highest in the middle, between 400 mm and 450 mm of mean annual precipitation. The vegetation in this region, described as a wooded grassland, has contributions to net primary productivity more equally shared by trees and grasses. In particular, the role of rainfall seasonality, magnitude, and frequency is examined in the different savanna, against different indices of ecosystem stability. Finally, using the savanna example to better understand trade-offs, such as how resistance versus recovery, and similarly, stress avoidance versus resource use optimization under a gradient of conditions, highlights the importance of structural diversity in determining ecosystem response to environmental variability.

  13. Feasibility of potable water generators to meet vessel numeric ballast water discharge limits.

    PubMed

    Albert, Ryan J; Viveiros, Edward; Falatko, Debra S; Tamburri, Mario N

    2017-07-15

    Ballast water is taken on-board vessels into ballast water tanks to maintain vessel draft, buoyancy, and stability. Unmanaged ballast water contains aquatic organisms that, when transported and discharged to non-native waters, may establish as invasive species. Technologies capable of achieving regulatory limits designed to decrease the likelihood of invasion include onboard ballast water management systems. However, to date, the treatment development and manufacturing marketplace is limited to large vessels with substantial ballast requirements. For smaller vessels or vessels with reduced ballast requirements, we evaluated the feasibility of meeting the discharge limits by generating ballast water using onboard potable water generators. Case studies and parametric analyses demonstrated the architectural feasibility of installing potable water generators onboard actual vessels with minimal impacts for most vessel types evaluated. Furthermore, land-based testing of a potable water generator demonstrated capability to meet current numeric discharge limits for living organisms in all size classes. Published by Elsevier Ltd.

  14. DOE Annual Progress Report: Water Needs and Constraints for Hydrogen Pathways

    SciTech Connect

    Simon, A; Daily, W

    2009-07-02

    Water is a critical feedstock in the production of hydrogen. In fact, water and many of the energy transformations upon which society depends are inextricably linked. Approximately 39% of freshwater withdrawals are used for cooling of power plants, and another 8% are used in industry and mining (including oil and gas extraction and refining). Major changes in the energy infrastructure (as envisioned in a transformation to a hydrogen economy) will necessarily result in changes to the water infrastructure. Depending on the manner in which a hydrogen economy evolves, these changes could be large or small, detrimental or benign. Water is used as a chemical feedstock for hydrogen production and as a coolant for the production process. Process and cooling water must meet minimum quality specifications (limits on mineral and organic contaminants) at both the inlet to the process and at the point of discharge. If these specifications are not met, then the water must be treated, which involves extra expenditure on equipment and energy. There are multiple options for water treatment and cooling systems, each of which has a different profile of equipment cost and operational requirements. The engineering decisions that are made when building out the hydrogen infrastructure will play an important role in the cost of producing hydrogen, and those decisions will be influenced by the regional and national policies that help to manage water resources. In order to evaluate the impacts of water on hydrogen production and of a hydrogen economy on water resources, this project takes a narrowly-scoped lifecycle analysis approach. We begin with a process model of hydrogen production and calculate the process water, cooling, electricity and energy feedstock demands. We expand beyond the production process itself by analyzing the details of the cooling system and water treatment system. At a regional scale, we also consider the water use associated with the electricity and fuel that feed

  15. Constraining Annual Water Balance Estimates with Basin-Scale Observations from the Airborne Snow Observatory during the Current Californian Drought

    NASA Astrophysics Data System (ADS)

    Bormann, K.; Painter, T. H.; Marks, D. G.; Hedrick, A. R.; Deems, J. S.; Patterson, V.; McGurk, B. J.

    2015-12-01

    One of the great unknowns in mountain hydrology is how much water is stored within a seasonal snowpack at the basin scale. Quantifying mountain water resources is critical for assisting with water resource management, but has proven elusive due to high spatial and temporal variability of mountain snow cover, complex terrain, accessibility constraints and limited in-situ networks. The Airborne Snow Observatory (ASO, aso.jpl.nasa.gov) uses coupled airborne LiDAR and spectrometer instruments for high resolution snow depth retrievals which are used to derive unprecedented basin-wide estimates of snow water mass (snow water equivalent, SWE). ASO has been operational over key basins in the Sierra Nevada Mountains in California since 2013. Each operational year has been very dry, with precipitation in 2013 at 75% of average, 2014 at 50% of average and 2015 - the lowest snow year on record for the region. With vastly improved estimates of the snowpack water content from ASO, we can now for the first time conduct observation-based mass balance accounting of surface water in snow-dominated basins, and reconcile these estimates with observed reservoir inflows. In this study we use ASO SWE data to constrain mass balance accounting of basin annual water storages to quantify the water contained within the snowpack above the Hetch Hetchy water supply reservoir (Tuolumne River basin, California). The analysis compares and contrasts annual snow water volumes from observed reservoir inflows, snow water volume estimates from ASO, a physically based model that simulates the snowpack from meteorological inputs and a semi-distributed hydrological model. The study provides invaluable insight to the overall volume of water contained within a seasonal snowpack during a severe drought and how these quantities are simulated in our modelling systems. We envisage that this research will be of great interest to snowpack modellers, hydrologists, dam operators and water managers worldwide.

  16. Limits of state activity in the interstate water market

    SciTech Connect

    Rodgers, A.B.

    1986-01-01

    In an effort to ensure future water supplies, many western states are becoming participants in the market for water. As market participants, states gain a proprietary interest in their water resources which more effectively secures their right to the water than mere regulation or claims of ownership under the public trust doctrine. As the author points out, however, the constitution imposes numerous limitations on state water market activity. The privileges and immunities clause, the commerce clause, the property clause, as well as the equal protection clause of the fourteenth amendment, all influence the manner in which states may behave. Most significantly, the author explains, these clauses prevent states from using their power as water market participants as a disguise for economic protectionism.

  17. Extreme rainfall events can alter inter-annual biomass responses to water and N enrichment

    NASA Astrophysics Data System (ADS)

    Kong, D. L.; Lü, X. T.; Jiang, L. L.; Wu, H. F.; Miao, Y.; Kardol, P.

    2013-12-01

    Water availability has profound effects on plant growth and productivity in temperate and semiarid grasslands. However, it remains unclear how variation of inter-annual precipitation by extreme rainfall events will alter the aboveground and belowground responses of plants, and how these responses may be contingent on N availability. In this study, we examined the interactive effects of inter-annual precipitation variation and N addition on aboveground and live fine root biomass of a semiarid grassland in northern China for two consecutive years (2007 and 2008). Inter-annual variation in precipitation resulting mainly from the occurrence of extreme rainfall events in 2008 significantly affected above- and belowground plant biomass responses to water addition. In addition, variation of inter-annual precipitation by this extreme rainfall event suppressed plant responses to nitrogen addition and reduced the interaction effects between water and nitrogen addition. These effects of inter-annual precipitation fluctuation could be attributed to the negative influence of the extreme rainfall event on soil N and water availability, ultimately reducing plant rainfall use efficiency and nitrogen use efficiency. In conclusion, our results suggest ecosystem responses to water and N enrichment could be altered by inter-annual variation of precipitation regime caused by the naturally occurring extreme rainfall events.

  18. Annual water-resources review, White Sands Missile Range: 1971

    USGS Publications Warehouse

    Cruz, R.R.

    1972-01-01

    This report presents water-resource information that was collected at White Sands Missile Range during 1971 and early 1972 by personnel of the U.S. Geological Survey, Water Resources Division. Data on ground-water pumpage and resulting water-level fluctuation, chemical quality, percipitation, and surface-water runoff are summarized in the report. The data were obtained as a result of the continuing water-resources basic-data collection program sponsored by the Facilities Engineering Directorate, White Sands Missile Range.

  19. Annual estimates of water and solute export from 42 tributaries to the Yukon River

    USGS Publications Warehouse

    Frederick Zanden,; Suzanne P. Anderson,; Striegl, Robert G.

    2012-01-01

    Annual export of 11 major and trace solutes for the Yukon River is found to be accurately determined based on summing 42 tributary contributions. These findings provide the first published estimates of tributary specific distribution of solutes within the Yukon River basin. First, we show that annual discharge of the Yukon River can be computed by summing calculated annual discharges from 42 tributaries. Annual discharge for the tributaries is calculated from the basin area and average annual precipitation over that area using a previously published regional regression equation. Based on tributary inputs, we estimate an average annual discharge for the Yukon River of 210 km3 year–1. This value is within 1% of the average measured annual discharge at the U.S. Geological Survey gaging station near the river terminus at Pilot Station, AK, for water years 2001 through 2005. Next, annual loads for 11 solutes are determined by combining annual discharge with point measurements of solute concentrations in tributary river water. Based on the sum of solutes in tributary water, we find that the Yukon River discharges approximately 33 million metric tons of dissolved solids each year at Pilot Station. Discharged solutes are dominated by cations calcium and magnesium (5.65 × 109 and 1.42 × 109 g year–1) and anions bicarbonate and sulphate (17.3 × 109 and 5.40 × 109 g year–1). These loads compare well with loads calculated independently at the three continuous gaging stations along the Yukon River. These findings show how annual solute yields vary throughout a major subarctic river basin and that accurate estimates of total river export can be determined from calculated tributary contributions.

  20. Climate change impact on the annual water balance in the northwest Florida coastal

    NASA Astrophysics Data System (ADS)

    Alizad, K.; Wang, D.; Alimohammadi, N.; Hagen, S. C.

    2012-12-01

    As the largest tributary to the Apalachicola River, the Chipola River originates in southern Alabama, flows through Florida Panhandle and ended to Gulf of Mexico. The Chipola watershed is located in an intermediate climate environment with aridity index around one. Watershed provides habitat for a number of threatened and endangered animal and plant species. However, climate change affects hydrologic cycle of Chipola River watershed at various temporal and spatial scales. Studying the effects of climate variations is of great importance for water and environmental management purposes in this catchment. This research is mainly focuses on assessing climate change impact on the partitioning pattern of rainfall from mean annual to inter-annual and to seasonal scales. At the mean annual scale, rainfall is partitioned into runoff and evaporation assuming negligible water storage changes. Mean annual runoff is controlled by both mean annual precipitation and potential evaporation. Changes in long term mean runoff caused by variations of long term mean precipitation and potential evaporation will be evaluated based on Budyko hypothesis. At the annual scale, rainfall is partitioned into runoff, evaporation, and storage change. Inter-annual variability of runoff and evaporation are mainly affected by the changes of mean annual climate variables as well as their inter-annual variability. In order to model and evaluate each component of water balance at the annual scale, parsimonious but reliable models, are developed. Budyko hypothesis on the existing balance between available water and energy supply is reconsidered and redefined for the sub-annual time scale and reconstructed accordingly in order to accurately model seasonal hydrologic balance of the catchment. Models are built in the seasonal time frame with a focus on the role of storage change in water cycle. Then for Chipola catchment, models are parameterized based on a sufficient time span of historical data and the

  1. 25 CFR 171.710 - Can I receive irrigation water if I am granted an Annual Assessment Waiver?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Can I receive irrigation water if I am granted an Annual... AND WATER IRRIGATION OPERATION AND MAINTENANCE Non-Assessment Status § 171.710 Can I receive irrigation water if I am granted an Annual Assessment Waiver? No. Water will not be delivered in any quantity...

  2. 25 CFR 171.710 - Can I receive irrigation water if I am granted an Annual Assessment Waiver?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Can I receive irrigation water if I am granted an Annual... AND WATER IRRIGATION OPERATION AND MAINTENANCE Non-Assessment Status § 171.710 Can I receive irrigation water if I am granted an Annual Assessment Waiver? No. Water will not be delivered in any quantity...

  3. 25 CFR 171.710 - Can I receive irrigation water if I am granted an Annual Assessment Waiver?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Can I receive irrigation water if I am granted an Annual... AND WATER IRRIGATION OPERATION AND MAINTENANCE Non-Assessment Status § 171.710 Can I receive irrigation water if I am granted an Annual Assessment Waiver? No. Water will not be delivered in any quantity...

  4. 25 CFR 171.710 - Can I receive irrigation water if I am granted an Annual Assessment Waiver?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Can I receive irrigation water if I am granted an Annual... AND WATER IRRIGATION OPERATION AND MAINTENANCE Non-Assessment Status § 171.710 Can I receive irrigation water if I am granted an Annual Assessment Waiver? No. Water will not be delivered in any quantity...

  5. Evaluation of annual corrosion tests for aggressive water

    NASA Astrophysics Data System (ADS)

    Dubová, V.; Ilavský, J.; Barloková, D.

    2011-12-01

    Internal corrosion has a significant effect on the useful life of pipes, the hydraulic conditions of a distribution system and the quality of the water transported. All water is corrosive under some conditions, and the level of this corrosion depends on the physical and chemical properties of the water and properties of the pipe material. Galvanic treatment is an innovation for protecting against corrosion, and this method is also suitable for removal of water stone too. This method consists of the electrogalvanic principle, which is generated by the flowing of water between a zinc anode and the cupro-alloy cover of a column. This article presents experimental corrosion tests at water resource Pernek (This water resource-well marked as HL-1 is close to the Pernek of village), where the device is operating based on this principle.

  6. Shift of annual water balance in the Budyko space for a catchment with groundwater dependent evapotranspiration

    NASA Astrophysics Data System (ADS)

    Wang, X.-S.; Zhou, Y.

    2015-11-01

    Empirical equations have been formulated for the general relationship between the evapotranspiration ratio (F) and the aridity index (φ) in the Budyko framework. Though it is normally applied for mean annual behaviors, the Budyko hypothesis has been directly adopted to analyze the interannual change in water balance. However, there are reported cases where the annual evapotranspiration ratio is larger than 1.0 (F > 1). This study reveals the effects of groundwater dependent evapotranspiration in triggering such abnormal shift of annual water balance in the Budyko space. A widely used monthly hydrological model, the ABCD model, is modified to incorporate the groundwater dependent evapotranspiration in the zone with shallow water table and delayed groundwater recharge in the zone with deep water table. This model is applied in the Hailiutu River catchment in China. Results show that the variations in the annual evapotranspiration ratio with aridity index do not satisfy the traditional Budyko hypothesis. The shift of the annual water balance in the Budyko space depends on the proportion of shallow water table area, intensity of groundwater dependent evapotranspiration, and the normal Budyko-type trend of F in the deep groundwater zone. Excess evapotranspiration (F > 1) could occur in extreme dry years, which is enhanced by groundwater-dependent evapotranspiration. Use of groundwater for irrigation may increase the frequency of occurrence of the F > 1 cases.

  7. Impact of an annual dollar limit or "cap" on prescription drug benefits for Medicare patients.

    PubMed

    Tseng, Chien-Wen; Brook, Robert H; Keeler, Emmett; Mangione, Carol M

    2003-07-09

    Annual dollar limits, or "caps," on drug benefits are common in Medicare managed care (Medicare + Choice) and have been part of several proposals for a national Medicare drug benefit. To determine how cap levels affect the percentage of patients exceeding the cap and their out-of-pocket drug costs and to identify the medications that contribute most to prescription costs. Cross-sectional analysis of 2001 pharmacy claims data from a large Medicare + Choice plan in a mature market with caps of 750 dollars to 2000 dollars per year applied to the plan's share of prescription costs. Patients who filled at least 1 prescription in 2001 (n = 438 802). Percentages of patients exceeding caps, identified from prescription claims; out-of-pocket patient costs before exceeding caps, calculated from patients' co-payments; and out-of-pocket patient costs after exceeding caps, estimated from total prescription costs before exceeding the cap. Each unique drug was ranked by total expenditures, which included spending by patients who exceeded caps and by the plan for that drug. A total of 22%, 14%, and 4% of Medicare patients exceeded caps of 750 dollars, 1000 dollars, and 2000 dollars, respectively. Across caps, patients faced a potential 2- to 3-fold increase in median out-of-pocket costs after exceeding caps (179 dollars-305/mo dollars) to continue the same prescription use as before exceeding caps (79-100/mo dollars). For patients who exceeded a cap of 750 dollars, yearly out-of-pocket drug costs ranged from 564 dollars to 4201 dollars (5th-95th percentiles). Fifteen of the 20 medications with the highest total prescription expenditures for patients who exceeded the cap were for chronic conditions. Seven had lower-cost generic versions or a generic medication available in the same treatment class. At lower caps, a substantial proportion of Medicare patients exceeded their annual drug benefit. To continue the same medication use as before exceeding caps, these patients faced

  8. Annual period temperature and salinity signals of surface waters in Prince William Sound, Alaska

    NASA Astrophysics Data System (ADS)

    Okkonen, Stephen R.; Bélanger, Claude

    2008-07-01

    Temperature and salinity measurements acquired during thermosalinograph surveys conducted throughout Prince William Sound (PWS) between March 2006 and January 2008 are used to identify annual period temperature and salinity signals of surface waters. Mean states and annual period changes in oceanic conditions throughout PWS reflect proximity to glaciated watersheds. Mean temperatures are coolest in northern and western PWS and warmest in southeastern PWS. Annual period temperature amplitude is greatest in western PWS. Mean salinities are lowest in northern and western PWS and highest in central and southeastern PWS. Annual period salinity amplitude is greatest in northern and western PWS. These results represent the most spatially comprehensive descriptions to date of annual period temperature and salinity signals in PWS. The results are applicable as benchmarks for validation of numerical PWS circulation models and as a decision support tool for the use of dispersants in the event of an oil spill.

  9. 50 CFR 622.193 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... increase in the respective sector ACLs will be applied. (ii) (e) Black sea bass—(1) Commercial sector. (i... landings for black sea bass, as estimated by the SRD, are projected to reach the recreational ACL specified... harvested, i.e. in state or Federal waters. (ii) The recreational ACL for black sea bass is 876,254 lb (397...

  10. 50 CFR 622.41 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ACL based on a moving multi-year average of landings, as described in the FMP. (c) Other shallow-water....775 million kg) for 2015 and subsequent fishing years. (e) Red grouper—(1) Commercial sector. The IFQ... commercial red grouper. The applicable commercial ACL for red grouper, in gutted weight, for 2012...

  11. Forests in a water limited world under climate change

    Treesearch

    C. Mátyás; G. Sun

    2014-01-01

    The debate on ecological and climatic benefits of planted forests at the sensitive dry edge of the closed forest belt (i.e. at the ‘xeric limits’) is still unresolved. Forests sequester atmospheric carbon dioxide, accumulate biomass, control water erosion and dust storms, reduce river sedimentation, and mitigate small floods. However, planting trees in areas previously...

  12. Alfalfa response to irrigation from limited water supplies

    USDA-ARS?s Scientific Manuscript database

    A five-year field study (2007-2011) of irrigated alfalfa production with a limited water supply was conducted in southwest Kansas with two years of above-average precipitation, one year of average precipitation, and two years of below-average precipitation. The irrigation treatments were designed to...

  13. The SPARC water vapour assessment II: comparison of annual, semi-annual and quasi-biennial variations in stratospheric and lower mesospheric water vapour observed from satellites

    NASA Astrophysics Data System (ADS)

    Lossow, Stefan; Khosrawi, Farahnaz; Nedoluha, Gerald E.; Azam, Faiza; Bramstedt, Klaus; Burrows, John. P.; Dinelli, Bianca M.; Eriksson, Patrick; Espy, Patrick J.; García-Comas, Maya; Gille, John C.; Kiefer, Michael; Noël, Stefan; Raspollini, Piera; Read, William G.; Rosenlof, Karen H.; Rozanov, Alexei; Sioris, Christopher E.; Stiller, Gabriele P.; Walker, Kaley A.; Weigel, Katja

    2017-03-01

    In the framework of the second SPARC (Stratosphere-troposphere Processes And their Role in Climate) water vapour assessment (WAVAS-II), the amplitudes and phases of the annual, semi-annual and quasi-biennial variation in stratospheric and lower mesospheric water were compared using 30 data sets from 13 different satellite instruments. These comparisons aimed to provide a comprehensive overview of the typical uncertainties in the observational database which can be considered in subsequent observational and modelling studies. For the amplitudes, a good agreement of their latitude and altitude distribution was found. Quantitatively there were differences in particular at high latitudes, close to the tropopause and in the lower mesosphere. In these regions, the standard deviation over all data sets typically exceeded 0.2 ppmv for the annual variation and 0.1 ppmv for the semi-annual and quasi-biennial variation. For the phase, larger differences between the data sets were found in the lower mesosphere. Generally the smallest phase uncertainties can be observed in regions where the amplitude of the variability is large. The standard deviations of the phases for all data sets were typically smaller than a month for the annual and semi-annual variation and smaller than 5 months for the quasi-biennial variation. The amplitude and phase differences among the data sets are caused by a combination of factors. In general, differences in the temporal variation of systematic errors and in the observational sampling play a dominant role. In addition, differences in the vertical resolution of the data, the considered time periods and influences of clouds, aerosols as well as non-local thermodynamic equilibrium (NLTE) effects cause differences between the individual data sets.

  14. Water Science and Technology Board. Annual report 1991

    SciTech Connect

    Not Available

    1995-01-01

    This report summarizes the activities of the Water Science and Technology Board during 1991. The WSTB is intended to be a dynamic forum, a mechanism by which the broad community of water science, technology, and policy professionals can help assure high-quality national water programs. The principal products of WSTB studies are written reports which cover a wide range of water resources issues of current national concern. A few recent examples are: Restoration of aquatic ecosystems - science, technologies and public policy; Water transfers in the West - efficiency, equity and the environment; Opportunities in the hydrologic sciences; and Ground water models - scientific and regulatory applications. Projects completed, ongoing studies and published reports are described in detail in their respective sections of this report.

  15. Water Science and Technology Board. Annual report 1993-1994

    SciTech Connect

    Not Available

    1995-01-01

    This report summarizes the activities of the Water Science and Technology Board during 1993-1994. The WSTB is intended to be a dynamic forum, a mechanism by which the broad community of water science, technology, and policy professionals can help assure high-quality national water programs. The principal products of WSTB studies are written reports which cover a wide range of water resources issues of current national concern. A few recent examples are: Alternatives for ground water cleanup; Managing wastewater in coastal urban areas; and, Water transfers in the West - efficiency, equity and the environment. Projects completed, ongoing studies and published reports are described in detail in their respective sections of this report.

  16. Water Science and Technology Board. Annual report 1992-1993

    SciTech Connect

    Not Available

    1995-01-01

    This report summarizes the activities of the Water Science and Technology Board during 1992. The WSTB is intended to be a dynamic forum, a mechanism by which the broad community of water science, technology, and policy professionals can help assure high-quality national water programs. The principal products of WSTB studies are written reports which cover a wide range of water resources issues of current national concern. A few recent examples are: Managing wastewater in coastal urban areas; Ground water vulnerability assessment; Water transfers in the West - efficiency, equity and the environment; and Opportunities in the hydrologic sciences. Projects completed, ongoing studies and published reports are described in detail in their respective sections of this report.

  17. 77 FR 10977 - Fisheries of the Northeastern United States; Atlantic Herring Fishery; Sub-Annual Catch Limit...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-24

    ... Northeastern United States; Atlantic Herring Fishery; Sub-Annual Catch Limit (ACL) Harvested for Management... January 1, 2013, when the 2013 sub-ACL for Area 1B becomes available, except when transiting as described in this notice. This action is based on the determination that the revised Atlantic herring...

  18. 5 CFR 630.1110 - Limitation on the amount of annual leave donated by an emergency leave donor.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Limitation on the amount of annual leave donated by an emergency leave donor. 630.1110 Section 630.1110 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS ABSENCE AND LEAVE Emergency Leave Transfer Program § 630.1110...

  19. Global water resources assessment at a sub-annual timescale: Application to climate change impact assessment

    NASA Astrophysics Data System (ADS)

    Yamamoto, T.; Hanasaki, N.; Takahashi, K.; Hijioka, Y.

    2010-12-01

    Several reports have assessed water scarcity globally using the widely accepted withdrawal-to-water resources ratio (hereafter WWR). This index is defined as the ratio of annual withdrawal to the annual renewable water resources (runoff). The index has also been used widely to assess the impact of climate change on global water resources. Here, we ask whether it is appropriate to use the WWR to assess the impact of climate change. Global warming is projected to increase the mean annual runoff in many parts of the world. Therefore, in these regions, the WWR decreases, by definition. However, water scarcity may not always be alleviated in these regions. Global warming is also projected to increase the temporal and spatial variability of precipitation, decrease snowfall, and change the timing of snowmelt. These phenomena may increase the temporal gap between water availability and water demand, which might worsen local water scarcity, even if the mean annual runoff is increased. To assess the impact of climate change on global water resources incorporating subannual time-scale phenomena, this study applies a new water scarcity index, the cumulative withdrawal-to-demand ratio (hereafter CWD). This index is defined as the ratio of the accumulation of daily water withdrawal from local water resources to the accumulation of daily water demand. To estimate daily water withdrawal and water demand, we used the state-of-the-art H08 global water resources model. Our results indicated that global warming increased the mean annual runoff in 52% of the total land area globally. However, in 22% of the area where runoff increased, the CWD showed increased water stress. Those regions included India, northern China, and northern Europe. For India, the increase in water stress was attributed to the seasonal gap between runoff increase and water demand. The increased runoff was concentrated in a few months, while the high water demand months differed and were much longer. For Europe

  20. 50 CFR 622.388 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... accountability measures (AMs). (a) Gulf migratory group king mackerel—(1) Commercial sector. If commercial... king mackerel of zero, unless the best scientific information available determines that a bag limit... through June 1. (b) Atlantic migratory group king mackerel—(1) Commercial sector—(i) If...

  1. 50 CFR 622.388 - Annual catch limits (ACLs), annual catch targets (ACTs), and accountability measures (AMs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... accountability measures (AMs). (a) Gulf migratory group king mackerel—(1) Commercial sector. If commercial... king mackerel of zero, unless the best scientific information available determines that a bag limit... through June 1. (b) Atlantic migratory group king mackerel—(1) Commercial sector—(i) If...

  2. Has water limited our imagination for aridland biogeochemistry?

    PubMed

    Austin, Amy T

    2011-05-01

    The classic ecological paradigm for deserts, that all processes are controlled by water availability, has limited our imagination for exploring other controls on the cycling of carbon and nutrients in aridland ecosystems. This review of recent studies identifies alternative mechanisms that challenge the idea that all soil processes in aridlands are proximately water-limited, and highlights the significance of photodegradation of aboveground litter and the overriding importance of spatial heterogeneity as a modulator of biotic responses to water availability. Aridlands currently occupy >30% of the terrestrial land surface and are expanding. It is therefore critical to incorporate these previously unappreciated mechanisms in our understanding of aridland biogeochemistry to mitigate the effects of desertification and global change.

  3. Multi-tissue analyses reveal limited inter-annual and seasonal variation in mercury exposure in an Antarctic penguin community.

    PubMed

    Brasso, Rebecka L; Polito, Michael J; Emslie, Steven D

    2014-10-01

    Inter-annual variation in tissue mercury concentrations in birds can result from annual changes in the bioavailability of mercury or shifts in dietary composition and/or trophic level. We investigated potential annual variability in mercury dynamics in the Antarctic marine food web using Pygoscelis penguins as biomonitors. Eggshell membrane, chick down, and adult feathers were collected from three species of sympatrically breeding Pygoscelis penguins during the austral summers of 2006/2007-2010/2011. To evaluate the hypothesis that mercury concentrations in penguins exhibit significant inter-annual variation and to determine the potential source of such variation (dietary or environmental), we compared tissue mercury concentrations with trophic levels as indicated by δ(15)N values from all species and tissues. Overall, no inter-annual variation in mercury was observed in adult feathers suggesting that mercury exposure, on an annual scale, was consistent for Pygoscelis penguins. However, when examining tissues that reflected more discrete time periods (chick down and eggshell membrane) relative to adult feathers, we found some evidence of inter-annual variation in mercury exposure during penguins' pre-breeding and chick rearing periods. Evidence of inter-annual variation in penguin trophic level was also limited suggesting that foraging ecology and environmental factors related to the bioavailability of mercury may provide more explanatory power for mercury exposure compared to trophic level alone. Even so, the variable strength of relationships observed between trophic level and tissue mercury concentrations across and within Pygoscelis penguin species suggest that caution is required when selecting appropriate species and tissue combinations for environmental biomonitoring studies in Antarctica.

  4. Century-scale variability in global annual runoff examined using a water balance model

    USGS Publications Warehouse

    McCabe, G.J.; Wolock, D.M.

    2011-01-01

    A monthly water balance model (WB model) is used with CRUTS2.1 monthly temperature and precipitation data to generate time series of monthly runoff for all land areas of the globe for the period 1905 through 2002. Even though annual precipitation accounts for most of the temporal and spatial variability in annual runoff, increases in temperature have had an increasingly negative effect on annual runoff after 1980. Although the effects of increasing temperature on runoff became more apparent after 1980, the relative magnitude of these effects are small compared to the effects of precipitation on global runoff. ?? 2010 Royal Meteorological Society.

  5. Antimicrobial nanomaterials as water disinfectant: applications, limitations and future perspectives.

    PubMed

    Hossain, Fahim; Perales-Perez, Oscar J; Hwang, Sangchul; Román, Félix

    2014-01-01

    Nanotechnology and its application is one of the rapidly developing sciences. As demand of fresh drinking water is increasing, nanotechnology can contribute noticeable development and improvement to water treatment process. Disinfection process is the last and most important step in water and wastewater treatment process. Some nanomaterials can be used as disinfectants due to their antimicrobial properties and reduce the possibility of harmful disinfection by-products (DBPs) formation during traditional disinfection process. A significant number of research efforts is done or going on to understand the mechanisms and enhance the efficiency of nanomaterials as antimicrobial agents, although it will take more time to understand the full potential of nanomaterials in this field. This review paper focuses on inactivation pathways of benign nanomaterials, their possible and probable application and limitations as disinfectants and future opportunities for their application in water cleaning processes.

  6. Effects of Spatial Variability on Annual Average Water Balance

    NASA Astrophysics Data System (ADS)

    Milly, P. C. D.; Eagleson, P. S.

    1987-11-01

    Spatial variability of soil and vegetation causes spatial variability of the water balance. For an area in which the water balance is not affected by lateral water flow, the frequency distributions of storm surface runoff, evapotranspiration, and drainage to groundwater are derivable from distributions of soil hydraulic parameters by means of a point water balance model and local application of the vegetal equilibrium hypothesis. Means and variances of the components of the budget can be found by Monte Carlo simulation or by approximate local expansions. For a fixed set of mean soil parameters, soil spatial variability may induce significant changes in the areal mean water balance, particularly if storm surface runoff occurs. Variability of the pore size distribution index and permeability has a much larger effect than that of effective porosity on the means and variances of water balance variables. The importance of the pore size distribution index implies that the microscopic similarity assumption may underestimate the effects of soil spatial variability. In general, the presence of soil variability reduces the sensitivity of water balance to mean properties. For small levels of soil variability, there exists a unique equivalent homogeneous soil type that reproduces the budget components and the mean soil moisture saturation of an inhomogeneous area.

  7. Beyond annual streamflow reconstructions for the Upper Colorado River Basin: a paleo-water-balance approach

    USGS Publications Warehouse

    Subhrendu Gangopadhyay,; McCabe, Gregory J.; Woodhouse, Connie A.

    2015-01-01

    In this paper, we present a methodology to use annual tree-ring chronologies and a monthly water balance model to generate annual reconstructions of water balance variables (e.g., potential evapotrans- piration (PET), actual evapotranspiration (AET), snow water equivalent (SWE), soil moisture storage (SMS), and runoff (R)). The method involves resampling monthly temperature and precipitation from the instrumental record directed by variability indicated by the paleoclimate record. The generated time series of monthly temperature and precipitation are subsequently used as inputs to a monthly water balance model. The methodology is applied to the Upper Colorado River Basin, and results indicate that the methodology reliably simulates water-year runoff, maximum snow water equivalent, and seasonal soil moisture storage for the instrumental period. As a final application, the methodology is used to produce time series of PET, AET, SWE, SMS, and R for the 1404–1905 period for the Upper Colorado River Basin.

  8. Beyond annual streamflow reconstructions for the Upper Colorado River Basin: A paleo-water-balance approach

    NASA Astrophysics Data System (ADS)

    Gangopadhyay, Subhrendu; McCabe, Gregory J.; Woodhouse, Connie A.

    2015-12-01

    In this paper, we present a methodology to use annual tree-ring chronologies and a monthly water balance model to generate annual reconstructions of water balance variables (e.g., potential evapotranspiration (PET), actual evapotranspiration (AET), snow water equivalent (SWE), soil moisture storage (SMS), and runoff (R)). The method involves resampling monthly temperature and precipitation from the instrumental record directed by variability indicated by the paleoclimate record. The generated time series of monthly temperature and precipitation are subsequently used as inputs to a monthly water balance model. The methodology is applied to the Upper Colorado River Basin, and results indicate that the methodology reliably simulates water-year runoff, maximum snow water equivalent, and seasonal soil moisture storage for the instrumental period. As a final application, the methodology is used to produce time series of PET, AET, SWE, SMS, and R for the 1404-1905 period for the Upper Colorado River Basin.

  9. The strengths and limitations of national water policies for water 'security.' (Invited)

    NASA Astrophysics Data System (ADS)

    Gleick, P. H.

    2013-12-01

    Sustainable water practices and policies must emerge at local, watershed, and national levels. The appropriate scale and type of policy will depend on scientific data and information, economic and institutional factors, and political will. Recent advances in hydroclimatic tools suggest the importance and limitations of national policies for monitoring, assessing, and managing freshwater resources. These tools include remote sensing of key hydroclimatic variables, multi-scale models for integrating hydrology and water management, technologies for enhancing water supply or improving water-use productivity, and theoretical approaches for developing sustainable water policies, including the concepts of 'peak water,' the 'soft path for water,' and integrated water resources management. This talk will address the scientific tools as well as the appropriate policies and strategies at different geographical scales critical for 21st century sustainable water management. The issue of 'zombie' water projects will also be addressed along with their role in national water strategies in the US, China, Africa, and elsewhere.

  10. Water Science and Technology Board annual report, 1990

    SciTech Connect

    Not Available

    1990-12-31

    This report summarizes the activities of the Water Science and Technology Board (WSTB) during 1990, its eighth year of existence. It describes current and recently completed projects, new activities scheduled to begin in 1991, and plans for the future. The WSTB is intended to be a dynamic forum, a mechanism by which the board community of water science, technology, and policy professionals can help assure high-quality national water programs. As such, the Board considers out-reach and communications of much importance.

  11. Water Science and Technology Board annual report, 1990

    SciTech Connect

    Not Available

    1990-01-01

    This report summarizes the activities of the Water Science and Technology Board (WSTB) during 1990, its eighth year of existence. It describes current and recently completed projects, new activities scheduled to begin in 1991, and plans for the future. The WSTB is intended to be a dynamic forum, a mechanism by which the board community of water science, technology, and policy professionals can help assure high-quality national water programs. As such, the Board considers out-reach and communications of much importance.

  12. Revegetation in China’s Loess Plateau is approaching sustainable water resource limits

    NASA Astrophysics Data System (ADS)

    Feng, Xiaoming; Fu, Bojie; Piao, Shilong; Wang, Shuai; Ciais, Philippe; Zeng, Zhenzhong; Lü, Yihe; Zeng, Yuan; Li, Yue; Jiang, Xiaohui; Wu, Bingfang

    2016-11-01

    Revegetation of degraded ecosystems provides opportunities for carbon sequestration and bioenergy production. However, vegetation expansion in water-limited areas creates potentially conflicting demands for water between the ecosystem and humans. Current understanding of these competing demands is still limited. Here, we study the semi-arid Loess Plateau in China, where the `Grain to Green’ large-scale revegetation programme has been in operation since 1999. As expected, we found that the new planting has caused both net primary productivity (NPP) and evapotranspiration (ET) to increase. Also the increase of ET has induced a significant (p < 0.001) decrease in the ratio of river runoff to annual precipitation across hydrological catchments. From currently revegetated areas and human water demand, we estimate a threshold of NPP of 400 +/- 5 g C m-2 yr-1 above which the population will suffer water shortages. NPP in this region is found to be already close to this limit. The threshold of NPP could change by -36% in the worst case of climate drying and high human withdrawals, to +43% in the best case. Our results develop a new conceptual framework to determine the critical carbon sequestration that is sustainable in terms of both ecological and socio-economic resource demands in a coupled anthropogenic-biological system.

  13. Accuracy limit of rigid 3-point water models

    NASA Astrophysics Data System (ADS)

    Izadi, Saeed; Onufriev, Alexey V.

    2016-08-01

    Classical 3-point rigid water models are most widely used due to their computational efficiency. Recently, we introduced a new approach to constructing classical rigid water models [S. Izadi et al., J. Phys. Chem. Lett. 5, 3863 (2014)], which permits a virtually exhaustive search for globally optimal model parameters in the sub-space that is most relevant to the electrostatic properties of the water molecule in liquid phase. Here we apply the approach to develop a 3-point Optimal Point Charge (OPC3) water model. OPC3 is significantly more accurate than the commonly used water models of same class (TIP3P and SPCE) in reproducing a comprehensive set of liquid bulk properties, over a wide range of temperatures. Beyond bulk properties, we show that OPC3 predicts the intrinsic charge hydration asymmetry (CHA) of water — a characteristic dependence of hydration free energy on the sign of the solute charge — in very close agreement with experiment. Two other recent 3-point rigid water models, TIP3PFB and H2ODC, each developed by its own, completely different optimization method, approach the global accuracy optimum represented by OPC3 in both the parameter space and accuracy of bulk properties. Thus, we argue that an accuracy limit of practical 3-point rigid non-polarizable models has effectively been reached; remaining accuracy issues are discussed.

  14. Accuracy limit of rigid 3-point water models.

    PubMed

    Izadi, Saeed; Onufriev, Alexey V

    2016-08-21

    Classical 3-point rigid water models are most widely used due to their computational efficiency. Recently, we introduced a new approach to constructing classical rigid water models [S. Izadi et al., J. Phys. Chem. Lett. 5, 3863 (2014)], which permits a virtually exhaustive search for globally optimal model parameters in the sub-space that is most relevant to the electrostatic properties of the water molecule in liquid phase. Here we apply the approach to develop a 3-point Optimal Point Charge (OPC3) water model. OPC3 is significantly more accurate than the commonly used water models of same class (TIP3P and SPCE) in reproducing a comprehensive set of liquid bulk properties, over a wide range of temperatures. Beyond bulk properties, we show that OPC3 predicts the intrinsic charge hydration asymmetry (CHA) of water - a characteristic dependence of hydration free energy on the sign of the solute charge - in very close agreement with experiment. Two other recent 3-point rigid water models, TIP3PFB and H2ODC, each developed by its own, completely different optimization method, approach the global accuracy optimum represented by OPC3 in both the parameter space and accuracy of bulk properties. Thus, we argue that an accuracy limit of practical 3-point rigid non-polarizable models has effectively been reached; remaining accuracy issues are discussed.

  15. Accuracy limit of rigid 3-point water models

    PubMed Central

    Izadi, Saeed

    2016-01-01

    Classical 3-point rigid water models are most widely used due to their computational efficiency. Recently, we introduced a new approach to constructing classical rigid water models [S. Izadi et al., J. Phys. Chem. Lett. 5, 3863 (2014)], which permits a virtually exhaustive search for globally optimal model parameters in the sub-space that is most relevant to the electrostatic properties of the water molecule in liquid phase. Here we apply the approach to develop a 3-point Optimal Point Charge (OPC3) water model. OPC3 is significantly more accurate than the commonly used water models of same class (TIP3P and SPCE) in reproducing a comprehensive set of liquid bulk properties, over a wide range of temperatures. Beyond bulk properties, we show that OPC3 predicts the intrinsic charge hydration asymmetry (CHA) of water — a characteristic dependence of hydration free energy on the sign of the solute charge — in very close agreement with experiment. Two other recent 3-point rigid water models, TIP3PFB and H2ODC, each developed by its own, completely different optimization method, approach the global accuracy optimum represented by OPC3 in both the parameter space and accuracy of bulk properties. Thus, we argue that an accuracy limit of practical 3-point rigid non-polarizable models has effectively been reached; remaining accuracy issues are discussed. PMID:27544113

  16. Amyloid Fibrillation of Insulin under Water-Limited Conditions

    PubMed Central

    Choi, Tae Su; Lee, Jong Wha; Jin, Kyeong Sik; Kim, Hugh I.

    2014-01-01

    Amyloid fibrillation in water-organic mixtures has been widely studied to understand the effect of protein-solvent interactions on the fibrillation process. In this study, we monitored insulin fibrillation in formamide and its methyl derivatives (formamide, N-methyl formamide, N,N-dimethyl formamide) in the presence and absence of water. These model solvent systems mimic the cellular environment by providing denaturing conditions and a hydrophobic environment with limited water content. Thioflavin T (ThT) assay revealed that binary mixtures of water with formamide and its methyl derivatives enhanced fibrillation rates and β-sheet abundance, whereas organic solvents suppressed insulin fibrillation. We utilized solution small-angle x-ray scattering (SAXS) and differential scanning calorimetry (DSC) to investigate the correlation between protein-solvent interactions and insulin fibrillation. SAXS experiments combined with simulated annealing of the protein indicated that the degree of denaturation of the hydrophobic core region at residues B11–B17 determines the fibrillation rate. In addition, DSC experiments suggested a crucial role of hydrophobic interactions in the fibrillation process. These results imply that an environment with limited water, which imitates a lipid membrane system, accelerates protein denaturation and the formation of intermolecular hydrophobic interactions during amyloid fibrillation. PMID:25418175

  17. Prediction of annual water consumption in Guangdong Province based on Bayesian neural network

    NASA Astrophysics Data System (ADS)

    Tian, Tao; Xue, Huifeng

    2017-06-01

    In the context of the implementation of the most stringent water resources management system, the role of water demand forecasting for regional water resources management is becoming increasingly significant. Based on the analysis of the influencing factors of water consumption in Guangdong Province, we made the forecast index system of annual water consumption, and constructed the forecast model of annual water consumption of BP neural network, then optimized the regularization BP neural network in utilization rate of water. The results showed that the average absolute percentage error of Bayesian neural network prediction model and BP neural network prediction model is 0.70% and 0.46% respectively. BP neural network model by Bayesian regularization is more ability to improve the accuracy of about 0.24%, more in line with the regional annual water demand forecast high precision requirements. Take the planning index value of Guangdong Province’s thirteen five plan into Bayesian neural network forecasting model, and its forecast value is 45.432 billion cubic meters, which will reach 456.04 billion cubic meters of red water in Guangdong Province in 2020.

  18. A view of annual water quality cycle and inter-annual variations in agricultural headwater catchment (Kervidy-Naizin, France)

    NASA Astrophysics Data System (ADS)

    Aubert, A.; Gascuel-odoux, C.; Merot, P.; Grimaldi, C.; Gruau, G.; Ruiz, L.

    2011-12-01

    Climatic conditions impact biotransformation and transfer of solutes. Therefore, they modify solute emissions in streams. Studying these modifications requires long term and detailed monitoring of both internal processes and river loads, which are rarely combined. The Kervidy-Naizin catchment, implemented in 1993, is part of the French network of catchment for environmental research (SOERE RBV, focused on the Critical Zone). It is an intensive agricultural catchment located in a temperate climate in Western France (Brittany) (Molenat et al., 2008; Morel et al., 2009). It presents shallow aquifers due to impervious bedrock. Both hydrology and water chemistry are monitored with a daily time step since 2000-01, as well as possible explanatory data (land use, meteorology, etc.). Concentrations in major anions in this catchment are extremely high, which make people call it a "saturated" catchment. We identified annual patterns for chloride, sulphate, dissolved organic and inorganic carbon and nitrate concentration variations. First, we considered the complete set of concentration data as function of the time. From that, we foresaw 3 cyclic temporal patterns. Then, from representing the concentrations as function of meteorological parameters, intra-annual hysteretic variations and their inter-annual variations were clearly identified. Our driving question is to know if and how climatic conditions are responsible for variations of the patterns in and between years. In winter, i.e. rainy and cold period, rainfall is closely linked to discharge because of a direct recharge to the shallow groundwater. Reversely, in transition periods (spring and fall) and hot periods, both rainfall and temperature influences discharge in relation to their range of variations. Moreover, biological processes, driven by temperature and wetness, also act during these periods. On the whole, we can emphasize the specificity of water chemistry patterns for each element. Noticeable differences

  19. Spacebased Observations of Oceanic Influence on the Annual Variation of South American Water Balance

    NASA Technical Reports Server (NTRS)

    Liu, W. Timothy; Xie, Xiaosu; Tang, Wenqing; Zlotnicki, Victor

    2006-01-01

    The mass change of South America (SA) continent measured by the Gravity Recovery and Climate Experiment (GRACE) imposes a constraint on the uncertainties in estimating the annual variation of rainfall measured by Tropical Rain Measuring Mission (TRMM) and ocean moisture influx derived from QuikSCAT data. The approximate balance of the mass change rate with the moisture influx less climatological river discharge, in agreement with the conservation principle, bolsters not only the credibility of the spacebased measurements, but supports the characterization of ocean's influence on the annual variation of continental water balance. The annual variation of rainfall is found to be in phase with the mass change rate in the Amazon and the La Plata basins, and the moisture advection across relevant segments of the Pacific and Atlantic coasts agrees with the annual cycle of rainfall in the two basins and the Andes mountains.

  20. Spacebased Observations of Oceanic Influence on the Annual Variation of South American Water Balance

    NASA Technical Reports Server (NTRS)

    Liu, W. Timothy; Xie, Xiaosu; Tang, Wenqing; Zlotnicki, Victor

    2006-01-01

    The mass change of South America (SA) continent measured by the Gravity Recovery and Climate Experiment (GRACE) imposes a constraint on the uncertainties in estimating the annual variation of rainfall measured by Tropical Rain Measuring Mission (TRMM) and ocean moisture influx derived from QuikSCAT data. The approximate balance of the mass change rate with the moisture influx less climatological river discharge, in agreement with the conservation principle, bolsters not only the credibility of the spacebased measurements, but supports the characterization of ocean's influence on the annual variation of continental water balance. The annual variation of rainfall is found to be in phase with the mass change rate in the Amazon and the La Plata basins, and the moisture advection across relevant segments of the Pacific and Atlantic coasts agrees with the annual cycle of rainfall in the two basins and the Andes mountains.

  1. Interactions between plant nutrients, water and carbon dioxide as factors limiting crop yields

    PubMed Central

    Gregory, P. J.; Simmonds, L. P.; Warren, G. P.

    1997-01-01

    Biomass production of annual crops is often directly proportional to the amounts of radiation intercepted, water transpired and nutrients taken up. In many places the amount of rainfall during the period of rapid crop growth is less than the potential rate of evaporation, so that depletion of stored soil water is commonplace. The rate of mineralization of nitrogen (N) from organic matter and the processes of nutrient loss are closely related to the availability of soil water. Results from Kenya indicate the rapid changes in nitrate availability following rain.
    Nutrient supply has a large effect on the quantity of radiation intercepted and hence, biomass production. There is considerable scope for encouraging canopy expansion to conserve water by reducing evaporation from the soil surface in environments where it is frequently rewetted, and where the unsaturated hydraulic conductivity of the soil is sufficient to supply water at the energy limited rate (e.g. northern Syria). In regions with high evaporative demand and coarse-textured soils (e.g. Niger), transpiration may be increased by management techniques that reduce drainage.
    Increases in atmospheric [CO2] are likely to have only a small impact on crop yields when allowance is made for the interacting effects of temperature, and water and nutrient supply.

  2. Annual extreme water levels from tide gauges: Contributing factors and geographic patterns

    NASA Astrophysics Data System (ADS)

    Merrifield, M. A.; Genz, A.; Kontoes, C.; Marra, J.

    2012-12-01

    Hourly time series from a global set of tide gauges are used to construct annual maximum water levels at each station. The high water levels are broken down into a predicted tidal component and a non-tidal residual, that is further separated into: (1) a seasonal component, (2) a low-frequency residual that accounts for non-seasonal sea level variability at time scales greater than a month, and (3) a high-frequency residual that captures short-term changes due to storms and other oceanographic processes. The mean annual extreme water level is well described by the total water level variance (tide plus non-tidal residual) at each station. Water level variance on a continuous, global scale is defined using a global tide model, sea surface height from satellite altimetry, and atmospheric forcing fields. The variance fields are combined to produce a global map of extreme water levels that compares well with tide gauge extremes at each station location. The relative importance of the tides and the non-tidal residual components to annual extreme water levels is specified.

  3. 12 CFR 1026.55 - Limitations on increasing annual percentage rates, fees, and charges.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... PROTECTION TRUTH IN LENDING (REGULATION Z) Special Rules Applicable to Credit Card Accounts and Open-End...)(2)(iii), or (b)(2)(xii) on a credit card account under an open-end (not home-secured) consumer credit plan. (b) Exceptions. A card issuer may increase an annual percentage rate or a fee or charge...

  4. 12 CFR 1026.55 - Limitations on increasing annual percentage rates, fees, and charges.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... PROTECTION TRUTH IN LENDING (REGULATION Z) Special Rules Applicable to Credit Card Accounts and Open-End...)(2)(iii), or (b)(2)(xii) on a credit card account under an open-end (not home-secured) consumer credit plan. (b) Exceptions. A card issuer may increase an annual percentage rate or a fee or charge...

  5. 12 CFR 1026.55 - Limitations on increasing annual percentage rates, fees, and charges.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... PROTECTION TRUTH IN LENDING (REGULATION Z) Special Rules Applicable to Credit Card Accounts and Open-End...)(2)(iii), or (b)(2)(xii) on a credit card account under an open-end (not home-secured) consumer credit plan. (b) Exceptions. A card issuer may increase an annual percentage rate or a fee or charge...

  6. 50 CFR 648.70 - Surfclam and ocean quahog Annual Catch Limit (ACL).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Surfclam and ocean quahog Annual Catch... Management Measures for the Atlantic Surf Clam and Ocean Quahog Fisheries § 648.70 Surfclam and ocean quahog... ocean quahog fisheries, which shall be equal to the ABCs recommended by the SSC. (1) Sectors. The...

  7. 50 CFR 648.70 - Surfclam and ocean quahog Annual Catch Limit (ACL).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Surfclam and ocean quahog Annual Catch... Management Measures for the Atlantic Surf Clam and Ocean Quahog Fisheries § 648.70 Surfclam and ocean quahog... ocean quahog fisheries, which shall be equal to the ABCs recommended by the SSC. (1) Sectors. The...

  8. 50 CFR 648.100 - Summer flounder Annual Catch Limit (ACL).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) The Summer Flounder Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial... recommended by the SSC. (1) Sector allocations. The commercial and recreational fishing sector ACLs will be... sector ACLs may be established on an annual basis for up to 3 years at a time, dependent on whether...

  9. 50 CFR 648.100 - Summer flounder Annual Catch Limit (ACL).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) The Summer Flounder Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial... recommended by the SSC. (1) Sector allocations. The commercial and recreational fishing sector ACLs will be... sector ACLs may be established on an annual basis for up to 3 years at a time, dependent on whether...

  10. 50 CFR 648.100 - Summer flounder Annual Catch Limit (ACL).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) The Summer Flounder Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial... recommended by the SSC. (1) Sector allocations. The commercial and recreational fishing sector ACLs will be... sector ACLs may be established on an annual basis for up to 3 years at a time, dependent on whether...

  11. 29 CFR 2590.715-2711 - No lifetime or annual limits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (c) of this section). (2) Condition-based exclusions. The rules of this section do not prevent a..., DEPARTMENT OF LABOR GROUP HEALTH PLANS RULES AND REGULATIONS FOR GROUP HEALTH PLANS Other Requirements § 2590.... (2) Annual limits—(i) General rule. Except as provided in paragraphs (a)(2)(ii), (b), and (d) of...

  12. 29 CFR 2590.715-2711 - No lifetime or annual limits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (c) of this section). (2) Condition-based exclusions. The rules of this section do not prevent a..., DEPARTMENT OF LABOR GROUP HEALTH PLANS RULES AND REGULATIONS FOR GROUP HEALTH PLANS Other Requirements § 2590.... (2) Annual limits—(i) General rule. Except as provided in paragraphs (a)(2)(ii), (b), and (d) of...

  13. Water Activity Limits the Hygroscopic Growth Factor of Organic Aerosols

    NASA Astrophysics Data System (ADS)

    Rodriguez, L. I.; Cabrera, J. A.; Golden, D.; Tabazadeh, A.

    2007-12-01

    In this work we study the hygroscopic behavior of organic aerosols, which has important implications for Earth's climate. The hygroscopic growth factor (HGF) is defined as the ratio of the diameter of a spherical particle when it is exposed to dry conditions to that at humid conditions. We present a new formulation to express the HGF of an aerosol particle as a function of water activity (aw) in the aqueous phase. This new formulation matches reported HGFs for common inorganic salts and water-miscible organic particles that are known to deliquesce into aqueous drops at high relative humidities (RH). Many studies use tandem differential mobility analyzers (TDMA) to determine the HGF of organic aerosols. For example, Brooks et al. used a TDMA to measure a HGF of 1.2 for 2 μm phthalic acid (PA) particles at 90% RH (aw= 0.9). However, water activity limits the growth of a particle that can be attributed to water uptake. We have assembled a vapor pressure apparatus to measure aw of aqueous solutions at room temperature. Measured water activities for PA, used in our growth formulation, yield a HGF of ~ 1.0005 for 2 μm PA particles at 90% RH. Comparing our results against Brooks et al. suggests that TDMA experiments may grossly overestimate the HGF of PA particles since water activity limits this growth to below 1.0005. Alternatively, we suggest that the adsorption of a negligible mass of water by a highly porous PA particle can lead to an apparent growth in particle size by changing its morphology. Other studies also use TDMAs to measure HGFs of secondary organic aerosols (SOAs). HGFs reported for SOAs are very similar to PA, suggesting that the observed growth may be due to morphological changes in particle size rather than water uptake as commonly assumed. We built a smog chamber where an organic precursor, such as d-limonene, reacts with nitrogen oxides under UV radiation to produce SOAs. We compare the HGFs for SOAs obtained with our method to those obtained with

  14. Long term mean annual water temperature for stream reaches in Pacific Northwest United States

    USGS Publications Warehouse

    ,

    2012-01-01

    Long-term mean annual water temperature (degrees Celsius) was estimated for the E2RF1 stream network (Brakebill and Terziotti, 2011) located within the Pacific Northwest region of the United States (HUC2 = 17; the Columbia River basin, the Puget Sound watershed, the coastal drainages of Washington and Oregon, and the closed basins in southern Oregon). Multiple linear regressions were used to select reach-scale watershed attributes (explanatory variables) for predicting the long-term mean annual water temperature (dependent variable) at a set of USGS water-quality monitoring stations. The results from the multiple linear regressions were used to predict the long-term mean water temperature for the Pacific Northwest reaches in the E2RF1 network.

  15. Annual ground-water use in the Twin Cities metropolitan area, Minnesota, 1970-79

    USGS Publications Warehouse

    Horn, M.A.

    1984-01-01

    Annual ground-water use in the Twin Cities Metropolitan Area from 1970-79 is presented by aquifer and type of use. The data show that most ground water is withdrawn from wells in the Prairie du Chien-Jordan aquifer and that major uses of the water are for self-supplied industry and public supplies. Annual ground-water-use data are presented by county for each of the five major aquifers; Prairie du Chien-Jordan, Mount Simon-Hinckley, Ironton-Galesville, St. Peter, and drift. The data also are presented by county for each major use type, including public supply, self-supplied industry, commercial air-conditioning, irrigation, lake-level maintenance, and dewatering. The data were collected initially by the Minnesota Department of Natural Resources and were supplemented by data collected by the U.S. Geological Survey.

  16. The 13th Annual James L. Waters Symposium at Pittcon: Electron Spectroscopy for Chemical Analysis

    ERIC Educational Resources Information Center

    Baltrus, John P.

    2004-01-01

    The objective of the James L. Waters Annual Symposium is to recognize pioneers in the development of instrumentation by preserving the early history of the cooperation and important contributions of inventors, scientists, engineers, entrepreneurs, and marketing organizations. The symposium was held in Pittsburgh, United States in March 2002 to…

  17. The 14th Annual James L. Waters Symposium at Pittcon: Raman Spectroscopy

    ERIC Educational Resources Information Center

    Gardner, Charles W.

    2007-01-01

    Raman Spectroscopy was the main topic of the 14th Annual James L. Waters Symposium, which was held in March 2003 at Pittcon. The development of the enabling technologies that have made Raman spectroscopy a routine analysis tool in many laboratories worldwide is discussed.

  18. Historic role of fire in determining annual water yield from Tenderfoot Creek Experimental Forest, Montana, USA

    Treesearch

    Ward W. McCaughey; Phillip E. Farnes; Katherine J. Hansen

    1997-01-01

    Water production from mountain watersheds depends on total precipitation input, the type and distribution of precipitation, the amount intercepted in tree canopies, and losses to evaporation, transpiration and groundwater. A systematic process was developed to estimate historic average annual runoff based on fire patterns, habitat cover types and precipitation patterns...

  19. The 13th Annual James L. Waters Symposium at Pittcon: Electron Spectroscopy for Chemical Analysis

    NASA Astrophysics Data System (ADS)

    Baltrus, John P.

    2004-12-01

    The 13th Annual James L. Waters Symposium focused on a review of the origin, development, implementation, and commercialization of electron spectroscopy for chemical analysis by four of the pioneers in the field. The subsequent articles summarize the presentations made in that symposium.

  20. The 14th Annual James L. Waters Symposium at Pittcon: Raman Spectroscopy

    ERIC Educational Resources Information Center

    Gardner, Charles W.

    2007-01-01

    Raman Spectroscopy was the main topic of the 14th Annual James L. Waters Symposium, which was held in March 2003 at Pittcon. The development of the enabling technologies that have made Raman spectroscopy a routine analysis tool in many laboratories worldwide is discussed.

  1. The annual cycle of water vapor on Mars as observed by the Thermal Emission Spectrometer

    NASA Astrophysics Data System (ADS)

    Smith, M. D.

    2001-12-01

    We report here on the latitude, longitude, and seasonal dependence of water vapor abundance for over one full Martian year as observed by the Mars Global Surveyor Thermal Emission Spectrometer (TES). A maximum in water vapor abundance is observed at high latitudes during mid-summer in both hemispheres, reaching a maximum value of ~100 pr-μ m in the north and ~50 pr-μ m in the south. Low water vapor abundance (<5 pr-μ m) is observed at middle and high latitudes in the fall and winter of both hemispheres. There are large differences in the hemispheric (north versus south) and seasonal (perihelion versus aphelion) behavior of water vapor. The latitudinal and seasonal dependence of the decay of the northern summer water vapor maximum implies cross-equatorial transport of water to the southern hemisphere, while there is little or no corresponding transport during the decay of the southern hemisphere summer maximum. A very steep latitudinal gradient in water vapor abundance (high in the north) forms during early northern summer (Ls= 90o--150o), while water vapor is distributed more uniformly in latitude during early southern summer (Ls= 270o--330o). The annually-averaged amount of water vapor in the Martian atmosphere is 17 pr-μ m in the northern hemisphere and 9.5 pr-μ m in the southern hemisphere. However, when referenced to a 6.1 mbar pressure surface to remove the effect of topography, the annually-averaged amount of water vapor becomes 17 pr-μ m in the latitude band from 10oS--40oN, and 12 pr-μ m everywhere else. The latitude-longitude dependence of annually-averaged water vapor (corrected for topography) has a significant positive correlation with albedo and significant negative correlations with thermal inertia and surface pressure.

  2. Water Quality Trends in the Entiat River Subbasin: Final 2008 Annual Report.

    SciTech Connect

    Woodsmith, Richard; Bookter, Andy

    2009-03-30

    The ISEMP program monitors the status and trend of water quality elements that may affect restoration project effectiveness in the Entiat subbasin. As part of this effort, the PNW Research Station (PNW) measures, analyzes and interprets temporal trends in natural stream water pH, dissolved oxygen, specific conductivity and temperature. The Entiat River is currently on the Clean Water Act 303(d) list for pH exceedence, and there is insufficient information to determine the spatial and temporal extent or potential causes of this exceedence. In the spring 2008, PNW redeployed data-logging, multiparameter probes at four locations in the Entiat subbasin to measure water quality parameters, focusing on pH. This resumed previous data collection that was interrupted by river ice in early December 2007. Instruments were again removed from the river in early December 2008. This annual report covers the period from December 2007 through December 2008. The highest pH values occurred during the low-flow period from midsummer through the following midspring then dropped sharply during the annual snowmelt runoff period from late spring through early summer. Water temperature began rapidly increasing during the receding limb of the annual snowmelt hydrograph. Highest mean monthly temperatures occurred in July and August, while instantaneous maxima occurred during the period July-September. Dissolved oxygen reached its lowest levels during the period of highest water temperature in July-September. Specific conductivity remained very low at all sites throughout the year.

  3. Role of detection limits in drinking water regulation.

    PubMed

    Calder, Ryan S D; Schmitt, Ketra A

    2010-11-01

    Some commentators on environmental science and policy have claimed that advances in analytical chemistry, reflected by an ability to detect contaminants at ever-decreasing concentrations, lead to regulations stricter than justified by available toxicological data. We evaluate this claim in the context of drinking water regulation, with respect to contaminants regulated under the Safe Drinking Water Act (SDWA). We examine the relationships between historical and present maximum contaminant levels and goals in the greater context of detection capability and evaluate the extent to which different aspects of the regulatory apparatus (i.e., analytical capability, cost-benefit analysis, analysis of competing risks, and available toxicological data) influence the regulatory process. Our findings do not support the claim that decreases in detection limit lead to more stringent regulation in the context of drinking water regulation in the United States. Further, based on our analysis of the National Primary Drinking Water Regulation and existing United States Environmental Protection Agency approaches to establishing the practical quantifiable level, we conclude that in the absence of changes to the underlying toxicological model, regulatory revision is unlikely.

  4. Forests in a water limited world under climate change

    NASA Astrophysics Data System (ADS)

    Mátyás, Csaba; Sun, Ge

    2014-08-01

    The debate on ecological and climatic benefits of planted forests at the sensitive dry edge of the closed forest belt (i.e. at the ‘xeric limits’) is still unresolved. Forests sequester atmospheric carbon dioxide, accumulate biomass, control water erosion and dust storms, reduce river sedimentation, and mitigate small floods. However, planting trees in areas previously dominated by grassland or cropland can dramatically alter the energy and water balances at multiple scales. The forest/grassland transition zone is especially vulnerable to projected drastic temperature and precipitation shifts and growing extremes due to its high ecohydrological sensitivity. We investigated some of the relevant aspects of the ecological and climatic role of forests and potential impacts of climate change at the dryland margins of the temperate-continental zone using case studies from China, the United States and SE Europe (Hungary). We found that, contrary to popular expectations, the effects of forest cover on regional climate might be limited and the influence of forestation on water resources might be negative. Planted forests generally reduce stream flow and lower groundwater table level because of higher water use than previous land cover types. Increased evaporation potential due to global warming and/or extreme drought events is likely to reduce areas that are appropriate for tree growth and forest establishment. Ecologically conscious forest management and forestation planning should be adjusted to the local, projected hydrologic and climatic conditions, and should also consider non-forest alternative land uses.

  5. Shallow water equations: viscous solutions and inviscid limit

    NASA Astrophysics Data System (ADS)

    Chen, Gui-Qiang; Perepelitsa, Mikhail

    2012-12-01

    We establish the inviscid limit of the viscous shallow water equations to the Saint-Venant system. For the viscous equations, the viscosity terms are more degenerate when the shallow water is close to the bottom, in comparison with the classical Navier-Stokes equations for barotropic gases; thus, the analysis in our earlier work for the classical Navier-Stokes equations does not apply directly, which require new estimates to deal with the additional degeneracy. We first introduce a notion of entropy solutions to the viscous shallow water equations and develop an approach to establish the global existence of such solutions and their uniform energy-type estimates with respect to the viscosity coefficient. These uniform estimates yield the existence of measure-valued solutions to the Saint-Venant system generated by the viscous solutions. Based on the uniform energy-type estimates and the features of the Saint-Venant system, we further establish that the entropy dissipation measures of the viscous solutions for weak entropy-entropy flux pairs, generated by compactly supported C 2 test-functions, are confined in a compact set in H -1, which yields that the measure-valued solutions are confined by the Tartar-Murat commutator relation. Then, the reduction theorem established in Chen and Perepelitsa [5] for the measure-valued solutions with unbounded support leads to the convergence of the viscous solutions to a finite-energy entropy solution of the Saint-Venant system with finite-energy initial data, which is relative with respect to the different end-states of the bottom topography of the shallow water at infinity. The analysis also applies to the inviscid limit problem for the Saint-Venant system in the presence of friction.

  6. Detection limits of organic contaminants in drinking water

    SciTech Connect

    Draper, W.M.; Dhoot, J.S.; Dhaliwal, J.S.; Remoy, J.W.; Perera, S.K.; Baumann, F.J.

    1998-06-01

    This article examines some of the experimental variables that can contribute to the observed variability in laboratory performance. The examples provided suggest that method detection limits (MDLs) would be more uniform among laboratories if (1) uniform spike concentrations were used in MDL determination; (2) analytical methods were more uniform as to procedures, reagents, and materials; and (3) tighter guidelines were established for conducting MDL experiments and handling MDL data. The pooling of data from multiple spike levels (or any other means to increase sample size) minimizes random error in MDL determination. Improved control in MDL determination would lead to better information on laboratory capabilities, and this in turn would improve the technical basis for reporting limits, trigger levels, and water quality standards.

  7. Seaward Limit of Significant Sand Transport by Waves: An Annual Zonation for Seasonal Profiles.

    DTIC Science & Technology

    1981-01-01

    for significant profile changes (elevation excursions greater than ±0.5 foot or ±0.15 meter) throughout a yearly cycle of wave climate . Linear wave...NOTES 19. KEY WOR S (Continue on reverse side If neceeary end Identify by block number) Beach rofiles Coastal engineering Sand transport Wave climate ...and seaward bounds of the shoal zone, are calculated in Section II, using sand characteristics and statistics of annual wave climate for a given

  8. The Annual Cycle of Water Vapor on Mars as Observed by the Thermal Emission Spectrometer

    NASA Technical Reports Server (NTRS)

    Smith, Michael D.; Vondrak, Richard R. (Technical Monitor)

    2001-01-01

    Spectra taken by the Mars Global Surveyor Thermal Emission Spectrometer (TES) have been used to monitor the latitude, longitude, and seasonal dependence of water vapor for over one full Martian year (March 1999-March 2001). A maximum in water vapor abundance is observed at high latitudes during mid-summer in both hemispheres, reaching a maximum value of approximately 100 pr-micrometer in the north and approximately 50 pr-micrometer in the south. Low water vapor abundance (<5 pr-micrometer) is observed at middle and high latitudes in the fall and winter of both hemispheres. There are large differences in the hemispheric (north versus south) and seasonal (perihelion versus aphelion) behavior of water vapor. The latitudinal and seasonal dependence of the decay of the northern summer water vapor maximum implies cross-equatorial transport of water to the southern hemisphere, while there is little or no corresponding transport during the decay of the southern hemisphere summer maximum. The latitude-longitude dependence of annually-averaged water vapor (corrected for topography) has a significant positive correlation with albedo and significant negative correlations with thermal inertia and surface pressure. Comparison of TES results with those retrieved from the Viking Orbiter Mars Atmospheric Water Detectors (MAWD) experiments shows some similar features, but also many significant differences. The southern hemisphere maximum observed by TES was not observed by MAWD and the large latitudinal gradient in annually-averaged water vapor observed by MAWD does not appear in the TES results.

  9. Does the rhizosphere hydrophobicity limit root water uptake?

    NASA Astrophysics Data System (ADS)

    Zare, Mohsen; Ahmed, Mutez; Kroener, Eva; Carminati, Andrea

    2015-04-01

    The ability of plants to extract water from the soil is influenced by the hydraulic conductivity of roots and their rhizosphere. Recent experiments showed that the rhizosphere turned hydrophobic after drying and it remained dry after rewetting [1]. Our objective was to investigate whether rhizosphere hydrophobicity is a limit to root water uptake after drying. To quantify the effect of rhizosphere hydrophobicity on root water uptake, we used neutron radiography to trace the transport of deuterated water (D2O) in the roots of lupines experiencing a severe, local soil drying. The plants were grown in aluminum containers (30×30×1 cm) filled with sandy soil. The soil was partitioned into nine compartments using three horizontal and three vertical layers of coarse sand (thickness of 1cm) as capillary barrier. When the plants were 28 days old, we let one of the upper lateral compartments dry to a water content of 2-4%, while keeping the other compartments to a water content of 20%. Then we injected 10 ml of D2O in the dry compartment and 10 ml in the symmetric location. The radiographs showed that root water uptake in the soil region that was let dry and then irrigated was 4-8 times smaller than in the wet soil region[2]. In a parallel experiment, we used neutron radiography to monitor the rehydration of lupine roots that were irrigated after a severe drying experiment. Based on root swelling and additional data on the xylem pressure, we calculated the hydraulic conductivity of the root-rhizosphere continuum. We found that the hydraulic conductivity of the root-rhizosphere continuum was initially 5.75×10-14 m s-1and it increased to 4.26×10-12 m s-1after four hours. Both experiments show that rhizosphere hydrophobicity after drying is associated with a reduction in root water uptake and a big decrease in hydraulic conductivity of the soil-root system. [1] Carminati et al (2010) Plant and Soil. Vol. 332: 163-176. [2] Zarebanadkouki and Carmianti (2013) Journal of Plant

  10. Nutrient and water addition effects on day- and night-time conductance and transpiration in a C3 desert annual.

    PubMed

    Ludwig, Fulco; Jewitt, Rebecca A; Donovan, Lisa A

    2006-06-01

    Recent research has shown that many C3 plant species have significant stomatal opening and transpire water at night even in desert habitats. Day-time stomatal regulation is expected to maximize carbon gain and prevent runaway cavitation, but little is known about the effect of soil resource availability on night-time stomatal conductance (g) and transpiration (E). Water (low and high) and nutrients (low and high) were applied factorially during the growing season to naturally occurring seedlings of the annual Helianthus anomalus. Plant height and biomass were greatest in the treatment where both water and nutrients were added, confirming resource limitations in this habitat. Plants from all treatments showed significant night-time g (approximately 0.07 mol m(-2) s(-1)) and E (approximately 1.5 mol m(-2) s(-1)). In July, water and nutrient additions had few effects on day- or night-time gas exchange. In August, however, plants in the nutrient addition treatments had lower day-time photosynthesis, g and E, paralleled by lower night-time g and E. Lower predawn water potentials and higher integrated photosynthetic water-use efficiency suggests that the nutrient addition indirectly induced a mild water stress. Thus, soil resources can affect night-time g and E in a manner parallel to day-time, although additional factors may also be involved.

  11. A water use and growth model for Eucalyptus plantation in water-limited conditions

    SciTech Connect

    Calder, I.R.

    1992-12-31

    To investigate the environmental impact of plantation forestry using fast-growing tree species in southern India, a program of field studies was initiated in 1987 specifically to measure the water use, nutrient uptake and growth rates of the plantations. A water use and growth (WAG) model is proposed for calculating transpiration and growth of Eucalyptus plantation in water-limited conditions. The model is based on the measured relationships between transpiration rate and basal cross-sectional area and soil moisture availability. The volume growth rate (in water-limited conditions) is assumed to be proportional to the volume of water transpired. The model is calibrated using (deuterium tracing) measurements of transpiration and measurements of growth recorded at the Puradal experimental plantation, Karnataka, southern India.

  12. 29 CFR 2590.715-2711 - No lifetime or annual limits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... individuals who did not lose coverage by reason of reaching a lifetime limit on the dollar value of all... individuals who did not lose coverage by reason of reaching a lifetime limit on the dollar value of all... limit on the dollar value of all benefits for any individual (which, under this section, is no longer...

  13. Plasma generation in mass-limited water targets

    NASA Astrophysics Data System (ADS)

    Hah, Jungmoo; Liberty, Kirk; Nees, John; Krushelnick, Karl; Thomas, Alexander

    2014-10-01

    One major problem associated with high repetition-rate experiment is obtaining a suitable new target for each shot, while maintaining shot-to-shot spatial stability. For high repetition-rate laser experiments with solid targets, rotating stage is usually used for moving a target point, which causes stability and size problems. To solve these problems, some researchers have tried to replace solid targets with liquid stream or droplet. Here, we use a syringe pump, a piezoelectric device and a tungsten needle to make continuous and stable water droplets with a diameter of ~ 2 μm. These mass-limited water droplets as a target have some advantages. First, heat dissipation is blocked, so the target is entirely heated. Second, effective spatial contrast is improved by reducing the interaction between lower intensity spatial wings of the beam and a single-micron target. Third, at the relativistic laser intensities, a smaller target allows for higher electron densities at the target's back surface, which enhances field's strength for ion acceleration. For these advantages, it is required that we understand plasma generation processes. Therefore, we investigate the processes by irradiating fs laser pulses to mass-limited droplets and these interactions are captured by CCD.

  14. Pesticides water decontamination in oxygen-limited conditions.

    PubMed

    Suciu, Nicoleta Alina; Ferrari, Federico; Vasileiadis, Sotirios; Merli, Annalisa; Capri, Ettore; Trevisan, Marco

    2013-01-01

    This study was undertaken to develop a laboratory bioreactor, with a functioning principle similar with that of biobed systems but working in oxygen-limited conditions, suitable for decontaminating wastewater mixtures with pesticides. The system is composed by two cylindrical plastic containers. The first one, where the pesticides solution is collected, is open, whereas the second one, where the biomass is disposed, is closed. The pesticides solution was pumped at the biomass surface and subsequently recollected and disposed in the first container. Four pesticides with different physical-chemical characteristics were tested. The results obtained showed a relatively good capacity of the developed prototype to decontaminate waste water containing the mixture of pesticides. The time of the experiment, the number of cycles that the solution made in the system and the environmental temperature have a significantly influence for the decontamination of acetochlor and chlorpyrifos whereas for the decontamination of terbuthylazine and metalaxyl no significant influence was observed. Even if the present prototype could represent a valid solution to manage the water pesticides residues in a farm and to increase the confidence of bystanders and residents, the practical difficulties when replacing the biomass could represent a limit of the system.

  15. Evolutionary speed limited by water in arid Australia

    PubMed Central

    Goldie, Xavier; Gillman, Len; Crisp, Mike; Wright, Shane

    2010-01-01

    The covariation of biodiversity with climate is a fundamental pattern in nature. However, despite the ubiquity of this relationship, a consensus on the ultimate cause remains elusive. The evolutionary speed hypothesis posits direct mechanistic links between ambient temperature, the tempo of micro-evolution and, ultimately, species richness. Previous research has demonstrated faster rates of molecular evolution in warmer climates for a broad range of poikilothermic and homeothermic organisms, in both terrestrial and aquatic environments. In terrestrial systems, species richness increases with both temperature and water availability and the interaction of those terms: productivity. However, the influence of water availability as an independent variable on micro-evolutionary processes has not been examined previously. Here, using methodology that limits the potentially confounding role of cladogenetic and demographic processes, we report, to our knowledge, the first evidence that woody plants living in the arid Australian Outback are evolving more slowly than related species growing at similar latitudes in moist habitats on the mesic continental margins. These results support a modified evolutionary speed explanation for the relationship between the water-energy balance and plant diversity patterns. PMID:20410038

  16. Upper limits to the water abundance in starburst galaxies

    NASA Astrophysics Data System (ADS)

    Wilson, C. D.; Booth, R. S.; Olofsson, A. O. H.; Olberg, M.; Persson, C. M.; Sandqvist, Aa.; Hjalmarson, Â.; Buat, V.; Encrenaz, P. J.; Fich, M.; Frisk, U.; Gerin, M.; Rydback, G.; Wiklind, T.

    2007-07-01

    Aims:We have searched for emission from the 557 GHz ortho-water line in the interstellar medium of six nearby starburst galaxies. Methods: We used the Odin satellite to observe the 110{-}101 transition of o-H2O in the galaxies NGC 253, IC 342, M 82, NGC 4258, CenA, and M 51. None of the galaxies in our sample was detected. Results: We derive three sigma upper limits to the H2O abundance relative to H2 ranging from 2×10-9 to 1×10-8. The best of these upper limits are comparable to the measured abundance of H2O in the Galactic star forming region W3. However, if only 10% of the molecular gas is in very dense cores, then the water abundance limits in the cores themselves would be larger by a factor of 10 i.e. 2×10-8 to 1×10-7. Conclusions: These observations suggest that detections of H2O emission in galaxies with the upcoming Herschel Space Observatory are likely to require on-source integration times of an hour or more except in the very brightest extragalactic targets such as M 82 and NGC 253. Based on observations with Odin, a Swedish-led satellite project funded jointly by the Swedish National Space Board (SNSB), the Canadian Space Agency (CSA), the National Technology Agency of Finland (Tekes) and Centre National d'Etude Spatiale (CNES). The Swedish Space Corporation has been the industrial prime contractor and also is operating the satellite.

  17. Temporal and spatial variability of annual extreme water level in the Pearl River Delta region, China

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Yan, Yixin; Zheng, Jinhai; Li, Ling; Dong, Xue; Cai, Huijuan

    2009-10-01

    This paper is concerned with identifying the spatial and temporal patterns in the annual maximum and minimum water level in the Pearl River Delta (PRD) region. The Mann-Kendall test and Pettitt test are used to detect trends and abrupt change points, and the Trend Free Pre-Whitening (TFPW) approach then eliminates the effect of serial correlation in data series with significant autocorrelation. Approximately fifty years of the annual hydrological variables from 18 stations in the three major rivers (the West River, the North River, and the East River) are examined. The changing trends of the extremes in water level show different features in different parts of the PRD region. Generally speaking, in the upper part of the delta, the water levels show a decreasing trend while in the middle and lower part there is an increasing trend. This spatial pattern of the extreme water level variation is unlikely to be due to a long-term change in stream flow in the PRD region because the water level changes do not always coincide with the extreme stream flow variations. Sand excavation initiated in the 1980s and continuing for more than 20 years in almost all tributaries around the PRD region is one of the most serious intensive human activities affecting water levels. The result of the Pettitt test indicates that most abrupt change points occurred in 1980s-1990s, which reveals that sand excavation and channel regulation are likely to have been the most significant factors contributing to the change over this period. These anthropogenic activities modify the annual extreme water level dramatically in a way that affects the morphology of river channels and estuaries of the PRD and also the redistribution of discharge. However, there are differences in the geographic locations of significant trends for the water level investigated, which implies that these impacts are not spatially uniform.

  18. Recent trends in vegetation greenness in China significantly altered annual evapotranspiration and water yield

    NASA Astrophysics Data System (ADS)

    Liu, Yibo; Xiao, Jingfeng; Ju, Weimin; Xu, Ke; Zhou, Yanlian; Zhao, Yuntai

    2016-09-01

    There has been growing evidence that vegetation greenness has been increasing in many parts of the northern middle and high latitudes including China during the last three to four decades. However, the effects of increasing vegetation greenness particularly afforestation on the hydrological cycle have been controversial. We used a process-based ecosystem model and a satellite-derived leaf area index (LAI) dataset to examine how the changes in vegetation greenness affected annual evapotranspiration (ET) and water yield for China over the period from 2000 to 2014. Significant trends in vegetation greenness were observed in 26.1% of China’s land area. We used two model simulations driven with original and detrended LAI, respectively, to assess the effects of vegetation ‘greening’ and ‘browning’ on terrestrial ET and water yield. On a per-pixel basis, vegetation greening increased annual ET and decreased water yield, while vegetation browning reduced ET and increased water yield. At the large river basin and national scales, the greening trends also had positive effects on annual ET and had negative effects on water yield. Our results showed that the effects of the changes in vegetation greenness on the hydrological cycle varied with spatial scale. Afforestation efforts perhaps should focus on southern China with larger water supply given the water crisis in northern China and the negative effects of vegetation greening on water yield. Future studies on the effects of the greenness changes on the hydrological cycle are needed to account for the feedbacks to the climate.

  19. Impact of Pilot Light Modeling on the Predicted Annual Performance of Residential Gas Water Heaters: Preprint

    SciTech Connect

    Maguire, J.; Burch, J.

    2013-08-01

    Modeling residential water heaters with dynamic simulation models can provide accurate estimates of their annual energy consumption, if the units? characteristics and use conditions are known. Most gas storage water heaters (GSWHs) include a standing pilot light. It is generally assumed that the pilot light energy will help make up standby losses and have no impact on the predicted annual energy consumption. However, that is not always the case. The gas input rate and conversion efficiency of a pilot light for a GSWH were determined from laboratory data. The data were used in simulations of a typical GSWH with and without a pilot light, for two cases: 1) the GSWH is used alone; and 2) the GSWH is the second tank in a solar water heating (SWH) system. The sensitivity of wasted pilot light energy to annual hot water use, climate, and installation location was examined. The GSWH used alone in unconditioned space in a hot climate had a slight increase in energy consumption. The GSWH with a pilot light used as a backup to an SWH used up to 80% more auxiliary energy than one without in hot, sunny locations, from increased tank losses.

  20. 40 CFR Appendix A to Part 72 - Methodology for Annualization of Emissions Limits

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Emissions Limits A Appendix A to Part 72 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Pt. 72, App. A Appendix A to Part 72—Methodology for... section 402(18) of the CAA. Many emission limits are enforced on a shorter term basis (or averaging...

  1. Diffusion Limited Supercritical Water Oxidation (SCWO) in Microgravity Environments

    NASA Technical Reports Server (NTRS)

    Hicks, M. C.; Lauver, R. W.; Hegde, U. G.; Sikora, T. J.

    2006-01-01

    Tests designed to quantify the gravitational effects on thermal mixing and reactant injection in a Supercritical Water Oxidation (SCWO) reactor have recently been performed in the Zero Gravity Facility (ZGF) at NASA s Glenn Research Center. An artificial waste stream, comprising aqueous mixtures of methanol, was pressurized to approximately 250 atm and then heated to 450 C. After uniform temperatures in the reactor were verified, a controlled injection of air was initiated through a specially designed injector to simulate diffusion limited reactions typical in most continuous flow reactors. Results from a thermal mapping of the reaction zone in both 1-g and 0-g environments are compared. Additionally, results of a numerical model of the test configuration are presented to illustrate first order effects on reactant mixing and thermal transport in the absence of gravity.

  2. Effects of precipitation variability on carbon and water fluxes in the understorey of a nitrogen-limited montado ecosystem.

    PubMed

    Jongen, Marjan; Unger, Stephan; Santos Pereira, João

    2014-12-01

    To date the implications of greater intra-annual variability and extremes in precipitation on ecosystem functioning have received little attention. This study presents results on soil and vegetation carbon and water fluxes in the understorey of a Mediterranean oak woodland in response to increasing precipitation variability, with an extension of the dry period between precipitation events from 3 to 6 weeks, without altering total annual precipitation inputs. With prolonged dry periods soil moisture did breach the stress thresholds for ecosystem processes, which led to short-term treatment differences in photosynthesis, but not in system carbon losses, with subsequent short-term decreases in net ecosystem exchange. Independent of treatment, irrigation events rapidly increased carbon and water fluxes. However, contradicting the predictions drawn from the 'bucket model', over the course of the growing season no all-over treatment differences were found in system assimilation and respiration, nor in evapotranspiration and ecosystem water use efficiency. This lack of responsiveness is attributed to the ecosystem's resilience to low soil moisture during the growing season of the herbaceous understorey, with temperature rather than soil moisture controlling key ecosystem processes. Moreover, severe nitrogen limitation of the studied ecosystem may explain the lack of moisture effects on net system carbon dynamics. Thus, although the bucket model predicts changes in soil water dynamics with increasing precipitation variability, ecosystem responses to more extreme precipitation regimes may be influenced by additional factors, such as inter-annual variability in nutrient availability.

  3. 50 CFR Table 33 to Part 679 - Annual Apportion of Amendment 80 Species ITAC Between the Amendment 80 and BSAI Trawl Limited...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Annual Apportion of Amendment 80 Species ITAC Between the Amendment 80 and BSAI Trawl Limited Access Sectors (Except Yellowfin Sole) 33 Table 33... ALASKA Pt. 679, Table 33 Table 33 to Part 679— Annual Apportion of Amendment 80 Species ITAC Between...

  4. Kinetic Limited Water Evaporation in Hydrophilic Nanofluidic Channels

    NASA Astrophysics Data System (ADS)

    Li, Yinxiao; Alibakhshi, Mohammad Amin; Xie, Quan; Duan, Chuanhua

    2015-11-01

    Capillary evaporation is one of the most efficient approaches for heat and mass transfer, but the interfacial resistance in capillary evaporation governed by the kinetic theory has remained poorly understood. Here we report experimental studies of the kinetic-limited water capillary evaporation in 2-D hydrophilic nanochannels. A novel hybrid nanochannel design is employed to guarantee sufficient water supply to the liquid/vapor evaporation interface and to enable precise evaporation rate measurements. We study the effects of confinement (16 ~ 105nm), temperature (20 ~ 40 °C), and relative humidity (0% ~ 60%) on the evaporation rate and the evaporation coefficient. A maximum evaporation flux of 21287 micron/s is obtained in 16-nm nanochannels at 40°C and RH =0%, which corresponds to a heat flux of 4804 W/cm°. The evaporation coefficient is found to be independent on geometrical confinement, but shows a clear dependence on temperature, decreasing from 0.55 at 20°C to 0.5 at 40 °C. These findings have implications for understanding heat and mass transport in nanofluidic devices and porous media, and shed light on further development of evaporation-based technologies for thermal management, membrane purification and lab-on-a-chip devices. The work is supported by the American Chemical Society Petroleum Research Fund (ACS PRF # 54118-DNI7) and the Faculty Startup Fund (Boston University, USA).

  5. Flow Analysis on a Limited Volume Chilled Water System

    SciTech Connect

    Zheng, Lin

    2012-07-31

    LANL Currently has a limited volume chilled water system for use in a glove box, but the system needs to be updated. Before we start building our new system, a flow analysis is needed to ensure that there are no high flow rates, extreme pressures, or any other hazards involved in the system. In this project the piping system is extremely important to us because it directly affects the overall design of the entire system. The primary components necessary for the chilled water piping system are shown in the design. They include the pipes themselves (perhaps of more than one diameter), the various fitting used to connect the individual pipes to form the desired system, the flow rate control devices (valves), and the pumps that add energy to the fluid. Even the most simple pipe systems are actually quite complex when they are viewed in terms of rigorous analytical considerations. I used an 'exact' analysis and dimensional analysis considerations combined with experimental results for this project. When 'real-world' effects are important (such as viscous effects in pipe flows), it is often difficult or impossible to use only theoretical methods to obtain the desired results. A judicious combination of experimental data with theoretical considerations and dimensional analysis are needed in order to reduce risks to an acceptable level.

  6. Sustainable Water and Agricultural Land Use in the Guanting Watershed under Limited Water Resources

    NASA Astrophysics Data System (ADS)

    Wechsung, F.; Möhring, J.; Otto, I. M.; Wang, X.; Guanting Project Team

    2012-04-01

    The Yongding River System is an important water source for the northeastern Chinese provinces Shanxi, Hebei, Beijing, and Tianjin. The Guanting Reservoir within this river system is one of the major water sources for Beijing, which is about 70 km away. Original planning assumed a discharge of 44 m3/s for the reservoir, but the current mean discharge rate is only about 5 m3/s; there is often hardly any discharge at all. Water scarcity is a major threat for the socio-economic development of the area. The situation is additionally aggravated by climate change impacts. Typical upstream-downstream conflicts with respect to water quantity and quality requests are mixed up with conflicts between different sectors, mainly mining, industry, and agriculture. These conflicts can be observed on different administrative levels, for example between the provinces, down to households. The German-Chinese research project "Sustainable water and agricultural land use in the Guanting Watershed under limited water resources" investigates problems and solutions related to water scarcity in the Guanting Catchment. The aim of the project is to create a vulnerability study in order to assess options for (and finally achieve) sustainable water and land use management in the Guanting region. This includes a comprehensive characterization of the current state by gap analysis and identification of pressures and impacts. The presentation gives an overview of recent project results regarding regionalization of global change scenarios and specification for water supply, evaluation of surface water quantity balances (supply-demand), evaluation of the surface water quality balances (emissions-impact thresholds), and exploration of integrative measurement planning. The first results show that climate in the area is becoming warmer and drier which leads to even more dramatically shrinking water resources. Water supply is expected to be reduced between one and two thirds. Water demand might be

  7. Nitrogen limited biobarriers remove atrazine from contaminated water: laboratory studies.

    PubMed

    Hunter, William J; Shaner, Dale L

    2009-01-07

    Atrazine is one of the most frequently used herbicides. This usage coupled with its mobility and recalcitrant nature in deeper soils and aquifers makes it a frequently encountered groundwater contaminant. We formed biobarriers in sand filled columns by coating the sand with soybean oil; after which, we inoculated the barriers with a consortium of atrazine-degrading microorganisms and evaluated the ability of the barriers to remove atrazine from a simulated groundwater containing 1 mg L(-1) atrazine. The soybean oil provided a carbon rich and nitrogen poor substrate to the microbial consortium. Under these nitrogen-limiting conditions it was hypothesized that bacteria capable of using atrazine as a source of nitrogen would remove atrazine from the flowing water. Our hypothesis proved correct and the biobarriers were effective at removing atrazine when the nitrogen content of the influent water was low. Levels of atrazine in the biobarrier effluents declined with time and by the 24th week of the study no detectable atrazine was present (limit of detection<0.005 mg L(-1)). Larger amounts of atrazine were also removed by the biobarriers; when biobarriers were fed 16.3 mg L(-1) atrazine 97% was degraded. When nitrate (5 mg L(-1) N), an alternate source of nitrogen, was added to the influent water the atrazine removal efficiency of the barriers was reduced by almost 60%. This result supports the hypothesis that atrazine was degraded as a source of nitrogen. Poisoning of the biobarriers with mercury chloride resulted in an immediate and large increase in the amount of atrazine in the barrier effluents confirming that biological activity and not abiotic factors were responsible for most of the atrazine degradation. The presence of hydroxyatrazine in the barrier effluents indicated that dehalogenation was one of the pathways of atrazine degradation. Permeable barriers might be formed in-situ by the injection of innocuous vegetable oil emulsions into an aquifer or sandy soil

  8. Sub-annual Fluctuations in Water Sources Utilised by Mediterranean RiparianTrees Determined Through Highly Resolved Oxygen Isotope Analysis of Tree-ring Cellulose

    NASA Astrophysics Data System (ADS)

    Sargeant, C. I.; Singer, M. B.

    2014-12-01

    The sensitivity of trees to water availability within their rooting zones is a major determinant of tree and forest health. Yet, we have a poor understanding of subterranean water availability and its fluctuations due to climate. Such shortcomings limit our ability to predict how climatic variability will impact water availability to trees, and corresponding forest health. Understanding of water partitioning within the 'critical zone' of riparian areas are particularly lacking, especially in the vulnerable Mediterranean climate regimes. A substantial body of research uses isotope dendrochronology to assess riparian forest-water relations at annual (tree-ring) timescales, which integrate variability in seasonal hydrology. However, the sub-annual variations in water availability have been largely overlooked, which may have important ramifications for riparian ecohydrology. We present a new method for determining the sub-annual hydrologic variability within a floodplain forest using two co-occurring Mediterranean tree species along the Rhône River, southern France. We conducted oxygen isotope (δ18O) analysis of cellulose for 11 microslices within each tree ring to detect sub-annual patterns in δ18O that reflect the variability in hydrological partitioning. We back-calculated the seasonal time series of source waters used by the trees via a mechanistic model. Differences in rooting between the species allow us to constrain fluctuations in water availability and use between the vadose and phreatic zones. The two different species of streamside trees use distinct water sources and their seasonal patterns of water use are also fundamentally different. We develop strong links between these sub-annual patterns of δ18O signatures and the climatic characteristics of the hydrological year. We also present isotopic analyses of source waters from the vadose and phreatic zones, precipitation, and the Rhône to bolster our interpretations of water partitioning. This research

  9. The dynamics of annual carbon allocation to wood in European forests is consistent with a combined source-sink limitation of growth.

    NASA Astrophysics Data System (ADS)

    Guillemot, Joannès; Martin-StPaul, Nicolas K.; Dufrêne, Eric; François, Christophe; Soudani, Kamel; Ourcival, Jean-Marc; Leadley, Paul; Delpierre, Nicolas

    2015-04-01

    The extent to which forest growth is limited by carbon (C) supply (source control) or by cambial activity (sink control) will strongly determines the responses of trees to global changes. However, the physiological processes responsible for the limitation of forest growth are still under debate. The aim of this study was i) to evaluate the key drivers of the annual carbon allocation to wood along large soil and climate regional gradients in four tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex and Picea abies) ii) to implement the identified key drivers in a new C allocation scheme within the CASTANEA terrestrial biosphere model (TBM). Combining field measurements and process-based simulations at 49 sites (931 site-years), our analyses revealed that the inter-site variability in C allocation to wood was predominantly driven by an age-related decline. The direct control of temperature or water stress on sink activity (i.e. independently from their effects on C supply) exerted a strong influence on the annual woody growth in all the species considered, including deciduous temperate species. The lagged effect of the past environment conditions was a significant driver of the annual C allocation to wood. Carbon supply appeared to strongly limit growth only in deciduous temperate species. Our study supports the premise that European forest growth is under a complex panel of source- and sink- limitations, contradicting the simple source control implemented in most TBMs. The implementation of these combined forest growth limitations in the CASTANEA model significantly improved its performance when evaluated against independent stand growth data at the regional scale (mainland France, >10000 plots). We finally discuss how the sink imitation affects the CASTANEA simulated projections of forest productivity along the 21th century, especially with respect to the expected fertilizing effect of increasing atmospheric

  10. Annual summary of ground-water conditions in Arizona, spring 1984 to spring 1985

    USGS Publications Warehouse

    ,

    1986-01-01

    In arid and semiarid regions such as Arizona, the availability of adequate water supplies has a significant influence on the type and extent of economic development. About two-thirds of the water used in the State is groundwater. The nature and extent of the groundwater reservoirs must be known for proper management of this valuable resource. The U.S. Geological Survey, in cooperation with the State of Arizona, has conducted a program of groundwater studies in Arizona since 1939. The primary purposes of these studies are to define the amount, location, and quality of the groundwater resources of Arizona and to monitor the effects of large-scale development of the groundwater supplies. The program includes the collection, compilation, and analysis of the geologic and hydrologic data necessary to evaluate the groundwater resources of the State. The basic hydrologic data are in computer storage and are available to the public. Since 1974, a major thrust of the program has been to inventory the groundwater conditions in the 68 groundwater areas of the State. Several selected groundwater areas are studied each year; water levels are measured annually in a statewide observation well network, many groundwater samples are collected and analyzed annually, and groundwater pumpage is computed for most of the areas. As of July 1985, reports had been published for 56 of the 68 groundwater areas. Data collected in the groundwater areas include information on selected wells, water level measurements, and water samples for chemical analysis. The data for each of the selected groundwater areas are analyzed, and the results are published in map form. Typically, the maps show depth to water; change in water levels; altitude of the water level; and quality of water data, such as specific conductance, dissolved solids, and fluoride. (Lantz-PTT)

  11. [The hygienic situation of the central drinking water supply in the former East Germany--an evaluation of the annual reports on water hygiene from 1984 to 1989].

    PubMed

    Schlosser, F U; Schulze, E

    1991-12-01

    In the former GDR an annual report on the situation in the field of communal hygiene had to be elaborated and submitted to the minister of public health. One part of this was the report on the hygienic situation in water supply, worked out by the Reference Laboratory for Water Hygiene in Bad Elster. After the political changes in autumn 1989 it became possible to analyse these reports as a whole. In this paper the reports from 1984 to 1989 are interpreted. The results of the laboratory measurements and field controls by the State Sanitary Inspectorates are shown in 17 graphics and compared to the bacteriological and chemical limits in drinking water standards. Special issue is drawn on the estimation of the number of inhabitants concerned by reduced drinking-water quality or any hazardous situations. The special problems of the different districts are compared in some graphics. The hygienic safety of the central drinking-water supply units is assessed basing on the results of the field controls by the State Sanitary Inspectorate. The Sanitation of the central drinking-water supply facilities in the new federal countries of the FRG is connected with the solution of a variety of technological problems, particularly the improvement of the water treatment techniques and the restoration of the pipe systems. The use of surface waters from extremely polluted rivers generates a high hygienic risk and requires the sanitation of the rivers. The high number of existing protection zones in the catchment areas for drinking-water is a valuable precondition to ensure the hygienic safety of the drinking-water supply in the new federal countries.

  12. Optimal crop selection and water allocation under limited water supply in irrigation

    NASA Astrophysics Data System (ADS)

    Stange, Peter; Grießbach, Ulrike; Schütze, Niels

    2015-04-01

    Due to climate change, extreme weather conditions such as droughts may have an increasing impact on irrigated agriculture. To cope with limited water resources in irrigation systems, a new decision support framework is developed which focuses on an integrated management of both irrigation water supply and demand at the same time. For modeling the regional water demand, local (and site-specific) water demand functions are used which are derived from optimized agronomic response on farms scale. To account for climate variability the agronomic response is represented by stochastic crop water production functions (SCWPF). These functions take into account different soil types, crops and stochastically generated climate scenarios. The SCWPF's are used to compute the water demand considering different conditions, e.g., variable and fixed costs. This generic approach enables the consideration of both multiple crops at farm scale as well as of the aggregated response to water pricing at a regional scale for full and deficit irrigation systems. Within the SAPHIR (SAxonian Platform for High Performance IRrigation) project a prototype of a decision support system is developed which helps to evaluate combined water supply and demand management policies.

  13. Established native perennial grasses out-compete an invasive annual grass regardless of soil water and nutrient availability

    Treesearch

    Christopher M. McGlone; Carolyn Hull Sieg; Thomas E. Kolb; Ty Nietupsky

    2012-01-01

    Competition and resource availability influence invasions into native perennial grasslands by nonnative annual grasses such as Bromus tectorum. In two greenhouse experiments we examined the influence of competition, water availability, and elevated nitrogen (N) and phosphorus (P) availability on growth and reproduction of the invasive annual grass B. tectorum and two...

  14. 12 CFR 226.55 - Limitations on increasing annual percentage rates, fees, and charges.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Applicable to Credit Card Accounts and Open-End Credit Offered to College Students § 226.55 Limitations on... required to be disclosed under § 226.6(b)(2)(ii), (b)(2)(iii), or (b)(2)(xii) on a credit card account under an open-end (not home-secured) consumer credit plan. (b) Exceptions. A card issuer may increase an...

  15. 12 CFR 226.55 - Limitations on increasing annual percentage rates, fees, and charges.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Applicable to Credit Card Accounts and Open-End Credit Offered to College Students § 226.55 Limitations on... required to be disclosed under § 226.6(b)(2)(ii), (b)(2)(iii), or (b)(2)(xii) on a credit card account under an open-end (not home-secured) consumer credit plan. (b) Exceptions. A card issuer may increase an...

  16. The annual cycle of stratospheric water vapor in a general circulation model

    NASA Technical Reports Server (NTRS)

    Mote, Philip W.

    1995-01-01

    The application of general circulation models (GCM's) to stratospheric chemistry and transport both permits and requires a thorough investigation of stratospheric water vapor. The National Center for Atmospheric Research has redesigned its GCM, the Community Climate Model (CCM2), to enable studies of the chemistry and transport of tracers including water vapor; the importance of water vapor to the climate and chemistry of the stratosphere requires that it be better understood in the atmosphere and well represented in the model. In this study, methane is carried as a tracer and converted to water; this simple chemistry provides an adequate representation of the upper stratospheric water vapor source. The cold temperature bias in the winter polar stratosphere, which the CCM2 shares with other GCM's, produces excessive dehydration in the southern hemisphere, but this dry bias can be ameliorated by setting a minimum vapor pressure. The CCM2's water vapor distribution and seasonality compare favorably with observations in many respects, though seasonal variations including the upper stratospheric semiannual oscillation are generally too small. Southern polar dehydration affects midlatitude water vapor mixing ratios by a few tenths of a part per million, mostly after the demise of the vortex. The annual cycle of water vapor in the tropical and northern midlatitude lower stratosphere is dominated by drying at the tropical tropopause. Water vapor has a longer adjustment time than methane and had not reached equilibrium at the end of the 9 years simulated here.

  17. Evaluation of intra-annual variation in U.S. Geological Survey National Water Quality Assessment ground water quality data.

    PubMed

    Rosen, Michael R; Voss, Frank D; Arufe, Jorge A

    2008-01-01

    Assessment of ground-water quality trends under the U.S. Geological Survey National Water-Quality Assessment Program (NAWQA) included the analysis of samples collected on a quarterly basis for 1 yr between 2001 and 2005. The purpose of this quarterly sampling was to test the hypothesis that variations in the concentration of water-quality parameters of selected individual wells could demonstrate that the intra-annual variation was greater or less than the decadal changes observed for a trend network. Evaluation of more than 100 wells over this period indicates that 1 yr of quarterly sampling is not adequate to address the issue of intra-annual variation because variations seem to be random and highly variable between different wells in the same networks and among networks located in different geographical areas of the USA. In addition, the data from only 1 yr makes it impossible to assess whether variations are due to univariate changes caused by land use changes, hydrologic variations due to variable recharge, or variations caused by ground-water pumping. These data indicate that funds allocated to this activity can be directed to the collection of more effective trend data, including age dating of all wells in the NAWQA network using multiple techniques. Continued evaluation of data and updating of monitoring plans of the NAWQA program is important for maintaining relevance to national goals and scientific objectives.

  18. Does leaf water efficiency vary among eucalypts in water-limited environments?

    PubMed

    Hatton, Tom; Reece, Peter; Taylor, Peter; McEwan, Kerryn

    1998-01-01

    There is a need to generalize water use behavior of eucalypts to facilitate bioengineering and landscape remediation programs in a wide range of Australian environments. A critical question can be stated as a null hypothesis: tree water use per unit leaf area (leaf efficiency) is independent of eucalypt species. This is implicitly equivalent to the hydrological equilibrium hypothesis that states that leaf area is a function of climate, at least in cases where transpiration and growth are limited by soil water. Failure to reject this null hypothesis simplifies (a) the selection of tree species for water balance management, (b) the generation of regional-scale expectations of leaf area index, and (c) the estimation (monitoring) of the effectiveness of plantations in controlling site water balance. The hypothesis was tested with tree water use data collected in natural multi-species stands across Australia, including sites in the wet-dry season tropical woodlands of the Northern Territory, the Mediterranean climate forests of Western Australia, and a woodland system in southern New South Wales receiving an even distribution of rainfall throughout the year. We also tested the hypothesis in a multi-species tree plantation growing on a saline gradient. In each case, we could not reject the hypothesis of constant leaf efficiency among eucalypts. In every case there was a common, strong, linear relationship among tree leaf area and mean daily water use by all tree species in a sample. Single factor (species) analysis of variance did not detect significant differences between leaf water efficiencies of species. For the jarrah forest (Eucalyptus marginata J. Donn ex Sm., E. calophylla R. Br. ex Lindl.), the null hypothesis held in both spring (wet) and autumn (dry) conditions. The null hypothesis held in the mixed species woodland of New South Wales (E. macrorhynca F.J. Muell. ex Benth., E. blakelyi Maiden., E. polyanthemos Schauer.) under summer and autumn conditions, and

  19. A review of permissible limits of drinking water.

    PubMed

    Kumar, Manoj; Puri, Avinash

    2012-01-01

    Water is one of the prime necessities of life. We can hardly live for a few days without water. In a man's body, 70-80% is water. Cell, blood, and bones contain 90%, 75%, and 22% water, respectively. The general survey reveals that the total surface area of earth is 51 crore km(2) out of which 36.1 crore km(2) is covered sea. In addition to this, we get water from rivers, lakes, tanks, and now on hills. In spite of such abundance, there is a shortage of soft water in the world. Physicochemical parameter of any water body plays a very important role in maintaining the fragile ecosystem that maintains various life forms. Present research paper deals with various water quality parameter, chlorides, dissolved oxygen, total iron, nitrate, water temperature, pH, total phosphorous, fecal coli form bacteria, and adverse effect of these parameters on human being.

  20. A review of permissible limits of drinking water

    PubMed Central

    Kumar, Manoj; Puri, Avinash

    2012-01-01

    Water is one of the prime necessities of life. We can hardly live for a few days without water. In a man's body, 70-80% is water. Cell, blood, and bones contain 90%, 75%, and 22% water, respectively. The general survey reveals that the total surface area of earth is 51 crore km2 out of which 36.1 crore km2 is covered sea. In addition to this, we get water from rivers, lakes, tanks, and now on hills. In spite of such abundance, there is a shortage of soft water in the world. Physicochemical parameter of any water body plays a very important role in maintaining the fragile ecosystem that maintains various life forms. Present research paper deals with various water quality parameter, chlorides, dissolved oxygen, total iron, nitrate, water temperature, pH, total phosphorous, fecal coli form bacteria, and adverse effect of these parameters on human being. PMID:23112507

  1. 1995 annual water monitoring report, LEHR environmental restoration, University of California at Davis

    SciTech Connect

    Stewart, D.L.; Smith, R.M.; Sauer, D.R.

    1996-03-01

    This 1995 Annual Water Monitoring Report presents analytical data collected between January and December 1995 at the Laboratory for Energy-Related Health Research (LEHR) located at the University of California (UC), Davis. This report has been prepared by Pacific Northwest National Laboratory in compliance with the Water Monitoring Plan for the LEHR site, which contains the sample collection, analysis, and quality assurance/quality control procedures and reporting requirements. Water monitoring during 1995 was conducted in conjunction with the Remedial Investigation/Feasibility Study currently being implemented at the LEHR site as part of a US Department of Energy (DOE)-sponsored environmental restoration program. Based on a review of historical groundwater monitoring data compiled since the fall of 1990, the list of analytes included in the program was reduced and the schedule for analyzing the remaining analytes was revised. The revision was implemented for the first time in the summer monitoring period. Analytes eliminated from the program were those that were (1) important for establishing baseline groundwater chemistry (alkalinity, anions, Eh, total organic carbon, and chemical oxygen demand); (2) important for establishing sources of contamination; (3) not detected in water samples or not from the LEHR site; and (4) duplicates of another measurement. Reductions in the analytical schedule were based on the monitoring history for each well; the resultant constituents of concern list was developed for individual wells. Depending on its importance in a well, each analyte was analyzed quarterly, semi-annually, or annually. Pollutants of major concern include organic compounds, metals, and radionuclides.

  2. Upscaling of annual mean and dynamics of water table depth in German organic soils

    NASA Astrophysics Data System (ADS)

    Bechtold, Michel; Tiemeyer, Bärbel; Belting, Susanne; Laggner, Andreas; Leppelt, Thomas; Frahm, Enrico; Freibauer, Annette

    2013-04-01

    Water table depth is the key parameter controlling the fluxes of CO2, CH4 and N2O from organic soils (peatlands and other organic soils). Therefore, a good estimation of the spatial distribution of water table depth is crucial in any upscaling approach for these greenhouse gases (GHGs). It is further the prerequisite to assess the effects of re-wetting measures. There are attempts to obtain maps of water table depth at large scales (e.g. national or continental) by using process-based hydrological model concepts. However, major problem of the process-based approach is the representation of the water management (ditches, tile drains, pumping and weir management), which is at the best known spatially just for the ditch patterns. Thus, this approach is hardly applicable to the diversely-drained and -used organic soils in central Europe. Here, we present an alternative, data-driven approach for upscaling annual mean and dynamics of water table depth in organic soils. Groundwater level data of a unique dataset from about 60 peatlands, 1100 dipwells and around 8000 annual data sets, is the basis of this approach. Time series were used to calculate long-term annual means, average annual amplitudes and ponding durations. In case of continuous observations, shape parameters of the annual frequency distribution of water table depths were calculated. For each well, numerous site characteristics were collected as possible explanatory variables. This collection was restricted to nationally-available data. For each dipwell, land use is taken from official land use maps (German database ATKIS), and the soil type from the national geological map (1:200.000). In case of reliable site information, maps were corrected accordingly. Additionally, from these maps, topological indicators such as the ditch distance and density, the distance to the edge of the peatland and the peatland area within different buffers were calculated. Meteorological data (precipitation, potential

  3. Life history traits in selfing versus outcrossing annuals: exploring the 'time-limitation' hypothesis for the fitness benefit of self-pollination

    PubMed Central

    Snell, Rebecca; Aarssen, Lonnie W

    2005-01-01

    Background Most self-pollinating plants are annuals. According to the 'time-limitation' hypothesis, this association between selfing and the annual life cycle has evolved as a consequence of strong r-selection, involving severe time-limitation for completing the life cycle. Under this model, selection from frequent density-independent mortality in ephemeral habitats minimizes time to flower maturation, with selfing as a trade-off, and / or selection minimizes the time between flower maturation and ovule fertilization, in which case selfing has a direct fitness benefit. Predictions arising from this hypothesis were evaluated using phylogenetically-independent contrasts of several life history traits in predominantly selfing versus outcrossing annuals from a data base of 118 species distributed across 14 families. Data for life history traits specifically related to maturation and pollination times were obtained by monitoring the start and completion of different stages of reproductive development in a greenhouse study of selfing and outcrossing annuals from an unbiased sample of 25 species involving five pair-wise family comparisons and four pair-wise genus comparisons. Results Selfing annuals in general had significantly shorter plant heights, smaller flowers, shorter bud development times, shorter flower longevity and smaller seed sizes compared with their outcrossing annual relatives. Age at first flower did not differ significantly between selfing and outcrossing annuals. Conclusions This is the first multi-species study to report these general life-history differences between selfers and outcrossers among annuals exclusively. The results are all explained more parsimoniously by selection associated with time-limitation than by selection associated with pollinator/mate limitation. The shorter bud development time reported here for selfing annuals is predicted explicitly by the time-limitation hypothesis for the fitness benefit of selfing (and not by the

  4. Irrigation in water restricted regions: Managing water use efficiency with limited available water

    USDA-ARS?s Scientific Manuscript database

    Political and social pressures to increase water-use efficiency in agriculture from plant to regional scales are reaching critical levels. A region where these pressures have been extremely acute is most semi-arid parts of Texas where reliable crop production is possible only through irrigation. Re...

  5. Resolving inter-annual terrestrial water storage variations using microwave-based surface soil moisture retrievals

    USDA-ARS?s Scientific Manuscript database

    Due to their shallow vertical support, remotely-sensed surface soil moisture retrievals are commonly regarded as being of limited value for water budget applications requiring the characterization of temporal variations in total terrestrial water storage (S). However, advances in our ability to esti...

  6. Evaluate Factors Limiting Columbia River Gorge Chum Salmon Populations : FY2001 Annual Report.

    SciTech Connect

    Hoffman, Thomas A.

    2001-12-01

    Juvenile and adult chum salmon were monitored in fiscal year 2001 to continue evaluating factors limiting production. Total adult salmon caught (in weirs or by carcass surveys) in Hardy Creek and Hamilton Springs in 2000 was 25 and 130 fish, respectively. Fifty-two fish captured in the main stem Columbia River, Hamilton Springs, Hardy Creek, or Bonneville Dam were implanted with radio tags and tracked with an array of fixed aerials and underwater antennae. Males tended to move greater distances than females. Population estimates in Hardy Creek and Hamilton Springs were 37{+-}2 and 157{+-}5, respectively. Chum smolt emigration began in Hamilton Springs 25 February 2001 and 2 March 2001 in Hardy Creek. Total catches in Hardy Creek and Hamilton Springs were 2,955 and 14,967, respectively. Population abundance estimates were 11,586{+-}1,836 in Hardy Creek and 84,520{+-}9,283 in Hamilton Springs.

  7. Photodegradation of Leaf Litter in Water-Limited Ecosystems

    NASA Astrophysics Data System (ADS)

    Cory, R. M.; Powers, H.; McDowell, N.; Rahn, T.

    2008-12-01

    The longstanding view of terrestrial decomposition holds that heterotrophic respiration drives release of CO2, but recent studies, such as Austin and Vivanco (2006) have shown that in water-limited environments, photochemical decomposition of leaf litter may be equally or more effective than microbial decomposition. Although initial studies have concluded that photochemical degradation can be important in some environments, it has been difficult to quantify and the oxidative mechanisms involved remain unknown. Thus, the objectives of our study were to (1) quantify the CO2 emitted during photochemical degradation of leaf litter and (2) use the stable isotopic signatures of evolved CO2 to elucidate pathways of production. Emitted CO2 and its isotopic signature were measured using a tunable diode laser (TDL) to assess the pool of photochemically-labile plant matter (δ13C-CO2) in a given sample and to assess the source of the oxygen (δ18O-CO2). We quantified the photochemical release of CO2 and its isotopic signature from dried leaf litter of 10 tree and grass species prevalent in major biotic zones of New Mexico. The cumulative CO2 released upon exposure of 0.1-0.3 g of dried leaf litter to three hours of simulated sunlight ranged from 8-25 mg CO2-C g-1 dried litter, corresponding to 1-2% mass loss. Generally, the δ13C-CO2 was more depleted (4-7 ± 2 per mil) than the average δ13C of the respective leaf litter sample. The δ18O-CO2 evolved is approximately equal to δ18O of atmospheric O2, suggesting that the oxidation mechanism involves direct reaction with atmospheric O2.

  8. Inter- annual variability of water vapor over an equatorial coastal station using Microwave Radiometer observations.

    NASA Astrophysics Data System (ADS)

    Renju, Ramachandran Pillai; Uma, K. N.; Krishna Moorthy, K.; Mathew, Nizy; Raju C, Suresh

    The south-western region of the Indian peninsula is the gateway of Indian summer monsoon. This region experiences continuous monsoon rain for a longer period of about six months from June to November. The amount of water vapor variability is one of the important parameters to study the onset, active and break phases of the monsoon. Keeping this in view, a multi-frequency Microwave Radiometer Profiler (MRP) has been made operational for continuous measurements of water vapor over an equatorial coastal station Thiruvananthapuram (8.5(°) N, 76.9(°) E) since April 2010. The MRP estimated precipitable water vapor (PWV) for different seasons including monsoon periods have been evaluated by comparing with the collocated GPS derived water vapor and radiosonde measurements. The diurnal, seasonal and inter annual variation of water vapor has been studied for the last four years (2010-2013) over this station. The significant diurnal variability of water vapor is found only during the winter and pre-monsoon periods (Dec -April). The vertical distribution of water vapour is studied in order to understand its variability especially during the onset of monsoon. During the building up of south-west monsoon, the specific humidity increases to ˜ 10g/kg in the altitude range of 4-6 km and consistently maintained it throughout the active spells and reduces to below 2g/kg during break spells of monsoon. The instrument details and the results will be presented.

  9. Determination of water environment standards based on water quality criteria in China: Limitations and feasibilities.

    PubMed

    Wang, Tieyu; Zhou, Yunqiao; Bi, Cencen; Lu, Yonglong; He, Guizhen; Giesy, John P

    2017-07-01

    There is a need to formulate water environment standards (WESs) from the current water quality criteria (WQC) in China. To this end, we briefly summarize typical mechanisms applied in several countries with longer histories of developing WESs, and three limitations to formulating WESs in China were identified. After analyzing the feasibility factors including economic development, scientific support capability and environmental policies, we realized that China is still not ready for a complete change from its current nation-wide unified WES system to a local-standard-based system. Thus, we proposed a framework for transformation from WQC to WESs in China. The framework consists of three parts, including responsibilities, processes and policies. The responsibilities include research authorization, development of guidelines, and collection of information, at both national and local levels; the processes include four steps and an impact factor system to establish water quality standards; and the policies include seven specific proposals. Copyright © 2016. Published by Elsevier B.V.

  10. Derivation and implementation of an annual limit on intake and a derived air concentration value for uranium mill tailings.

    PubMed

    Reif, R H; Andrews, D W

    1995-06-01

    Monitoring workers and work areas at the Department of Energy Uranium Mill Tailings Remedial Action Project sites is complex because all radionuclides in the 238U and 235U decay chains may be present in an airborne uranium mill tailings matrix. Previous monitoring practices involved isotopic analysis of the air filter to determine the activity of each radionuclide of concern and comparing the results to the specified derived air concentration. The annual limit on intake and derived air concentration values have been derived here for the uranium mill tailings matrix to simplify the procedure for evaluation of air monitoring results and assessment of the need for individual monitoring. Implementation of the derived air concentration for uranium mill tailings involves analyzing air samples for long-lived gross alpha activity and comparing the activity concentration to the derived air concentration. Health physics decisions regarding assessment of airborne concentrations is more cost-effective because isotopic analysis of air samples is not necessary.

  11. Evaluate Factors Limiting Columbia River Gorge Chum Salmon Populations; FY 2002 Annual Report.

    SciTech Connect

    Uusitalo, Nancy M.

    2003-01-30

    Adult and juvenile chum salmon were monitored from October 2001 through September 2002 to evaluate factors limiting production. In 2001, 6 and 69 adult chum salmon were captured in the Hardy Creek and Hamilton Springs weirs, respectively. In 2001, 285 and 328 chum salmon carcasses were recovered during spawning ground surveys in Hardy Creek and Hamilton Springs, respectively. Twenty-eight fish captured in the mainstem Columbia River, Hamilton Springs, and Hardy Creek were implanted with radio tags and tracked via an array of fixed aerial, underwater antennas and a mobile tracking unit. Using the Area-Under-the-Curve program population estimates of adult chum salmon were 835 in Hardy Creek and 617 in Hamilton Springs. Juvenile chum salmon migration was monitored from March-June 2002. Total catches for Hardy Creek and Hamilton Springs were 103,315 and 140,220, respectively. Estimates of juvenile chum salmon emigration were 450,195 ({+-}21,793) in Hardy Creek and 561,462 ({+-}21,423) in Hamilton Springs.

  12. Generalized estimates from streamflow data of annual and seasonal ground-water-recharge rates for drainage basins in New Hampshire

    USGS Publications Warehouse

    Flynn, Robert H.; Tasker, Gary D.

    2004-01-01

    This report presents regression equations to estimate generalized annual and seasonal ground-water-recharge rates in drainage basins in New Hampshire. The ultimate source of water for a ground-water withdrawal is aquifer recharge from a combination of precipitation on the aquifer, ground-water flow from upland basin areas, and infiltration from streambeds to the aquifer. An assessment of ground-water availability in a basin requires that recharge rates be estimated under `normal' conditions and under assumed drought conditions. Recharge equations were developed by analyzing streamflow, basin characteristics, and precipitation at 55 unregulated continuous record stream-gaging stations in New Hampshire and in adjacent states. In the initial step, streamflow records were analyzed to estimate a series of annual and seasonal ground-water-recharge components of streamflow in each drainage basin evaluated in this study. Regression equations were then developed relating the series of annual and seasonal ground-water-recharge values to the corresponding series of annual and seasonal precipitation values as determined at the centroid of each drainage basin. This resulted in one equation for each of the 55 basins for each of the four seasonal periods and the annual period, or a total of 275 regression equations. Average annual and seasonal precipitation data for 1961-90 were then used to compute a set of normalized ground-water-recharge values that reflected the long-term average annual and seasonal variations (normalized) and mean recharge characteristics of each drainage basin. Ordinary-least-squares regression was applied in the process of selecting 10 out of 93 possible basin and climatic characteristics for further testing in the development of the equations for computing the generalized estimate of annual and seasonal ground-water recharge based on the set of normalized recharge values. Generalized-least-squares regression was used for the final parameter estimation and

  13. Floatabilities of treated coal in water at room temperature. Annual topical report, September 1992--August 1993

    SciTech Connect

    Kwon, K.C.; Rohrer, R.L.; Lai, R.W.; Finseth, D.H.

    1993-12-31

    This report contains a research paper entitled ``Floatability of Treated Coal in Water at Room Temperature.`` Experimental data on equilibrium adsorption loadings of probe compounds on coal, and flotation of raw coals as well as treated coal were obtained, using Illinois No. 6 coal (PSOC-1539), Adaville No. 1 coal (PSOC-1544), Wyodak coal (PSOC-1545) and Pittsburgh No. 8 coal (PSOC-1549). The raw data of this Annual Topical Report are also available in the Quarterly Progress Report for the period April--June 1993 and the Quarterly Progress Report July--September 1993.

  14. Inter-annual precipitation fluctuations alter the responses of above- and belowground biomass to water and N enrichment

    NASA Astrophysics Data System (ADS)

    Kong, D. L.; Lü, X. T.; Jiang, L. L.; Wu, H. F.; Miao, Y.; Kardol, P.

    2013-08-01

    Water availability has profound effects on plant growth and productivity in temperate and semi-arid grasslands. However, it remains unclear how variation of inter-annual precipitation by extreme rainfall events will alter the aboveground and belowground responses of plants, and how these responses may be contingent on N availability. In this study, we examined the interactive effects of inter-annual precipitation variation and N addition on aboveground and live fine root biomass of a semi-arid grassland in northern China for two consecutive years (2007 and 2008). Inter-annual variation in precipitation resulting mainly from the occurrence of extreme rainfall events in 2008 significantly affected above- and belowground plant biomass responses to water addition. In addition, variation of inter-annual precipitation by this extreme rainfall event suppressed plant responses to nitrogen addition and reduced the interaction effects between water and nitrogen addition. These effects of inter-annual precipitation fluctuation could be attributed to the negative influence of the extreme rainfall event on soil N and water availability, ultimately reducing plant rainfall use efficiency and nitrogen use efficiency. In conclusion, our results suggest ecosystem responses to water and N enrichment could be altered by inter-annual variation of precipitation regime caused by the naturally occurring extreme rainfall events.

  15. Columbia Basin Water Transactions Program (Water Entity); National Fish and Wildlife Foundation, Annual Report 2003.

    SciTech Connect

    National Fish and Wildlife Foundation

    2004-02-01

    Launched in 2002, the Columbia Basin Water Transactions Program (CBWTP) is anticipated to be a five-year effort to test new strategies for enhancing tributary flows. The premise of the CBWTP is that water can most readily be made available for instream flows not by attempting to regulate senior water users but, instead, by acquiring water rights from willing sellers and transferring those rights to instream flows within the prior appropriation framework ('first in time, first in right'). The primary goals for this water initiative included: (1) To implement Action 151 of the NOAA Fisheries 2000 Biological Opinion on the Operation of the Federal Columbia River Power System. (2) To implement Provision A.8 of the Council's 2000 Columbia River Basin Fish and Wildlife Program related to securing water for instream flows. (3) To integrate components of the Northwest Power and Conservation Council's Program and Watershed Assessment process with the NOAA Fisheries 2000 Biological Opinion. (4) To ensure actions taken under the program would be effective, fiscally efficient, and biologically beneficial to fish and wildlife in the region. In the spring of 2002, BPA and a group of water experts selected ten local entities in Washington, Oregon, Idaho, and western Montana with a demonstrated potential to innovate and implement tributary flow improvements. We also selected the National Fish and Wildlife Foundation (NFWF) to serve as the regional entity for this initiative. BPA then set up the funding agreement and scope of work to establish what is now known as the Columbia Basin Water Transactions Program. In FY 2003, BPA provided over $1.5 million in funding to the CBWTP and approved 33 water transactions. In FY 2004, BPA will provide up to $4 million to the project to enhance habitat. Thanks to the dedicated efforts of partners throughout the Basin, the CBWTP is off to a strong start in improving tributary flows in key areas across the region.

  16. Water worlds: characterization, thermal evolution and habitability limitations

    NASA Astrophysics Data System (ADS)

    Noack, Lena; Heistracher, Clemens; Zimov, Nastasia; Hoening, Dennis; Rivoldini, Attilio; Van Hoolst, Tim; Lammer, Helmut; Hendrik Bredehoeft, Jan

    2015-04-01

    Water is necessary for the origin and survival of life like we know it. In the search for life-friendly worlds, water-rich planets therefore seem to be obvious candidates and have attracted increasing attention in the past years. The water layer on such planets could be hundreds of kilometers deep depending on the water content and the evolution of the proto-atmosphere. A deep water layer will likely form high-pressure ice from a specific depth on. We study possible constraints for the habitability of deep water layers and introduce a new habitability classification to be applied to water-rich planets (from about Mars-size to almost Neptune-size planets). A new ocean model has been developed coupled with an interior structure model to infer the depth-dependent thermodynamic properties of high-pressure water and the possible formation of high-pressure ice. We find that the ice layer can be molten from beneath by heat flowing out of the silicate mantle [Noack et al., in review, "Water worlds: how life-friendly is an ocean deeper than on Earth?"], depending amongst others on the thickness of the ocean-ice shell and the mass of the planet. From our results we conclude that water-rich planets with a deep ocean, a large planet mass, a high average density or a small surface temperature are less habitable than a planet with an Earth-like ocean and might not be suitable candidates for the origin of life. Ocean planets, that can be clearly detected as such, contain a large amount of water (to significantly reduce the average density of the planet) and are likely to have a thick high-pressure ice layer which cannot be molten from beneath - these planets might therefore not be habitable.

  17. Using activated carbon to limit herbicide effects to seeded bunchgrass when revegetating annual grass-invaded rangelands

    USDA-ARS?s Scientific Manuscript database

    Revegetation of exotic annual grass-invaded rangelands is challenging as annuals rapidly reinvade after control treatments. The most effective control of exotic annual grass is usually achieved with pre-emergent herbicides, however, species seeded simultaneously with these herbicides will likely ex...

  18. STORM WATER BEST MANAGEMENT PRACTICES: CAPACITIES, CAPABILITIES, AND SOME LIMITATIONS

    EPA Science Inventory

    This presentation will cover the basics of what a storm water best management practices and focus on infiltration-type practices using the example of rain gardens. I will demonstrate how water moves through rain gardens with a simple hydrologic model and discuss ancillary benefit...

  19. Water resources data for Indiana, water year 1993. Water-data report (Annual), 1 October 1992-30 September 1993

    SciTech Connect

    Stewart, J.A.; Keeton, C.R.; Benedict, B.L.; Hammil, L.E.

    1994-05-01

    Water resources data for the 1993 water year for Indiana consist of records of discharge, stage, and water quality of streams and wells; reservoirs stage and currents; and water levels in lakes and wells. This report contains records of discharge for 175 stream-gaging stations, stage for 5 stream stations, 1 sediment station, stage and contents for 1 reservoir, water quality for 3 streams, and water levels for 80 lakes and 94 observation wells.

  20. Water resources data for Indiana, water year 1994. Water-data report (Annual), 1 October 1993-30 September 1994

    SciTech Connect

    Stewart, J.A.; Keeton, C.R.; Benedict, B.L.; Hammil, L.E.

    1995-05-01

    Water resources data for the 1994 water year for Indiana consists of records of discharge, stage, and water quality of streams and wells; reservoirs stage and contents; and water levels in lakes and wells. This report contains records for discharge at 167 stream-gaging stations, stage for 6 stream stations, 1 sediment station, stage and contents for 1 reservoir, water quality for 2 streams, and water levels for 80 lakes and 94 observation wells.

  1. Water resources data for Indiana, water year 1992. Water-data report (Annual), 1 October 1991-30 September 1992

    SciTech Connect

    Stewart, J.A.; Keeton, C.R.; Benedict, B.L.; Hammil, L.E.

    1993-04-01

    Water resources data for the 1992 water year for Indiana consist of records of discharge, stage, and water quality of streams and wells; reservoir stage and contents; and water levels in lakes and wells. The report contains records of discharge for 175 stream-gaging stations, stage for 7 stream stations, 1 sediment station, stage and contents for 1 reservoir, water quality for 3 streams, and water levels for 80 lakes and 94 observation wells.

  2. Estimation of mean annual effective dose through radon concentration in the water and indoor air of Islamabad and Murree.

    PubMed

    Ali, N; Khan, E U; Akhter, P; Khan, F; Waheed, A

    2010-09-01

    Different samples of water, indoor air and soil gas have been collected from Islamabad (33 degrees 38'N, 73 degrees 09'E, altitude of 1760 ft.), the capital of Pakistan and Murree (33 degrees 53'N, 73 degrees 23'E, altitude of 7323 ft.), lying on a geological fault line and are analysed for the estimation of mean effective dose through radon concentrations by using RAD-7, a solid state alpha-detector. The variation of radon concentration in water, indoor air and soil gas in Islamabad region ranges from 25.90-158.40 kBq m(-3), 43.26-97.04 Bq m(-3) and 17.34-72.52 kBq m(-3), having mean values 88.63 kBq m(-3), 70.67 Bq m(-3) and 45.08 kBq m(-3)(,) respectively. It ranges from 1.64-10.20 kBq m(-3), 18.48-42.08 Bq m(-3) and 0.61-3.89 kBq m(-3) with mean values 4.38 kBq m(-3), 28.63 Bq m(-3) and 1.70 kBq m(-3)(,) respectively in Murree and its surroundings. The total mean annual effective doses from water and indoor air of Islamabad and Murree regions are 2.023 and 0.733 mSv a(-1), respectively. These doses are within the recommended limits of the world organisations.

  3. Effect of water availability on leaf water isotopic enrichment in beech seedlings shows limitations of current fractionation models.

    PubMed

    Ferrio, Juan Pedro; Cuntz, Matthias; Offermann, Christine; Siegwolf, Rolf; Saurer, Matthias; Gessler, Arthur

    2009-10-01

    Current models of leaf water enrichment predict that the differences between isotopic enrichment of water at the site of evaporation (Delta(e)) and mean lamina leaf water enrichment (Delta(L)) depend on transpiration rates (E), modulated by the scaled effective length (L) of water isotope movement in the leaf. However, variations in leaf parameters in response to changing environmental conditions might cause changes in the water path and thus L. We measured the diel course of Delta(L) for (18)O and (2)H in beech seedlings under well-watered and water-limited conditions. We applied evaporative enrichment models of increasing complexity to predict Delta(e) and Delta(L), and estimated L from model fits. Water-limited plants showed moderate drought stress, with lower stomatal conductance, E and stem water potential than the control. Despite having double E, the divergence between Delta(e) and Delta(L) was lower in well-watered than in water-limited plants, and thus, L should have changed to counteract differences in E. Indeed, L was about threefold higher in water-limited plants, regardless of the models used. We conclude that L changes with plant water status far beyond the variations explained by water content and other measured variables, thus limiting the use of current evaporative models under changing environmental conditions.

  4. Asotin Creek ISCO Water Sample Data Summary: Water Year 2002, Annual Report 2001-2002.

    SciTech Connect

    Peterson, Stacia

    2003-08-01

    The Pomeroy Ranger District operates 3 automated water samplers (ISCOs) in the Asotin Creek drainage in cooperation with the Asotin Model Watershed. The samplers are located on Asotin Creek: Asotin Creek at the mouth, Asotin Creek at Koch site, and South Fork Asotin Creek above the forks. At the end of Water Year (WY) 2001 we decided to sample from Oct. 1 through June 30 of each water year. This decision was based on the difficulty of obtaining good low flow samples, since the shallow depth of water often meant that instrument intakes were on the bed of the river and samples were contaminated with bed sediments. The greatest portion of suspended sediment is transported during the higher flows of fall and especially during the spring snow runoff period, and sampling the shorter season should allow characterization of the sediment load of the river. The ISCO water samplers collected a daily composite sample of 4 samples per day into one bottle at 6-hour intervals until late March when they were reprogrammed to collect 3 samples per day at 8-hour intervals. This was done to reduce battery use since battery failure had become an ongoing problem. The water is picked up on 24-day cycles and brought to the Forest Service Water Lab in Pendleton, OR. The samples are analyzed for total suspended solids (TSS), conductivity, and turbidity. A total dissolved solids value is estimated based on conductivity. The USGS gage, Asotin Creek at the mouth, No.13335050 has been discontinued and there are no discharge records available for this period.

  5. Annual variations of water vapor in the stratosphere and upper troposphere observed by the Stratospheric Aerosol and Gas Experiment II

    SciTech Connect

    McCormick, M.P.; McMaster, L.R.; Chu, W.P. ); Chiou, E.W.; Larsen, J.C. ); Rind, D. ); Oltmans, S. )

    1993-03-20

    This paper presents a description of the annual variations of water vapor in the stratosphere and the upper troposphere derived from observations of the Stratospheric Aerosol and Gas Experiment II (SAGE II). The altitude-time cross sections exhibit annually repeatable patterns in both hemispheres. The appearance of a yearly minimum in water vapor in both hemispheres at approximately the same time supports the idea of a common source(s) for stratospheric dry air. Annual patterns observed at northern mid-latitudes, like the appearance of a hygropause in winter and the weakening and upward shifting of the hygropause from January to May, agree with in situ balloon observations previously obtained over Boulder and Washington, DC. An increase in water vapor with altitude in the tropics is consistent with methane oxidation in the upper stratosphere to lower mesosphere as a source for water vapor. A poleward gradient is also shown as expected based on a Lagrangian mean circulation. A linear regression analysis using SAGE II data from January 1986 to December 1988 shows that little annual variation occurs in the middle and upper stratosphere with the region of large annual variability near the tropopause. The semi-annual variability is relatively marked at altitudes of 24 and 40 km in the tropics. 30 refs., 4 figs., 1 tab.

  6. 40 CFR 440.43 - Effluent limitations representing the degree of effluent reduction attainable by the application...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... exceeds the annual evaporation, a volume of water equal to the difference between annual precipitation... facility and annual evaporation may be discharged subject to the limitations set forth in paragraph (a) of...

  7. 40 CFR 440.43 - Effluent limitations representing the degree of effluent reduction attainable by the application...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... exceeds the annual evaporation, a volume of water equal to the difference between annual precipitation... facility and annual evaporation may be discharged subject to the limitations set forth in paragraph (a) of...

  8. Lower limits of crop water use in three soil textural classes

    USDA-ARS?s Scientific Manuscript database

    Accurate knowledge of the amount of soil water available for crop use allows better management of limited water supplies. Using neutron scattering, we determined the mean lower limit of field soil water use (LL*F, m**3 m**-3) to a depth of 2.2 m at harvest (three seasons each) of short-season maize...

  9. Response of larch root development to annual changes of water conditions in eastern Siberia

    NASA Astrophysics Data System (ADS)

    Takenaka, Chisato; Miyahara, Mie; Ohta, Takeshi; Maximov, Trofim C.

    2016-06-01

    Eastern Siberia is characterized by continuous permafrost, and has recently been exposed to the effects of climate change. Larch, which is the dominant tree species, has been subject to major environmental changes including fluctuations in soil water content. The purpose of this study was to clarify the responses of mature larch tree roots to changes in soil water conditions. We established a treatment plot in a larch forest, and artificially changed the soil water conditions by covering the ground surface with a vinyl sheet, and from 2004 to 2006 monitored root development through root windows. The vinyl sheet maintained high levels of soil water content, even though the ambient conditions varied from dry in 2004 to wet in 2005 and dry in 2006. In the treatment plot the plants adapted to the wet conditions by decreasing vertical root development. In contrast, roots of plants in the control plot developed to the subsurface layer, even in 2005, and did not develop vertically in 2006 despite the drought. We conclude that larch adapted to the annual changes in soil water content by changing the vertical distribution of roots, and that this reflected a memory effect.

  10. Limiting shear stress and monotonic properties of liquid water

    NASA Astrophysics Data System (ADS)

    Gorshkov, A. I.

    2016-12-01

    Publications in scientific journals in which the authors attempt to experimentally prove that water, the most widespread substance on the Earth, is not a completely classical liquid, have become more frequent recently. This means, first, that water behaves as a solid at very low shear stress, i.e., does not flow, and, second, that the temperature dependences of its different properties are non-monotonic, i.e., possess singularities. We are aware of several such publications [1-5].

  11. Evaporation, transpiration, and ecosystem water use efficiency in a multi-annual sugarcane production system in Hawai’i, USA

    USDA-ARS?s Scientific Manuscript database

    Food and biofuel production will require practices that increase water use efficiency in order to have future sustainability in a water-constrained environment. One possible practice is the use of food and energy crops with multi-annual growing periods, which could reduce bare soil evaporation. We...

  12. Assessment of wildland fire impacts on watershed annual water yield: Analytical framework and case studies in the United States

    Treesearch

    Dennis W. Hallema; Ge Sun; Peter V. Caldwell; Steve Norman; Erika Cohen Mack; Yongqiang Liu; Eric J. Ward; Steve McNulty

    2016-01-01

    More than 50% of water supplies in the conterminous United States originate on forestland or rangeland, and are potentially under increasing stress as a result of larger and more severe wildfires. Little is known however about the long-term impacts of fire on annual water yield, and the role of climate variability within this context. We here propose a framework for...

  13. 25 CFR 171.510 - How does BIA calculate my annual operation and maintenance assessment if supplemental water is...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false How does BIA calculate my annual operation and maintenance assessment if supplemental water is available on the irrigation facility servicing my farm unit? 171.510 Section 171.510 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER IRRIGATION OPERATION AND MAINTENANCE...

  14. Regional annual water yield from forest lands and its response to potential deforestation across the southeastern United States

    Treesearch

    Ge Sun; Steve G. McNulty; J. Lu; Devendra M. Amatya; Y. Liang; R.K. Kolka

    2005-01-01

    Regional water yield at a meso-scale can be estimated as the difference between precipitation input and evapotranspiration output. Forest water yield from the southeastern US varies greatly both in space and time. Because of the hot climate and high evapotranspiration, less than half of the annual precipitation that falls on forest lands is available for stream flow...

  15. Limitation of hardness from thermal water by means of nanofiltration.

    PubMed

    Tonko, Csilla Maria; Kiraly, Andras; Mizsey, Peter; Patzay, Gyorgy; Csefalvay, Edit

    2013-01-01

    Geothermal conditions are extremely favourable in Hungary. Thermal water is accessible in 70% of the territory of the country, with a lowest temperature of 30°C. For energetic purposes, it can be utilized in two different ways: for supplying heat or generating electricity. In relation to utilization, one of the most serious problems derives from the chemical composition of thermal water. The present paper investigates the opportunities of preventing scaling by nanofiltration. Experiments were performed on a Thin Film NF DK membrane, thermostated at 50°C and at a pressure of 3.5 MPa with four different samples (from four Hungarian cities - Eger, Mezőkövesd, Bogács, Miskolc-Tapolca) using batch plant. Reproducibility of experiments was also investigated using water samples from Komárom at 50 and 60°C. The results showed that NF DK could achieve high retention of divalent ions. The results of the second phase of the experiments proved that water flux and rejections were very stable. After filtration, the scaling properties of thermal water were simulated with the help of chemical equilibrium modelling software, called Visual MINTEQ 3.0. The results of the permeate samples prove that nanofiltration is a successful process in preventing scaling of thermal water for further use.

  16. Inter-Annual Variability in Stream Water Temperature, Microclimate and Heat Exchanges: a Comparison of Forest and Moorland Environments

    NASA Astrophysics Data System (ADS)

    Garner, G.; Hannah, D. M.; Malcolm, I.; Sadler, J. P.

    2012-12-01

    Riparian forest is recognised as important for moderating stream temperature variability and has the potential to mitigate thermal extremes in a changing climate. Previous research on the heat exchanges controlling water column temperature has often been short-term or seasonally-constrained, with the few multi-year studies limited to a maximum of two years. This study advances previous work by providing a longer-term perspective which allows assessment of inter-annual variability in stream temperature, microclimate and heat exchange dynamics between a semi-natural woodland and a moorland (no trees) reach of the Girnock Burn, a tributary of the Scottish Dee. Automatic weather stations collected 15-minute data over seven consecutive years, which to our knowledge is a unique data set in providing the longest term perspective to date on stream temperature, microclimate and heat exchange processes. Results for spring-summer indicate that the presence of a riparian canopy has a consistent effect between years in reducing the magnitude and variability of mean daily water column temperature and daily net energy totals. Differences in the magnitude and variability in net energy fluxes between the study reaches were driven primarily by fluctuations in net radiation and latent heat fluxes in response to between- and within-year variability in growth of the riparian forest canopy at the forest and prevailing weather conditions at both the forest and moorland. This research provides new insights on the inter-annual variability of stream energy exchanges for moorland and forested reaches under a wide range of climatological and hydrological conditions. The findings therefore provide a more robust process basis for modelling the impact of changes in forest practice and climate change on river thermal dynamics.

  17. Annual cycles of deep-ocean biogeochemical export fluxes in subtropical and subantarctic waters, southwest Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Nodder, Scott D.; Chiswell, Stephen M.; Northcote, Lisa C.

    2016-04-01

    The annual cycles of particle fluxes derived from moored sediment trap data collected during 2000-2012 in subtropical (STW) and subantarctic waters (SAW) east of New Zealand are presented. These observations are the most comprehensive export flux time series from temperate Southern Hemisphere latitudes to date. With high levels of variability, fluxes in SAW were markedly lower than in STW, reflecting the picophytoplankton-dominated communities in the iron-limited, high nutrient-low chlorophyll SAW. Austral spring chlorophyll blooms in surface STW were near synchronous with elevated fluxes of bio-siliceous, carbonate, and organic carbon-rich materials to the deep ocean, probably facilitated by diatom and/or coccolithophorid sedimentation. Lithogenic fluxes were also high in STW, compared to SAW, reflecting proximity to the New Zealand landmass. In contrast, the highest biogenic fluxes in SAW occurred in spring when surface chlorophyll concentrations were low, while highest annual chlorophyll concentrations were in summer with no associated flux increase. We hypothesize that the high spring export in SAW results from subsurface chlorophyll accumulation that is not evident from remote-sensing satellites. This material was also rich in biogenic silica, perhaps related to the preferential export of diatoms and other silica-producing organisms, such as silicoflagellates and radiolarians. Organic carbon fluxes in STW are similar to that of other mesotrophic to oligotrophic waters (˜6-7 mg C m-2 d-1), whereas export from SAW is below the global average (˜3 mg C m-2 d-1). Regional differences in flux across the SW Pacific and Tasman region reflect variations in physical processes and ecosystem structure and function.

  18. Mean annual streamflow of selected drainage basins in the coal area of southeastern Montana. Water-resources investigations (final)

    SciTech Connect

    Ferreira, R.F.

    1981-10-01

    Streamflow characteristics of drainage basins within the Fort Union coal region of southeastern Montana were estimated to provide premining data for evaluating the future effects of mining on the environment. Estimated annual mean streamflow at 22 data-collection stations for water years 1975-77 ranged from 0 to 887 cubic feet per second. These estimates are based on miscellaneous-streamflow records at each station and continuous-streamflow records from other stations in the study area. Estimated mean annual streamflow for a 10-year period (water years 1968-77) ranged from 0 to 572 cubic feet per second. Many of the drainage basins had a mean annual runoff of less than 0.60 inch; the maximum observed mean annual runoff was 4.45 inches.

  19. Plastic Response of Tracheids in Pinus pinaster in a Water-Limited Environment: Adjusting Lumen Size instead of Wall Thickness

    PubMed Central

    Carvalho, Ana; Nabais, Cristina; Vieira, Joana; Rossi, Sergio; Campelo, Filipe

    2015-01-01

    The formation of wood results from cambial activity and its anatomical properties reflect the variability of environmental conditions during the growing season. Recently, it was found that wood density variations in conifers growing under cold-limited environment result from the adjustment of cell wall thickness (CWT) to temperature. Additionally, it is known that intra-annual density fluctuations (IADFs) are formed in response to precipitation after the summer drought. Although IADFs are frequent in Mediterranean conifers no study has yet been conducted to determine if these structures result from the adjustment of lumen diameter (LD) or CWT to soil water availability. Our main objective is to investigate the intra-ring variation of wood anatomical features (LD and CWT) in Pinus pinaster Ait. growing under a water-limited environment. We compared the tracheidograms of LD and CWT for the years 2010–2013 in P. pinaster growing in the west coast of Portugal. Our results suggest a close association between LD and soil moisture content along the growing season, reinforcing the role of water availability in determining tracheid size. Compared with CWT, LD showed a higher intra- and inter-annual variability suggesting its strong adjustment value to variations in water availability. The formation of a latewood IADF appears to be predisposed by higher rates of cell production in spring and triggered by early autumn precipitation. Our findings reinforce the crucial role of water availability on cambial activity and wood formation in Mediterranean conifers, and emphasize the high plasticity of wood anatomical features under Mediterranean climate. PMID:26305893

  20. Plastic Response of Tracheids in Pinus pinaster in a Water-Limited Environment: Adjusting Lumen Size instead of Wall Thickness.

    PubMed

    Carvalho, Ana; Nabais, Cristina; Vieira, Joana; Rossi, Sergio; Campelo, Filipe

    2015-01-01

    The formation of wood results from cambial activity and its anatomical properties reflect the variability of environmental conditions during the growing season. Recently, it was found that wood density variations in conifers growing under cold-limited environment result from the adjustment of cell wall thickness (CWT) to temperature. Additionally, it is known that intra-annual density fluctuations (IADFs) are formed in response to precipitation after the summer drought. Although IADFs are frequent in Mediterranean conifers no study has yet been conducted to determine if these structures result from the adjustment of lumen diameter (LD) or CWT to soil water availability. Our main objective is to investigate the intra-ring variation of wood anatomical features (LD and CWT) in Pinus pinaster Ait. growing under a water-limited environment. We compared the tracheidograms of LD and CWT for the years 2010-2013 in P. pinaster growing in the west coast of Portugal. Our results suggest a close association between LD and soil moisture content along the growing season, reinforcing the role of water availability in determining tracheid size. Compared with CWT, LD showed a higher intra- and inter-annual variability suggesting its strong adjustment value to variations in water availability. The formation of a latewood IADF appears to be predisposed by higher rates of cell production in spring and triggered by early autumn precipitation. Our findings reinforce the crucial role of water availability on cambial activity and wood formation in Mediterranean conifers, and emphasize the high plasticity of wood anatomical features under Mediterranean climate.

  1. The Role of Vegetation Dynamics on the Soil Water Balance in Water-Limited Ecosystems

    NASA Astrophysics Data System (ADS)

    Montaldo, N.; Rondena, R.; Albertson, J. D.; Mancini, M.

    2003-12-01

    The structure and function of the vegetation regulates the exchange of mass, energy and momentum across the biosphere-atmosphere interface. Vegetation dynamics are usually neglected, other than seasonal phenology, in land surface models (LSMs). However, changes in vegetation densities, influencing the partitioning of incoming solar energy into sensible and latent heat fluxes, can result in long-term changes in both local and global climates (e.g., precipitation and temperature), which in turn will feedback to affect the vegetation growth. In semi-arid regions, this may result in persistent drought and desertification, with substantial impacts on the human populations of these regions through reduction in agricultural productivity and reduction in quantity and quality of water supply. With an objective of finding a simple vegetation model able to accurately simulate the leaf area index (LAI) dynamics, vegetation models of different level of complexity (e.g., including or not the modeling of the root biomass or the modeling of the dead biomass) are developed and compared. The vegetation dynamics models are coupled to a LSM, with the vegetation models providing the green biomass and the LAI evolution through time, and the LSM using this information in the computation of the land surface fluxes and updating the soil water content in the root-zone. We explore the models on a case study of a water limited grass field in California. Results show that a simple vegetation model that simulates the living aboveground green biomass (i.e., with low parameterization and computational efforts) is able to accurately simulate the LAI. Results also highlight the importance of including the plant growth model in the LSM when studying the climate-soil-vegetation interactions and the impact of watershed management practices on the scarce water resources over moderate to long time scales. The inclusion of the vegetation model in the LSM is demonstrated to be essential for assessing the

  2. Water resources data for Alabama, water year 1992. Water-data report (Annual), 1 October 1991-30 September 1992

    SciTech Connect

    Pearman, J.L.; Sedberry, F.C.; Stricklin, V.E.; Cole, P.W.

    1993-03-01

    Water resources data for the 1992 water year for Alabama consist of records of stage, discharge, and water quality of streams; stage and contents of lakes and reservoirs; and water levels in wells. The report includes records on both surface and ground water in the State. Specifically, it contains: (1) discharge records for 100 streamflow-gaging stations, for 63 partial-record or miscellaneous streamflow stations; (2) stage and content records for 13 lakes and reservoirs and stage at 34 stations; (3) water-quality records for 26 streamflow-gaging stations, 7 lake stations, for 32 ungaged streamsites, and for 1 precipitation station; (4) water temperature and specific conductance at 23 surface-water stations; (5) dissolved oxygen at 8 stations; (6) sediment data at 18 stations; and (7) water-level records for 3 recording observation wells and 59 periodic observation wells. Discharge records for a few pertinent stations in bordering States are also included in the report.

  3. Annual yield and selected hydrologic data for the Arkansas River Basin compact, Arkansas-Oklahoma, 1985 water year

    USGS Publications Warehouse

    Moore, M.A.; Lamb, T.E.

    1986-01-01

    The computed annual yield and deficiency of the subbasins as defined in the Arkansas River Compact, Arkansas-Oklahoma, are given in tables. Actual runoff from the subbasins and depletion caused by major reservoirs in the compact area are also given in tabular form. Monthly, maximum, minimum, and mean discharges are shown for the 14 streamflow stations used in computing annual yield. Water-quality data are shown for four sites in the compact area. (USGS)

  4. Water resources data for Indiana, water year 1995. Water-data report (Annual), 1 October 1994-30 September 1995

    SciTech Connect

    Stewart, J.A.; Keeton, C.R.; Benedict, B.L.; Hammil, L.E.

    1996-06-01

    Water resources data for the 1995 water year for Indiana consists of records of discharge, stage, and water quality of streams and wells; reservoir stage and contents; and waterlevels in lakes and wells. The report contains records of discharge for 166 stream-gaging stations, stage for 6 stream stations, stage and contents for 1 reservoir, water quality for 1 stream, and water levels for 80 lakes and 94 observation wells. These data represent that part of the National Water Data System operated by the U.S. Geological Survey in Indiana in cooperation with State and Federal agencies.

  5. Limiter

    DOEpatents

    Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

    1984-10-19

    A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

  6. Relating biomass and vegetation structure in water limited ecosystems using a celluar automata based model

    NASA Astrophysics Data System (ADS)

    Frechen, Nanu; Hinz, Christoph; McGrath, Gavan

    2015-04-01

    Within arid and semiarid regions banded vegetation patterns are wide spread. While the soil-vegetation feedback causing this self-organized has been well understood and implemented in various models, the relationship between the actual pattern, e.g. band width and spacing as well as plant density, has not been well understood. In this study we use a cellular automaton [1] to investigate the effect of infiltration properties and rainfall on patter formation as well as on biomass production and vegetation coverage. The first part of the investigation showed that the model is consistent with the existing knowledge on the dependence of wavelength on annual rainfall. We use the same parameter space to assess biomass and fractional coverage. We found that there is a nonlinear relationship between biomass and infiltration capacity normalized with rainfall input. This indicates that the degree of organisation is not directly related to the productivity as expressed with biomass. Similar results were found for fractional surface cover of the vegetation. [1] McGrath, G. S., K. Paik, and C. Hinz. 2012. Microtopography alters self-organized vegetation patterns in water-limited ecosystems, Journal of Geophysical Research: Biogeosciences (2005-2012) 117, G03021, doi:10.1029/2011JG001870

  7. Water resources data for Alabama, water year 1994. Water-data report (Annual), 1 October 1993-30 September 1994

    SciTech Connect

    Pearman, J.L.; Stricklin, V.E.; Cole, P.W.

    1995-03-01

    Water resources data for the 1994 water year for Alabama consist of records of stage, discharge, and water quality of streams; stages and contents of lakes and reservoirs; and water levels in wells. This report includes records on both surface and ground water in the State. Specifically, it contains: (1) discharge records for 104 streamflow-gaging stations, for 77 partial-record or miscellaneous streamflow stations; (2) stage and content records for 13 lakes and reservoirs and stage or elevation at 33 stations; (3) water-quality records for 23 streamflow-gaging stations, 3 lake stations, for 70 ungaged streamsites, and for 1 precipitation station; (4) water temperature and specific conductance at 17 surface-water stations; (5) dissolved oxygen at 7 stations; (6) sediment data at 43 stations; and (7) water-level records at 4 recording observation wells and 56 periodic observation wells. Also included are lists of active and discontinued continuous-record surface-water discharge stations, continuous-record surface-water stage stations, continuous-record surface-water-quality stations, and partial-record and miscellaneous surface-water-quality stations.

  8. The radiative role of ozone and water vapour in the annual temperature cycle in the tropical tropopause layer

    NASA Astrophysics Data System (ADS)

    Ming, Alison; Maycock, Amanda C.; Hitchcock, Peter; Haynes, Peter

    2017-05-01

    The structure and amplitude of the radiative contributions of the annual cycles in ozone and water vapour to the prominent annual cycle in temperatures in the tropical tropopause layer (TTL) are considered. This is done initially through a seasonally evolving fixed dynamical heating (SEFDH) calculation. The annual cycle in ozone is found to drive significant temperature changes predominantly locally (in the vertical) and roughly in phase with the observed TTL annual cycle. In contrast, temperature changes driven by the annual cycle in water vapour are out of phase with the latter. The effects are weaker than those of ozone but still quantitatively significant, particularly near the cold point (100 to 90 hPa) where there are substantial non-local effects from variations in water vapour in lower layers of the TTL. The combined radiative heating effect of the annual cycles in ozone and water vapour maximizes above the cold point and is one factor contributing to the vertical structure of the amplitude of the annual cycle in lower-stratospheric temperatures, which has a relatively localized maximum around 70 hPa. Other important factors are identified here: radiative damping timescales, which are shown to maximize over a deep layer centred on the cold point; the vertical structure of the dynamical heating; and non-radiative processes in the upper troposphere that are inferred to impose a strong constraint on tropical temperature perturbations below 130 hPa. The latitudinal structure of the radiative contributions to the annual cycle in temperatures is found to be substantially modified when the SEFDH assumption is relaxed and the dynamical response, as represented by a zonally symmetric calculation, is taken into account. The effect of the dynamical response is to reduce the strong latitudinal gradients and inter-hemispheric asymmetry seen in the purely radiative SEFDH temperature

  9. Annual Storm Water Report for the Y-12 National Security Complex Oak Ridge, Tennessee

    SciTech Connect

    2013-12-01

    This is the second annual storm water report prepared in accordance with the National Pollutant Discharge Elimination System (NPDES) permit issued to the Y-12 National Security Complex (Y-12 Complex) on December 1, 2011, and the corresponding Y-12 Storm Water Pollution Prevention Plan (SWP3) which became effective on September 7, 2012. However, Appendix A does contain some analytical data gathered under the previous NPDES permit and SWP3 for comparison purposes. The quality of storm water exiting the Y-12 Complex via East Fork Poplar Creek remained relatively stable from 2012 to 2013. However, there was one largely unexpected high concentration of mercury noted in an area that is not known to have previously been a mercury use area. This was noted in Sector AA, Outfall 014. This outfall is normally sampled on a rotating basis but, due this elevated concentration, will be sampled again in 2014. The Y-12 Complex will continue to implement appropriate BMPs and reduce outside material storage ares where possible. Emphasis will continue to be placed on site inspections and timely implementation of proper storm water control measures.

  10. Water resources data for Michigan, water year 1995. Water-data report (Annual), 1 October 1994-30 September 1995

    SciTech Connect

    Blumer, S.P.; Behrendt, T.E.; Ellis, J.M.; Minnerick, R.J.; LeuVoy, R.L.

    1996-05-01

    Water resources data for the 1995 water year for Michigan consists of records of stage, discharge, and water quality of streams; stage and contents of lakes and reservoirs; and ground water levels. This report contains discharge records for 148 streamflow-gaging stations; stage only records for 2 stream-gaging stations and 19 lake-gaging stations; stage and contents for 4 lakes and reservoirs; water-quality records for 16 streamflow-gaging stations and 1 lake-gaging station; water-level records for 42 ground-water wells. Also included are 29 crest-stage partial-record stations and 2 low-flow partial-record stations. Additional water data were collected at various sites not involved in the systematic data-collection-program. Miscellaneous data were collected at 74 measuring sites.

  11. Optimizing the use of limited water in agricultural systems

    USDA-ARS?s Scientific Manuscript database

    About 92% of freshwater withdrawals in Uzbekistan are used for irrigation, whereas in the United States, freshwater withdrawls account for about 33% of the total use. In Uzbekistan, most of the water suitable for irrigation has already been allocated. In the United States, groundwater depletion and ...

  12. Water resources data for Indiana, water year 1996. Water-data report (Annual), 1 October 1995-30 September 1996

    SciTech Connect

    Stewart, J.A.; Keeton, C.R.; Benedict, B.L.; Hammil, L.E.

    1997-05-01

    This report contains records of discharge for 166 stream-gaging stations, stage for 6 stream stations, stage and contents for 1 reservoir, water quality for 2 streams, and water levels for 80 lakes and 94 observation wells. Also included are records of 39 water-quality sites, not part of the systematic data-collection program, and are shown as miscellaneous samplings.

  13. Water resources data for Minnesota, water year 1996. Water-data report (Annual), 1 October 1995-30 September 1996

    SciTech Connect

    Mitton, G.B.; Wakeman, E.S.; Guttormson, K.G.

    1997-04-03

    This report contains discharge records for 100 stream-gaging stations; stage and contents for 14 lakes and reservoirs; water quality for 34 stream-gaging stations; and water levels for 15 observation wells. Also included are 87 high-flow partial-record stations, and rainfall totals and water quality for one precipitation station.

  14. N-limited or N and P co-limited indications in the surface waters of three Mediterranean basins

    NASA Astrophysics Data System (ADS)

    Tanaka, T.; Thingstad, T. F.; Christaki, U.; Colombet, J.; Cornet-Barthaux, V.; Courties, C.; Grattepanche, J.-D.; Lagaria, A.; Nedoma, J.; Oriol, L.; Psarra, S.; Pujo-Pay, M.; van Wambeke, F.

    2010-11-01

    The limiting nutrient for the pelagic microbial food web in the Mediterranean Sea was investigated in the nutrient manipulated microcosms during summer 2008. Surface waters were collected into 12 carboys at a center of anticyclonic eddy at the Western Basin, the Ionian Basin, and the Levantine Basin, respectively. As compared to the Redfield ratio, the ratio of N to P in the collected waters was always smaller in the dissolved inorganic fraction but higher in both dissolved and particulate organic fractions. Four different treatments in triplicates (addition of ammonium, phosphate, a combination of both, and the unamended control) were set up for the carboys. Responses of chemical and biological parameters in these different treatments were measured during the incubation (3-4 days). Temporal changes of turnover time of phosphate and ATP, and alkaline phosphatase activity during the incubation suggested that the phytoplankton and heterotrophic prokaryotes (Hprok) communities were not purely P-limited at any studied stations. Statistical comparison between the treatments for a given parameter measured at the end of the incubation did not find pure P-limitation in any chemical and biological parameters at three study sites. Primary production was consistently limited by N, and Hprok growth was not limited by N nor P in the Western Basin, but N-limited in the Ionian Basin, and N and P co-limited in the Levantine Basin. Our results demonstrated the gap between biogeochemical features and biological responses in terms of the limiting nutrient. We question the general notion that Mediterranean surface waters are limited by P alone during the stratified period.

  15. Strong seepage of shallow groundwater shifts the timing of the annual thermal signals in stream water

    NASA Astrophysics Data System (ADS)

    Briggs, M. A.; Johnson, Z. C.; Snyder, C.; Hitt, N. P.; White, E. A.; Lane, J. W., Jr.; Nelms, D. L.

    2016-12-01

    Conventional wisdom indicates that while short-term (e.g. diurnal) thermal variance in streams may be attenuated by groundwater seepage, annual temperature swings will essentially track the local air temperature signal. However, the temperature of shallow (less than 5 m depth) groundwater from seepage zones may not be constant and near the local mean air temperature, but instead will fluctuate seasonally, and show a pronounced phase lag from the annual air signal. The degree of phase lag will be dependent on the rate of vertical fluid and heat exchange through shallow aquifer sediments. Gaining headwater streams might be expected to adopt similar phase lags to local seepage zones. We explore these dynamics through 9 mountain watersheds in Shenandoah National Park, VA, USA that harbor critical habitat for cold-water brook trout (Salvelinus fontinalis). Daily paired air and stream water temperature records were collected for up to 5 years at several stream locations along each watershed. Sinusoids fit to multiple-year data from more than 100 total locations indicate an average phase shift from air to surface water of approximately 10 d; this may primarily be due to strong conductive exchange with the rocky alluvial aquifer in generally incised and shaded channels. A subset of these transects (n=4) showed phase-lags greater than 20 d, coinciding with locations of particularly pronounced diurnal variance attenuation, indicating strong groundwater influence. Shallow bedrock, evaluated throughout the watersheds with passive seismic methods, restricts downward infiltration of precipitation in the mountain bedrock aquifers. Numerical 1D vertical aquifer models indicate similar phase lags in shallow groundwater at the bedrock contact to that observed in stream seepage zones. Therefore, contrary to conventional wisdom, shaded mountain streams with strong groundwater influence may adopt the annual thermal signature of the adjacent aquifer, shifting the stream thermal maxima

  16. Annual water quality data report for the Waste Isolation Pilot Plant

    SciTech Connect

    Lyon, M.L. )

    1989-04-01

    This is the fourth Annual Water Quality Data Report for the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico. The WIPP project is operated by the United States Department of Energy (DOE) for the purpose of providing a research and development facility to demonstrate the safe disposal of transuranic radioactive wastes generated by the defense activities of the United States Government. This report presents water quality data collected from January 1988 through December 1988 from 16 designated pre-operational (WIPP facility) monitoring wells, two additional wells, and 10 privately-owned wells in the vicinity of the WIPP. Additionally, water samples were collected from the Air Intake Shaft during shaft construction activities at the WIPP. This report lists pertinent information regarding the monitoring wells sampled, sampling zone, dates pumped, and types of samples collected during 1988. Comparative data from previous samplings of all wells can be found in Uhland and Randall (1986), Uhland et al. (1987), Randall et al. (1988), as well as in this report. The data reported by the Water Quality Sampling Program in this and previous reports indicate that serial sampling is a very useful tool in determining sample representativeness from wells in the WIPP vicinity. Serial sample field chemistry data are demonstrated to be highly accurate and precise as indicated by the excellent overall average percent spike recovery values and low RPD values reported for the sampling events. Serial sample field chemistry data and laboratory water quality parameter analyses gathered by the WQSP since January 1985 are the foundation for a pre-operational water quality baseline at the WIPP. 32 refs., 66 figs., 96 tabs.

  17. 25 CFR 171.710 - Can I receive irrigation water if I am granted an Annual Assessment Waiver?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Can I receive irrigation water if I am granted an Annual Assessment Waiver? 171.710 Section 171.710 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER IRRIGATION OPERATION AND MAINTENANCE Non-Assessment Status § 171.710 Can I receive irrigation water if I am granted an...

  18. Fresh Water Generation from Aquifer-Pressured Carbon Storage: Annual Report FY09

    SciTech Connect

    Wolery, T; Aines, R; Hao, Y; Bourcier, W; Wolfe, T; Haussman, C

    2009-11-25

    This project is establishing the potential for using brine pressurized by Carbon Capture and Storage (CCS) operations in saline formations as the feedstock for desalination and water treatment technologies including reverse osmosis (RO) and nanofiltration (NF). The aquifer pressure resulting from the energy required to inject the carbon dioxide provides all or part of the inlet pressure for the desalination system. Residual brine is reinjected into the formation at net volume reduction, such that the volume of fresh water extracted balances the volume of CO{sub 2} injected into the formation. This process provides additional CO{sub 2} storage capacity in the aquifer, reduces operational risks (cap-rock fracturing, contamination of neighboring fresh water aquifers, and seismicity) by relieving overpressure in the formation, and provides a source of low-cost fresh water to offset costs or operational water needs. This multi-faceted project combines elements of geochemistry, reservoir engineering, and water treatment engineering. The range of saline formation waters is being identified and analyzed. Computer modeling and laboratory-scale experimentation are being used to examine mineral scaling and osmotic pressure limitations. Computer modeling is being used to evaluate processes in the storage aquifer, including the evolution of the pressure field. Water treatment costs are being evaluated by comparing the necessary process facilities to those in common use for seawater RO. There are presently limited brine composition data available for actual CCS sites by the site operators including in the U.S. the seven regional Carbon Sequestration Partnerships (CSPs). To work around this, we are building a 'catalog' of compositions representative of 'produced' waters (waters produced in the course of seeking or producing oil and gas), to which we are adding data from actual CCS sites as they become available. Produced waters comprise the most common examples of saline

  19. Impact of water table level on annual carbon and greenhouse gas balances of a restored peat extraction area

    NASA Astrophysics Data System (ADS)

    Järveoja, Järvi; Peichl, Matthias; Maddison, Martin; Soosaar, Kaido; Vellak, Kai; Karofeld, Edgar; Teemusk, Alar; Mander, Ülo

    2016-05-01

    Peatland restoration may provide a potential after-use option to mitigate the negative climate impact of abandoned peat extraction areas; currently, however, knowledge about restoration effects on the annual balances of carbon (C) and greenhouse gas (GHG) exchanges is still limited. The aim of this study was to investigate the impact of contrasting mean water table levels (WTLs) on the annual C and GHG balances of restoration treatments with high (ResH) and low (ResL) WTL relative to an unrestored bare peat (BP) site. Measurements of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes were conducted over a full year using the closed chamber method and complemented by measurements of abiotic controls and vegetation cover. Three years following restoration, the difference in the mean WTL resulted in higher bryophyte and lower vascular plant cover in ResH relative to ResL. Consequently, greater gross primary production and autotrophic respiration associated with greater vascular plant cover were observed in ResL compared to ResH. However, the means of the measured net ecosystem CO2 exchanges (NEE) were not significantly different between ResH and ResL. Similarly, no significant differences were observed in the respective means of CH4 and N2O exchanges. In comparison to the two restored sites, greater net CO2, similar CH4 and greater N2O emissions occurred in BP. On the annual scale, ResH, ResL and BP were C sources of 111, 103 and 268 g C m-2 yr-1 and had positive GHG balances of 4.1, 3.8 and 10.2 t CO2 eq ha-1 yr-1, respectively. Thus, the different WTLs had a limited impact on the C and GHG balances in the two restored treatments 3 years following restoration. However, the C and GHG balances in ResH and ResL were considerably lower than in BP due to the large reduction in CO2 emissions. This study therefore suggests that restoration may serve as an effective method to mitigate the negative climate impacts of abandoned peat extraction areas.

  20. Derivation and implementation of an annual limit on intake and a derived air concentration value for uranium mill tailings

    SciTech Connect

    Reif, R.H.; Andrews, D.W.

    1995-06-01

    Monitoring workers and work areas at the Department of Energy Uranium Mill Tailings Remedial Action Project sites is complex because all radionuclides in the {sup 238}U and {sup 235}U decay chains may be present in an airborne uranium mill tillings matrix. Previous monitoring practices involved isotopic analysis of the air filter to determine the activity of each radionuclide of concern and comparing the results to the specified derived air concentration. The annual limit on intake and derived air concentration values have been derived here for the uranium mill tailings matrix to simplify the procedure for evaluation of air monitoring results and assessment of the need for individual monitoring. Implementation of the derived air concentration for uranium mill tailings involves analyzing air samples for long-lived gross alpha activity and comparing the activity concentration to the derived air concentration. Health physics decisions regarding assessment of airborne concentrations is more cost-effective because isotopic analysis of air samples is not necessary. 12 refs., 2 tabs.

  1. Water deficit on the accumulation of biomass and artemisinin in annual wormwood (Artemisia annua L., Asteraceae)

    USDA-ARS?s Scientific Manuscript database

    Despite the importance of Artemisia annua as the only source of the anti-parasitic drug artemisinin, little can be found on the role of biotic and abiotic stress on artemisinin. Water stress is the most limiting factor on plant growth, but can trigger secondary metabolite accumulation, depending on...

  2. A method to derive the relationship between the annual and short-term air quality limits--analysis using the WHO Air Quality Guidelines for health protection.

    PubMed

    Lai, Hak-Kan; Hedley, Anthony J; Thach, Thuan-Quoc; Wong, Chit-Ming

    2013-09-01

    The World Health Organization (WHO) Air Quality Guidelines (AQG) were launched in 2006, but gaps remain in evidence on health impacts and relationships between short-term and annual AQG needed for health protection. We tested whether relationships between WHO short-term and annual AQG for particulates (PM10 and PM2.5) and nitrogen dioxide (NO2) are concordant worldwide and derived the annual limits for sulfur dioxide (SO2) and ozone (O3) based on the short-term AQG. We obtained air pollutant data over seven years (2004-2010) in seven cities from Asia-Pacific, North America and Europe. Based on probability distribution concept using maximum as the short-term limit and arithmetic mean as the annual limit, we developed a new method to derive limit value one from another in each paired limits for each pollutant with capability to account for allowable exceedances. We averaged the limit derived each year for each city, then used meta-analysis to pool the limit values in all cities. Pooled mean short-term limit for NO2 (140.5μg/m(3) [130.6-150.4]) was significantly lower than the WHO AQG of 200μg/m(3) while for PM10 (46.4μg/m(3) [95CI:42.1-50.7]) and PM2.5 (28.6μg/m(3) [24.5-32.6]) were not significantly different from the WHO AQG of 50 and 25μg/m(3) respectively. Pooled mean annual limits for SO2 and O3 were 4.6μg/m(3) [3.7-5.5] and 27.0μg/m(3) [21.7-32.2] respectively. Results were robust in various sensitivity analyses. The distribution relationships between the current WHO short-term and annual AQG are supported by empirical data from seven cities for PM10 and PM2.5, but not for NO2. The short-term AQG for NO2 should be lowered for concordance with the selected annual AQG for health protection. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. Limiter

    DOEpatents

    Cohen, Samuel A.; Hosea, Joel C.; Timberlake, John R.

    1986-01-01

    A limiter with a specially contoured front face accommodates the various power scrape-off distances .lambda..sub.p, which depend on the parallel velocity, V.sub..parallel., of the impacting particles. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution.

  4. Ecological optimality in water-limited natural soil-vegetation systems. II - Tests and applications

    NASA Technical Reports Server (NTRS)

    Eagleson, P. S.; Tellers, T. E.

    1982-01-01

    The long-term optimal climatic climax soil-vegetation system is defined for several climates according to previous hypotheses in terms of two free parameters, effective porosity and plant water use coefficient. The free parameters are chosen by matching the predicted and observed average annual water yield. The resulting climax soil and vegetation properties are tested by comparison with independent observations of canopy density and average annual surface runoff. The climax properties are shown also to satisfy a previous hypothesis for short-term optimization of canopy density and water use coefficient. Using these hypotheses, a relationship between average evapotranspiration and optimum vegetation canopy density is derived and is compared with additional field observations. An algorithm is suggested by which the climax soil and vegetation properties can be calculated given only the climate parameters and the soil effective porosity. Sensitivity of the climax properties to the effective porosity is explored.

  5. Ecological optimality in water-limited natural soil-vegetation systems. II - Tests and applications

    NASA Technical Reports Server (NTRS)

    Eagleson, P. S.; Tellers, T. E.

    1982-01-01

    The long-term optimal climatic climax soil-vegetation system is defined for several climates according to previous hypotheses in terms of two free parameters, effective porosity and plant water use coefficient. The free parameters are chosen by matching the predicted and observed average annual water yield. The resulting climax soil and vegetation properties are tested by comparison with independent observations of canopy density and average annual surface runoff. The climax properties are shown also to satisfy a previous hypothesis for short-term optimization of canopy density and water use coefficient. Using these hypotheses, a relationship between average evapotranspiration and optimum vegetation canopy density is derived and is compared with additional field observations. An algorithm is suggested by which the climax soil and vegetation properties can be calculated given only the climate parameters and the soil effective porosity. Sensitivity of the climax properties to the effective porosity is explored.

  6. Exploring the limits of the terrestrial fresh water cycle

    NASA Astrophysics Data System (ADS)

    van der Ent, Ruud; Wang-Erlandsson, Lan; Keys, Patrick; Savenije, Hubert

    2014-05-01

    Precipitation is the ultimate source of life on this planet: it makes our crops grow, provides drinking water, feeds rivers and replenishes groundwater aquifers. Climate modelling studies estimate changes in precipitation due to increased greenhouse gas emissions and climate impact studies use those estimates as input to their (hydrological) models to predict future water availability and societal impact. However, humans also significantly alter the land surface by, for example, deforestation and irrigation, which is not frequently taken into account in our climate studies. Here, we present an overview of several papers in the field of moisture recycling, published by our group, that show the extent to which terrestrial evaporation influences terrestrial precipitation. It is found that 38% of the terrestrial precipitation originates from terrestrial evaporation and that 58% of all terrestrial evaporation recycles, and return again as terrestrial precipitation. Knowing this, it is clear that evaporation is not necessary a loss to the hydrological cycle. We show that in some cases even transpiration during the dry season can act as a moisture source for a distant region. To assess the vulnerability of a region to local and remote land use changes we propose the concept of the precipitationshed, which maps out a region's precipitation sources. Our results are useful in mapping out possible land use change threats, but also opportunities to safeguard our water resources in the Anthropocene.

  7. Common garden test of range limits as predicted by a species distribution model in the annual plant Mimulus bicolor.

    PubMed

    Dixon, Andrea L; Busch, Jeremiah W

    2017-06-01

    Direct tests of a species distribution model (SDM) were used to evaluate the hypothesis that the northern and southern edges of Mimulus bicolor's geographical range are limited by temperature and precipitation. Climatic suitability was predicted using an SDM informed only by temperature and precipitation variables. These predictions were tested by growing plants in growth chambers with temperature and watering treatments informed by weather stations characteristic of environments at the geographic center, edges, and outside the range. An Aster analysis was used to assess whether treatments significantly affected lifetime flower production and to test for local adaptation. The relationship between climatic suitability and lifetime flower number in the growth chambers was also evaluated. The temperature and watering treatments significantly affected lifetime flower number, although local adaptation was not detected. Flower production was significantly lower under the two edge treatments compared to the central treatment. While no flowers were produced under the beyond-south treatments, flower production was greatest under the beyond-north treatment. These results suggest a hard abiotic limit at the southern edge, and suitable temperature and precipitation conditions beyond the northern edge. While predicted climatic suitability was significantly lower at the range edges, there was no correlation between the climatic suitability of the weather stations' locations and flower production. These results suggest that temperature and precipitation play a significant role in defining the distribution of M. bicolor, but also indicate that dispersal limitation or metapopulation dynamics are likely important factors restricting access to habitable sites beyond the northern range limit. © 2017 Botanical Society of America.

  8. BOREAS RSS-8 BIOME-BGC SSA Simulation of Annual Water and Carbon Fluxes

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Kimball, John

    2000-01-01

    The BOREAS RSS-8 team performed research to evaluate the effect of seasonal weather and landcover heterogeneity on boreal forest regional water and carbon fluxes using a process-level ecosystem model, BIOME-BGC, coupled with remote sensing-derived parameter maps of key state variables. This data set contains derived maps of landcover type and crown and stem biomass as model inputs to determine annual evapotranspiration, gross primary production, autotrophic respiration, and net primary productivity within the BOREAS SSA-MSA, at a 30-m spatial resolution. Model runs were conducted over a 3-year period from 1994-1996; images are provided for each of those years. The data are stored in binary image format. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  9. Control factors and scale analysis of annual river water, sediments and carbon transport in China

    PubMed Central

    Song, Chunlin; Wang, Genxu; Sun, Xiangyang; Chang, Ruiying; Mao, Tianxu

    2016-01-01

    Under the context of dramatic human disturbances on river system, the processes that control the transport of water, sediment, and carbon from river basins to coastal seas are not completely understood. Here we performed a quantitative synthesis for 121 sites across China to find control factors of annual river exports (Rc: runoff coefficient; TSSC: total suspended sediment concentration; TSSL: total suspended sediment loads; TOCL: total organic carbon loads) at different spatial scales. The results indicated that human activities such as dam construction and vegetation restoration might have a greater influence than climate on the transport of river sediment and carbon, although climate was a major driver of Rc. Multiple spatial scale analyses indicated that Rc increased from the small to medium scale by 20% and then decreased at the sizable scale by 20%. TSSC decreased from the small to sizeable scale but increase from the sizeable to large scales; however, TSSL significantly decreased from small (768 g·m−2·a−1) to medium spatial scale basins (258 g·m−2·a−1), and TOCL decreased from the medium to large scale. Our results will improve the understanding of water, sediment and carbon transport processes and contribute better water and land resources management strategies from different spatial scales. PMID:27166177

  10. Control factors and scale analysis of annual river water, sediments and carbon transport in China.

    PubMed

    Song, Chunlin; Wang, Genxu; Sun, Xiangyang; Chang, Ruiying; Mao, Tianxu

    2016-05-11

    Under the context of dramatic human disturbances on river system, the processes that control the transport of water, sediment, and carbon from river basins to coastal seas are not completely understood. Here we performed a quantitative synthesis for 121 sites across China to find control factors of annual river exports (Rc: runoff coefficient; TSSC: total suspended sediment concentration; TSSL: total suspended sediment loads; TOCL: total organic carbon loads) at different spatial scales. The results indicated that human activities such as dam construction and vegetation restoration might have a greater influence than climate on the transport of river sediment and carbon, although climate was a major driver of Rc. Multiple spatial scale analyses indicated that Rc increased from the small to medium scale by 20% and then decreased at the sizable scale by 20%. TSSC decreased from the small to sizeable scale but increase from the sizeable to large scales; however, TSSL significantly decreased from small (768 g·m(-2)·a(-1)) to medium spatial scale basins (258 g·m(-2)·a(-1)), and TOCL decreased from the medium to large scale. Our results will improve the understanding of water, sediment and carbon transport processes and contribute better water and land resources management strategies from different spatial scales.

  11. Control factors and scale analysis of annual river water, sediments and carbon transport in China

    NASA Astrophysics Data System (ADS)

    Song, Chunlin; Wang, Genxu; Sun, Xiangyang; Chang, Ruiying; Mao, Tianxu

    2016-05-01

    Under the context of dramatic human disturbances on river system, the processes that control the transport of water, sediment, and carbon from river basins to coastal seas are not completely understood. Here we performed a quantitative synthesis for 121 sites across China to find control factors of annual river exports (Rc: runoff coefficient; TSSC: total suspended sediment concentration; TSSL: total suspended sediment loads; TOCL: total organic carbon loads) at different spatial scales. The results indicated that human activities such as dam construction and vegetation restoration might have a greater influence than climate on the transport of river sediment and carbon, although climate was a major driver of Rc. Multiple spatial scale analyses indicated that Rc increased from the small to medium scale by 20% and then decreased at the sizable scale by 20%. TSSC decreased from the small to sizeable scale but increase from the sizeable to large scales; however, TSSL significantly decreased from small (768 g·m‑2·a‑1) to medium spatial scale basins (258 g·m‑2·a‑1), and TOCL decreased from the medium to large scale. Our results will improve the understanding of water, sediment and carbon transport processes and contribute better water and land resources management strategies from different spatial scales.

  12. Annual and seasonal water storage changes detected from GRACE data in the La Plata Basin

    NASA Astrophysics Data System (ADS)

    Pereira, Ayelen; Pacino, María Cristina

    2012-12-01

    The gravity does not remain constant, but changes over time depending on the redistribution of the masses. Aquatic environments, like a river basin, perform important functions in nature such as control of climate, floods and nutrients; and they also provide goods and services for humanity. To monitor these environments at large spatial scales, the satellite gravity mission GRACE provides time-variable gravity field models that reflect the Earth's gravity field variations due to mass transport processes, like continental water storage variations. The La Plata Basin is the second largest in South America and is a sample of the abundance, variety and quality of natural resources and possibilities offered in connection with the production of goods and services. The objective of this work is to analyze GRACE capability to monitor the water storage variations in the La Plata Basin. Firstly, GRACE solutions from four different processing centers are used to estimate the gravity trend and gravity amplitude over this basin. Afterwards, the calculated hydrological signal is used to obtain mass change models over this hydrographic system's area, using two different methods and for the period from 2002 to 2009. Next, the annual and seasonal water storage changes from GRACE solutions are validated in Argentina by rainfall data over the time periods where extreme weather conditions took place. The results indicate that GRACE detected the variations of the continental water storage in the La Plata Basin, and particularly, it detected the important decrease in the South of the basin. Moreover, a coherency between the estimates of water mass changes and rainfall data was found, which shows that GRACE also detected extreme weather events (such as drought and intense rain episodes) that occurred in the 2004-2009 period in Argentina.

  13. Low-oxygen waters limited habitable space for early animals

    PubMed Central

    Tostevin, R.; Wood, R. A.; Shields, G. A.; Poulton, S. W.; Guilbaud, R.; Bowyer, F.; Penny, A. M.; He, T.; Curtis, A.; Hoffmann, K. H.; Clarkson, M. O.

    2016-01-01

    The oceans at the start of the Neoproterozoic Era (1,000–541 million years ago, Ma) were dominantly anoxic, but may have become progressively oxygenated, coincident with the rise of animal life. However, the control that oxygen exerted on the development of early animal ecosystems remains unclear, as previous research has focussed on the identification of fully anoxic or oxic conditions, rather than intermediate redox levels. Here we report anomalous cerium enrichments preserved in carbonate rocks across bathymetric basin transects from nine localities of the Nama Group, Namibia (∼550–541 Ma). In combination with Fe-based redox proxies, these data suggest that low-oxygen conditions occurred in a narrow zone between well-oxygenated surface waters and fully anoxic deep waters. Although abundant in well-oxygenated environments, early skeletal animals did not occupy oxygen impoverished regions of the shelf, demonstrating that oxygen availability (probably >10 μM) was a key requirement for the development of early animal-based ecosystems. PMID:27659064

  14. Pushing the Limits of an O-18 Water Target

    SciTech Connect

    Nye, J.A.; Dick, D.W.; Nickles, R.J.

    2003-08-26

    A gridded-niobium target was constructed for the improvement of routine [18F]-fluorine production from 18O-enriched water on a CTI RDS 112 cyclotron. Niobium was chosen for its inertness and excellent thermal properties. The target volume consists of a 400{mu}L (active volume) niobium chamber mounted with a single entrance foil supported against an array of 3mm hexagonal holes with 0.25mm aluminum septa, machined by EDM. The target operates at high beam currents and elevated pressures and temperatures with significant reductions in maintenance intervals. Several diagnostic tools such as autoradiography, activation, and neutron logging optimize the performance and yield of the target. Entrance foils including Havar and Nb are used to assess the [18F] chemical compatibility, with FDG synthesis as the test reaction. The gridded, single-foiled niobium target chamber appears to be an improvement compared to a standard double-foiled helium cooled water target used with RDS cyclotrons.

  15. Low-oxygen waters limited habitable space for early animals

    NASA Astrophysics Data System (ADS)

    Tostevin, R.; Wood, R. A.; Shields, G. A.; Poulton, S. W.; Guilbaud, R.; Bowyer, F.; Penny, A. M.; He, T.; Curtis, A.; Hoffmann, K. H.; Clarkson, M. O.

    2016-09-01

    The oceans at the start of the Neoproterozoic Era (1,000-541 million years ago, Ma) were dominantly anoxic, but may have become progressively oxygenated, coincident with the rise of animal life. However, the control that oxygen exerted on the development of early animal ecosystems remains unclear, as previous research has focussed on the identification of fully anoxic or oxic conditions, rather than intermediate redox levels. Here we report anomalous cerium enrichments preserved in carbonate rocks across bathymetric basin transects from nine localities of the Nama Group, Namibia (~550-541 Ma). In combination with Fe-based redox proxies, these data suggest that low-oxygen conditions occurred in a narrow zone between well-oxygenated surface waters and fully anoxic deep waters. Although abundant in well-oxygenated environments, early skeletal animals did not occupy oxygen impoverished regions of the shelf, demonstrating that oxygen availability (probably >10 μM) was a key requirement for the development of early animal-based ecosystems.

  16. Low-oxygen waters limited habitable space for early animals.

    PubMed

    Tostevin, R; Wood, R A; Shields, G A; Poulton, S W; Guilbaud, R; Bowyer, F; Penny, A M; He, T; Curtis, A; Hoffmann, K H; Clarkson, M O

    2016-09-23

    The oceans at the start of the Neoproterozoic Era (1,000-541 million years ago, Ma) were dominantly anoxic, but may have become progressively oxygenated, coincident with the rise of animal life. However, the control that oxygen exerted on the development of early animal ecosystems remains unclear, as previous research has focussed on the identification of fully anoxic or oxic conditions, rather than intermediate redox levels. Here we report anomalous cerium enrichments preserved in carbonate rocks across bathymetric basin transects from nine localities of the Nama Group, Namibia (∼550-541 Ma). In combination with Fe-based redox proxies, these data suggest that low-oxygen conditions occurred in a narrow zone between well-oxygenated surface waters and fully anoxic deep waters. Although abundant in well-oxygenated environments, early skeletal animals did not occupy oxygen impoverished regions of the shelf, demonstrating that oxygen availability (probably >10 μM) was a key requirement for the development of early animal-based ecosystems.

  17. 75 FR 65507 - U.S.-Russia Polar Bear Commission Adopts an Annual Taking Limit for the Alaska-Chukotka Polar...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-25

    ... Fish and Wildlife Service U.S.-Russia Polar Bear Commission Adopts an Annual Taking Limit for the Alaska-Chukotka Polar Bear Population AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice. SUMMARY: On June 9, 2010, by unanimous vote, the U.S.-Russia Polar Bear Commission established by the...

  18. 26 CFR 1.401(e)-5 - Limitation of contribution and benefit bases to first $100,000 of annual compensation in case of...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... first $100,000 of annual compensation in case of plans covering self-employed individuals. 1.401(e)-5... of plans covering self-employed individuals. (a) General rules—General rule. (1) Under section 401(a... to special limitations for self-employed individuals); section 413(b)(7) (relating to...

  19. 26 CFR 1.401(e)-5 - Limitation of contribution and benefit bases to first $100,000 of annual compensation in case of...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... first $100,000 of annual compensation in case of plans covering self-employed individuals. 1.401(e)-5... of plans covering self-employed individuals. (a) General rules—General rule. (1) Under section 401(a... to special limitations for self-employed individuals); section 413(b)(7) (relating to...

  20. 26 CFR 1.401(e)-5 - Limitation of contribution and benefit bases to first $100,000 of annual compensation in case of...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... first $100,000 of annual compensation in case of plans covering self-employed individuals. 1.401(e)-5... covering self-employed individuals. (a) General rules—General rule. (1) Under section 401(a)(17), a plan... self-employed individuals); section 413(b)(7) (relating to determination of limitations provided...

  1. 26 CFR 1.401(e)-5 - Limitation of contribution and benefit bases to first $100,000 of annual compensation in case of...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... first $100,000 of annual compensation in case of plans covering self-employed individuals. 1.401(e)-5... of plans covering self-employed individuals. (a) General rules—General rule. (1) Under section 401(a... to special limitations for self-employed individuals); section 413(b)(7) (relating to...

  2. 26 CFR 1.401(e)-5 - Limitation of contribution and benefit bases to first $100,000 of annual compensation in case of...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... first $100,000 of annual compensation in case of plans covering self-employed individuals. 1.401(e)-5... of plans covering self-employed individuals. (a) General rules—General rule. (1) Under section 401(a... to special limitations for self-employed individuals); section 413(b)(7) (relating to...

  3. Depth-to-water area polygons, isopleths showing mean annual runoff, 1912-1963, and water-level altitude contours for the Humboldt River Basin, Nevada

    USGS Publications Warehouse

    Welborn, Toby L.; Medina, Rose L.

    2017-01-01

    This USGS data release represents the 1:500,000-scale geospatial data for the following publication:Eakin, T.E., and Lamke, R.D., 1966, Hydrologic reconnaissance of the Humboldt River basin, Nevada: Nevada Department of Conservation and Natural Resources, Water Resources Bulletin 32, 107 p.The data set consists of 3 separate items:1. Depth-to-water area polygons2. Isopleths showing mean annual runoff, 1912-19633. Water-level altitude contours

  4. Tree water status and growth of saplings and mature Norway spruce (Picea abies) at a dry distribution limit

    PubMed Central

    Oberhuber, Walter; Hammerle, Albin; Kofler, Werner

    2015-01-01

    We evaluated the size effect on stem water status and growth in Norway spruce (Picea abies (L.) Karst.) occurring at the edge of its natural range in a dry inner Alpine environment (750 m asl, Tyrol, Austria). Intra-annual dynamics of stem water deficit (ΔW), maximum daily shrinkage (MDS), and radial growth (RG) were compared among saplings (stem diameter/height: 2.2 cm/93 cm; n = 7) and mature adult trees (25 cm/12.7 m; n = 6) during 2014. ΔW, MDS, and RG were extracted from stem diameter variations, which were continuously recorded by automatic dendrometers and the influence of environmental drivers was evaluated by applying moving correlation analysis (MCA). Additionally, we used Morlet wavelet analysis to assess the differences in cyclic radial stem variations between saplings and mature trees. Results indicate that saplings and mature trees were experiencing water limitation throughout the growing season. However, saplings exhibited a more strained stem water status and higher sensitivity to environmental conditions than mature trees. Hence, the significantly lower radial increments in saplings (0.16 ± 0.03 mm) compared to mature trees (0.54 ± 0.14 mm) is related to more constrained water status in the former, affecting the rate and duration of RG. The wavelet analysis consistently revealed more distinct diurnal stem variations in saplings compared to mature trees. Intra-annual RG was most closely related to climate variables that influence transpiration, i.e., vapor pressure deficit, relative air humidity, and air temperature. MCA, however, showed pronounced instability of climate–growth relationships, which masked missing temporal or significant correlations when the entire study period (April–October) was considered. We conclude that an increase in evaporative demand will impair regeneration and long-term stability of drought-prone inner Alpine Norway spruce forests. PMID:26442019

  5. Tree water status and growth of saplings and mature Norway spruce (Picea abies) at a dry distribution limit.

    PubMed

    Oberhuber, Walter; Hammerle, Albin; Kofler, Werner

    2015-01-01

    We evaluated the size effect on stem water status and growth in Norway spruce (Picea abies (L.) Karst.) occurring at the edge of its natural range in a dry inner Alpine environment (750 m asl, Tyrol, Austria). Intra-annual dynamics of stem water deficit (ΔW), maximum daily shrinkage (MDS), and radial growth (RG) were compared among saplings (stem diameter/height: 2.2 cm/93 cm; n = 7) and mature adult trees (25 cm/12.7 m; n = 6) during 2014. ΔW, MDS, and RG were extracted from stem diameter variations, which were continuously recorded by automatic dendrometers and the influence of environmental drivers was evaluated by applying moving correlation analysis (MCA). Additionally, we used Morlet wavelet analysis to assess the differences in cyclic radial stem variations between saplings and mature trees. Results indicate that saplings and mature trees were experiencing water limitation throughout the growing season. However, saplings exhibited a more strained stem water status and higher sensitivity to environmental conditions than mature trees. Hence, the significantly lower radial increments in saplings (0.16 ± 0.03 mm) compared to mature trees (0.54 ± 0.14 mm) is related to more constrained water status in the former, affecting the rate and duration of RG. The wavelet analysis consistently revealed more distinct diurnal stem variations in saplings compared to mature trees. Intra-annual RG was most closely related to climate variables that influence transpiration, i.e., vapor pressure deficit, relative air humidity, and air temperature. MCA, however, showed pronounced instability of climate-growth relationships, which masked missing temporal or significant correlations when the entire study period (April-October) was considered. We conclude that an increase in evaporative demand will impair regeneration and long-term stability of drought-prone inner Alpine Norway spruce forests.

  6. Intra- and Inter-annual Fluorescence Intensity Variations in Drip Water, Heshang Cave, Central China: Implications for Speleothem Palaeoclimatology

    NASA Astrophysics Data System (ADS)

    Jin, L.; Hu, C.; Li, X.; Ruan, J.; Hartland, A.

    2015-12-01

    Cave drip water acts as a signal carrier for the soil-rock-air system leading to the capture of climatic and environmental information in stalagmites. This paper seeks to develop an understanding of the environmental and climatic factors which control fluorescence variations in dripwater from in Heshang Cave, Central China. This information is essential to unravelling the significance of organic fluorescence in stalagmites and its utility in quantitative paleoclimate reconstructions. On the seasonal time scale, drip water fluorescence is largely controlled by the decomposition and translocation of dissolved organic matter in the soil, related to climate factors like temperature and precipitation. On the inter-annual time scale, longer duration monitoring data in scarce, yet this is needed to fully comprehend the influence of climate in stalagmite fluorescence time series. This study presents nine consecutive years of monthly drip water fluorescence intensity and drip rate data from two perennial drip sites in Heshang Cave. Drip water fluorescence was generally characterized by intensities in spring/summer and low intensities in autumn/winter. In dry hydrologic years, little seasonality in fluorescence signals was observed, but the opposite was observed in wet years. On the inter-annual time scale, the annual mean intensities of drip water fluorescence positively correlated with local annual rainfall with a 1-year lag (R2HS4=0.94; R2HS6=0.74). This indicates that rainfall is the main control on total drip water fluorescence (integrating across a hydrologic year), despite significant degrees of intra-annual fluorescence variation being observed between wet and dry years. These findings are of direct relevance for paleoclimate reconstruction using fluorescence intensities in stalagmites from the Asian monsoon region. Key words: fluorescence; dissolved organic matter; drip water rates; seasonality; precipitation

  7. Using coagulation to restrict microbial re-growth in tap water by phosphate limitation in water treatment.

    PubMed

    Wen, Gang; Ma, Jun; Huang, Ting-Lin; Egli, Thomas

    2014-09-15

    Extensive microbial re-growth in a drinking water distribution system can deteriorate water quality. The limiting factor for microbial re-growth in a tap water produced by a conventional drinking water treatment plant in China was identified by determining the microbial re-growth potential (MRP) by adding different nutrients to stimulate growth of a natural microbial consortium as inoculum and flow-cytometric enumeration. No obvious change of MRP was found in tap water after addition of carbon, whereas, a 1- to 2-fold increase of MRP was observed after addition of phosphate (P). This clearly demonstrated that microbial re-growth in this tap water was limited by P. Most of the re-grown microbial flora (>85%) consisted of high nucleic acid content cells. A subsequent investigation of the MRP in the actual water treatment plant demonstrated that coagulation was the crucial step for decreasing MRP and producing P-limited water. Therefore, a comparison concerning the control of MRP by three different coagulants was conducted. It showed that all the three coagulants efficiently reduced the MRP and shifted the limitation regime from C to P, but the required dose was different. The study shows that it is feasible to restrict microbial re-growth by P limitation using coagulation in water treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Detection limits and cost comparisons of human- and gull-associated conventional and quantitative PCR assays in artificial and environmental waters

    USGS Publications Warehouse

    Riedel, Timothy E.; Zimmer-Faust, Amity G.; Thulsiraj, Vanessa; Madi, Tania; Hanley, Kaitlyn T.; Ebentier, Darcy L.; Byappanahalli, Muruleedhara N.; Layton, Blythe; Raith, Meredith; Boehm, Alexandria B.; Griffith, John F.; Holden, Patricia A.; Shanks, Orin C.; Weisberg, Stephen B.; Jay, Jennifer A.

    2014-01-01

    Some molecular methods for tracking fecal pollution in environmental waters have both PCR and quantitative PCR (qPCR) assays available for use. To assist managers in deciding whether to implement newer qPCR techniques in routine monitoring programs, we compared detection limits (LODs) and costs of PCR and qPCR assays with identical targets that are relevant to beach water quality assessment. For human-associated assays targeting Bacteroidales HF183 genetic marker, qPCR LODs were 70 times lower and there was no effect of target matrix (artificial freshwater, environmental creek water, and environmental marine water) on PCR or qPCR LODs. The PCR startup and annual costs were the lowest, while the per reaction cost was 62% lower than the Taqman based qPCR and 180% higher than the SYBR based qPCR. For gull-associated assays, there was no significant difference between PCR and qPCR LODs, target matrix did not effect PCR or qPCR LODs, and PCR startup, annual, and per reaction costs were lower. Upgrading to qPCR involves greater startup and annual costs, but this increase may be justified in the case of the human-associated assays with lower detection limits and reduced cost per sample.

  9. Detection limits and cost comparisons of human- and gull-associated conventional and quantitative PCR assays in artificial and environmental waters.

    PubMed

    Riedel, Timothy E; Zimmer-Faust, Amity G; Thulsiraj, Vanessa; Madi, Tania; Hanley, Kaitlyn T; Ebentier, Darcy L; Byappanahalli, Muruleedhara; Layton, Blythe; Raith, Meredith; Boehm, Alexandria B; Griffith, John F; Holden, Patricia A; Shanks, Orin C; Weisberg, Stephen B; Jay, Jennifer A

    2014-04-01

    Some molecular methods for tracking fecal pollution in environmental waters have both PCR and quantitative PCR (qPCR) assays available for use. To assist managers in deciding whether to implement newer qPCR techniques in routine monitoring programs, we compared detection limits (LODs) and costs of PCR and qPCR assays with identical targets that are relevant to beach water quality assessment. For human-associated assays targeting Bacteroidales HF183 genetic marker, qPCR LODs were 70 times lower and there was no effect of target matrix (artificial freshwater, environmental creek water, and environmental marine water) on PCR or qPCR LODs. The PCR startup and annual costs were the lowest, while the per reaction cost was 62% lower than the Taqman based qPCR and 180% higher than the SYBR based qPCR. For gull-associated assays, there was no significant difference between PCR and qPCR LODs, target matrix did not effect PCR or qPCR LODs, and PCR startup, annual, and per reaction costs were lower. Upgrading to qPCR involves greater startup and annual costs, but this increase may be justified in the case of the human-associated assays with lower detection limits and reduced cost per sample. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. [Soil water resource use limit in semi-arid loess hilly area].

    PubMed

    Guo, Zhong-sheng

    2010-12-01

    Taking Caragana korshinskii as test object, and by using neutron probe, a long term observation was conducted on the soil water and plant growth during the process of vegetation restoration in semi-arid loess hilly area. The results showed that after seeding on waste land, the capability of plant community in conserving soil and water was promoted with time, with the depth of roots to absorb and use soil water increased and the soil water content reduced. Then, the dried soil layer appeared, and its deepness and thickness increased with increasing plant age. Therefore, the plant use of soil water had a limit, soil water resource use limit, i.e., the soil water storage when the deepness of dried soil layer was equal to the largest depth that rain could recharge. In the C. korshinskii woodland in semi-arid loess hilly area, the soil water resource use limit in 0-290 cm layer was 249.4 mm. When the soil water storage in woodland was close or equal to the soil water resource use limit, effective measures should be taken to decrease soil evapotranspiration or increase soil water supply to ensure the sustainable water use of plant roots.

  11. New beach ridge type: severely limited fetch, very shallow water

    SciTech Connect

    Tanner, W.F.; Demirpolat, S.

    1988-09-01

    The southern end of Laguna Madre (Texas) north of the Rio Grande mouth is marked by very shallow water, wide tidal flats, lunettes, islands made of beach ridges, and lesser features. The number and variety of islands in the lagoon is remarkable. The lunettes (clay dunes) are made primarily of quartz sand and coarse silt. They are common 5-10 m high, irregular in shape, and steep sided. They were deposited from wind transport and did not migrate. Those that are islands in the lagoon predate present position of sea level. Islands made of beach ridges were built from the lagoon side. Photoanalysis, field work, and granulometry all show that this sand was not moved into these ridges by Gulf of Mexico waves. Trenches in 12 beach ridges showed horizontal bedding but neither low-angle nor steep cross-bedding (quite unlike swash-built beach ridges). The ridges were built by wind-tide lag effects, not from the swash. Therefore, these beach ridges are a new type, in addition to swash-built, eolian, and storm-surge ridges. Growth of the ridges appears to be completed.

  12. Annual production of burrowing mayfly nymphs (Hexagenia spp.) in U.S. waters of Lake St. Clair

    USGS Publications Warehouse

    Edsall, Thomas A.; Haas, Robert C.; Adams, Jean V.

    2001-01-01

    Burrowing mayfly nymphs (Hexagenia spp.) were sampled monthly, September through October 1995 and April through August 1996, with a standard Ponar grab (538 cm2 jaw opening) at 16 stations in U.S. waters of Lake St. Clair. Annual production (production, P) was 0 to 477 mg dry weight/m2 at three stations where pollution and sediment grain-size distribution limited the population, and was 738 to 5,255 mg dry weight/m2 at the other 13 stations. The highest production value measured for Hexagenia in Lake St. Clair was about three times higher than the highest value reported for other areas in the northern United States and Canada (39° to 53° North latitude). The production-mean annual biomass (biomass, B) ratio (P/B) for Hexagenia in Lake St. Clair in 1995–96 was described by the straight line P = 2.4 B (R2 = 0.94). Adding published P/B data for other North American populations changed the relation only slightly to P = 2.5B (R2 = 0.96). A P/B ratio of 2.5 is consistent with the expected value for an aquatic insect with a 2-year life cycle and overlapping cohorts, and these data suggest this relation has general applicability for estimating production of Hexagenia in the northern United States and Canada. Size-class and seasonal partitioning of Hexagenia biomass and production were evident in the data. Both biomass and production were highest among nymphs 16.0 mm and larger, and biomass was highest in October and again in June, immediately before the annual emergence of subimagos. The large size of the mature nymphs and the concentration of biomass and production among the larger nymphs in the population is consistent with their importance in the diets of many fishes in the northern United States and Canada.

  13. 25 CFR 171.510 - How does BIA calculate my annual operation and maintenance assessment if supplemental water is...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false How does BIA calculate my annual operation and maintenance assessment if supplemental water is available on the irrigation facility servicing my farm unit... IRRIGATION OPERATION AND MAINTENANCE Financial Matters: Assessments, Billing, and Collections § 171.510 How...

  14. Soil Water Balance and Vegetation Dynamics in two Water-limited Mediterranean Ecosystem on Sardinia under past and future climate change

    NASA Astrophysics Data System (ADS)

    Corona, R.; Montaldo, N.; Albertson, J. D.

    2016-12-01

    Water limited conditions strongly impacts soil and vegetation dynamics in Mediterranean regions, which are commonly heterogeneous ecosystems, characterized by inter-annual rainfall variability, topography variability and contrasting plant functional types (PFTs) competing for water use. Historical human influences (e.g., deforestation, urbanization) further altered these ecosystems. Sardinia island is a representative region of Mediterranean ecosystems. It is low urbanized except some plan areas close to the main cities where main agricultural activities are concentrated. Two contrasting case study sites are within the Flumendosa river basin (1700 km2). The first site is a typical grassland on an alluvial plan valley (soil depth > 2m) while the second is a patchy mixture of Mediterranean vegetation species (mainly wild olive trees and C3 herbaceous) that grow in a soil bounded from below by a rocky layer of basalt, partially fractured (soil depth 15 - 40 cm). In both sites land-surface fluxes and CO2 fluxes are estimated by the eddy correlation technique while soil moisture was continuously estimated with water content reflectometers, and periodically leaf area index (LAI) was estimated. The following objectives are addressed:1) pointing out the dynamics of land surface fluxes, soil moisture, CO2 and vegetation cover for two contrasting water-limited ecosystems; 2) assess the impact of the soil depth and type on the CO2 and water balance dynamics; 3) evaluate the impact of past and future climate change scenarios on the two contrasting ecosystems. For reaching the objectives an ecohydrologic model that couples a vegetation dynamic model (VDM), and a 3-component (bare soil, grass and woody vegetation) land surface model (LSM) has been used. Historical meteorological data are available from 1922 and hydro-meteorological scenarios are then generated using a weather generator. The VDM-LSM model predict soil water balance and vegetation dynamics for the generated

  15. 1994 Environmental monitoring drinking water and nonradiological effluent programs annual report

    SciTech Connect

    Andersen, B.D.; Brock, T.A.; Meachum, T.R.

    1995-10-01

    EG&G Idaho, Inc., initiated monitoring programs for drinking water in 1988 and for nonradiological parameters and pollutants in liquid effluents in 1985. These programs were initiated for the facilities operated by EG&G Idaho for the US Department of Energy at the Idaho National Engineering Laboratory. On October 1, 1994, Lockheed Idaho Technologies Company (LITCO) replaced EG&G Idaho as the prime contractor at the INEL and assumed responsibility for these programs. Section I discusses the general site characteristics, the analytical laboratories, and sampling methodology general to both programs. Section 2, the Drinking Water Program, tracks the bacteriological, chemical, and radiological parameters required by State and Federal regulations. This section describes the drinking water monitoring activities conducted at 17 LITCO-operated production wells and 11 distribution systems. It also contains all of the drinking water parameters detected and the regulatory limits exceeded during calendar year 1994. In addition, groundwater quality is discussed as it relates to contaminants identified at the wellhead for LITCO production wells. Section 3 discusses the nonradiological liquid effluent monitoring results for 27 liquid effluent streams. These streams are presented with emphasis on calendar year 1994 activities. All parameter measurements and concentrations were below the Resource Conservation and Recovery Act toxic characteristics limits.

  16. Long-term trend and multi-annual variability of water temperature in the pristine Bela River basin (Slovakia)

    NASA Astrophysics Data System (ADS)

    Pekárová, Pavla; Miklánek, Pavol; Halmová, Dana; Onderka, Milan; Pekár, Ján; Kučárová, Katarína; Liová, Soňa; Škoda, Peter

    2011-04-01

    SummaryBiological processes in surface waters appreciably depend on temperature of water. This paper summarizes our investigations of water temperature in the Bela River. The Bela River is a mountainous stream not influenced by direct human activities, draining the headwaters of the Vah River basin in the Tatra National Park (TANAP), Slovakia. Our primary aim was to identify the long-term trends and multi-annual variability of the annual water temperature at the Podbanske gauging station, using temperature readings taken at 7.00 am for the period of 50 years (1959-2008). Long-term mean of the annual water temperature of the Bela River at the Podbanske gauging station (922 m a.s.l.) was 4.2 °C, the air temperature at Podbanske meteorological station (972 m a.s.l.) was 5.0 °C. Both, air and water temperature, show an increasing trend. While the air temperature within 50-years increased significantly by 1.5 °C, in the case of water temperature this increase was merely by 0.12 °C. On November 19, 2004, a wind-throw brushed the investigated area with an aftermath of 15.4% destroyed forest in the Bela basin, mainly along the area adjacent to the river. Therefore, in the second part of the study, the impact of the riparian vegetation growing along the river banks was evaluated for two distinctive periods, i.e. the period prior and after the wind-throw. We statistically analysed the changes in water temperature on 6-year time series of daily water temperature (November 2001 through November 2007). The results presented herein may be useful for defining boundary values for surface water temperature, as required by the EC Water Framework Directive.

  17. Hydrologic effects of annually diverting 131,000 acre-feet of water from Dillon Reservoir, central Colorado

    USGS Publications Warehouse

    Alley, William M.; Bauer, D.P.; Veenhuis, J.E.; Brennan, Robert

    1979-01-01

    Because of the increased demands for water in eastern Colorado, principally in the urbanizing Denver metropolitan area, increased diversions of water from Dillon Reservoir are planned. Estimates of end-of-month storage in Dillon Reservoir, assuming the reservoir was in place and 131,000 acre-feet of water were diverted from the reservoir each year, were reconstructed by mass balance for the 1931-77 water years. Based on the analysis, the annual maximum end-of-month drawdown below the elevation at full storage would have averaged 54 feet. The maximum end-of-month drawdown below the elevation at full storage would have been 171 feet. The mean-annual discharge-weighted dissolved-solids concentrations in the Colorado River near Glenwood Springs and Cameo, Colo., and Cisco, Utah, for the 1942-77 water years, were computed assuming an annual diversion of 131,000 acre-feet of water from Dillon Reservoir. The average increases in the dissolved-solids concentrations with the 131 ,000-acre-foot diversion were 15 to 16 milligrams per liter at the three sites. (Woodard-USGS)

  18. Water use efficiency of perennial and annual bioenergy crops in central Illinois

    NASA Astrophysics Data System (ADS)

    Zeri, Marcelo; Hussain, Mir Zaman; Anderson-Teixeira, Kristina J.; Delucia, Evan; Bernacchi, Carl J.

    2013-06-01

    Sustainable bioenergy production depends upon the efficiency with which crops use available water to produce biomass and store carbon belowground. Therefore, water use efficiency (WUE; productivity vs. annual evapotranspiration, ET) is a key metric of bioenergy crop performance. We evaluate WUE of three potential perennial grass bioenergy crops, Miscanthus × giganteus (miscanthus), Panicum virgatum (switchgrass), and an assemblage of prairie species (28 species), and Zea mays-Glycine max rotation, during the establishment phase in Illinois. Ecosystem WUE (EWUE; net ecosystem productivity vs. ET) was highest in miscanthus, reaching a maximum value of 12.8 ± 0.3 kg ha-1 mm-1 in the third year, followed by switchgrass (7.5 ± 0.3 kg ha-1 mm-1) and prairie (3.9 ± 0.3 kg ha-1 mm-1); the row crop was the lowest. Besides EWUE, harvest-WUE (HWUE, harvested biomass vs. ET) and net biome productivity-WUE (BWUE, calculated as net ecosystem production - harvest vs. ET) were also estimated for all crops and years. After three years of establishment, HWUE and BWUE were highest in miscanthus (9.0 ± 2 and 3.8 ± 2.9 kg ha-1 mm-1, respectively) providing a net benefit to the carbon balance, while the row crops had a negative carbon balance and a negative BWUE. BWUE for maize/soybean indicate that this ecosystem would deplete the soil carbon stocks while using the water resources. Switchgrass had the second highest BWUE, while prairie was almost neutral indicating that long-term carbon sequestration for this agro-ecosystem would be sensitive to harvest timing with an early harvest removing more biomass, and thus carbon, from the field.

  19. Water resources data for North Carolina, water year 1995. Volume 2. Ground-water records. Water data report (Annual), 1 October 1994-30 September 1995

    SciTech Connect

    Smith, D.G.; George, E.D.; Breton, P.L.

    1996-06-01

    Water-resources data for the 1995 water year for North Carolina consist of records of ground-water levels and water quality of ground water; records of stage, discharge, and water quality of streams; and stage and contents of lakes and reservoirs. This report contains ground-water level data from 81 observation wells and ground-water quality data from 125 wells.

  20. Water resources data for North Carolina, water year 1993. Volume 2. Ground-water records. Water-data report (Annual), 1 October 1992-30 September 1993

    SciTech Connect

    Coble, R.W.; Smith, D.G.; Ragland, B.C.

    1994-04-13

    Water-resources data for the 1993 water year for North Carolina consist of records of ground-water levels and water quality of ground water; records of stage, discharge and water quality of streams; and stage and contents of lakes and reservoirs. This report contains ground-water level data from 82 observation wells and ground-water quality data from 41 wells.

  1. Compression Limit of Two-Dimensional Water Constrained in Graphene Nanocapillaries.

    PubMed

    Zhu, YinBo; Wang, FengChao; Bai, Jaeil; Zeng, Xiao Cheng; Wu, HengAn

    2015-12-22

    Evaluation of the tensile/compression limit of a solid under conditions of tension or compression is often performed to provide mechanical properties that are critical for structure design and assessment. Algara-Siller et al. recently demonstrated that when water is constrained between two sheets of graphene, it becomes a two-dimensional (2D) liquid and then is turned into an intriguing monolayer solid with a square pattern under high lateral pressure [ Nature , 2015 , 519 , 443 - 445 ]. From a mechanics point of view, this liquid-to-solid transformation characterizes the compression limit (or metastability limit) of the 2D monolayer water. Here, we perform a simulation study of the compression limit of 2D monolayer, bilayer, and trilayer water constrained in graphene nanocapillaries. At 300 K, a myriad of 2D ice polymorphs (both crystalline-like and amorphous) are formed from the liquid water at different widths of the nanocapillaries, ranging from 6.0 to11.6 Å. For monolayer water, the compression limit is typically a few hundred MPa, while for the bilayer and trilayer water, the compression limit is 1.5 GPa or higher, reflecting the ultrahigh van der Waals pressure within the graphene nanocapillaries. The compression-limit (phase) diagram is obtained at the nanocapillary width versus pressure (h-P) plane, based on the comprehensive molecular dynamics simulations at numerous thermodynamic states as well as on the Clapeyron equation. Interestingly, the compression-limit curves exhibit multiple local minima.

  2. The radiative role of ozone and water vapour in the temperature annual cycle in the tropical tropopause layer

    NASA Astrophysics Data System (ADS)

    Ming, Alison; Maycock, Amanda; Hitchcock, Peter; Haynes, Peter

    2017-04-01

    The prominent annual cycle in temperatures (with maximum peak to peak amplitude of 8 K around 70 hPa and 6 K at 90 hPa) is a key feature of the tropical tropopause layer (TTL). There is also a strong annual cycle observed in both ozone and water vapour in the TTL, with the latter understood as a consequence of the temperature annual cycle. The radiative contributions of the annual cycle in ozone and water vapour to the temperature annual cycle are studied, first with a seasonally evolving fixed dynamical heating calculation (SEFDH) where the dynamical heating is assumed to be unaffected by the radiative heating. In this framework, the variations in ozone and water vapour derived from satellite data lead to variations in temperature that are respectively in phase and out of phase with the observed annual cycle. The ozone contribution is at the upper range of previous calculations. This difference in phasing can be understood from the fact that an increase in water vapour cools the TTL, predominantly through enhanced local emission, whereas an increase in ozone warms the TTL, mostly through enhanced absorption of upwelling longwave radiation from the troposphere. The relative phasing of the water vapour and ozone effects on temperature is further influenced by the fact that for water vapour there is a strong non-local effect on temperatures from variations in concentrations occurring in lower layers of the TTL. In contrast, for ozone it is the local variations in concentration that have the strongest impact on local temperature variations. The factors that determine the vertical structure of the annual cycle in temperature are also examined. Radiative damping time scales are shown to maximize over a broad layer centred on the cold point. Non-radiative processes in the upper troposphere are inferred to impose a strong constraint on temperature perturbations below 130 hPa. These effects, combined with the annual cycles in dynamical and radiative heating, which both

  3. Investigation of decreases in annual streamflows in the water source and destination of the central route of China's South to North Water Diversion Project

    NASA Astrophysics Data System (ADS)

    Liu, X.; Liu, C.

    2013-12-01

    The central route of China's South to North Water Diversion Project is planned to divert water from the Danjiangkou Reservoir to Beijing. Currently, the main local surface water source for Beijing is the Miyun Reservoir. Annual runoffs in both of the Danjiangkou Reservoir Basin and Miyun Reservoir Basin decreased significantly from 1956 to 2009. For the Danjiangkou Reservoir Basin, average annual runoff was 428.5 mm from 1956 to 1989, while it decreased to 328.2 mm from 1990 to 2009. For the Miyun Reservoir Basin, the average annual runoff was 101.8 mm from 1956 to 1979 and decreased to 40.8 mm from 1980 to 2009. We investigate that climatic fluctuation was the main reason of the decreasing runoff in the Danjiangkou Reservoir Basin, while human influences were the main reason of the decreasing runoff in the Miyun Reservoir Basin. We speculate that the declining runoff in a water source and a destination for that source would increase the probability of a simultaneous dry year for the two regions. The increasing probability of a simultaneous dry year indicates an increasing frequency of years in which Beijing urgently needs diversion water while the Danjiangkou Reservoir will not be able to meet the demands. This situation could threaten the success of the entire water diversion project and the sustainable development of Beijing. We suggest that the water diversion from the Danjiangkou Reservoir should be conducted in an adaptive manner to avoid such an adverse consequence.

  4. Recycling harvest water to cultivate Chlorella zofingiensis under nutrient limitation for biodiesel production.

    PubMed

    Zhu, L D; Takala, J; Hiltunen, E; Wang, Z M

    2013-09-01

    Harvest water recycling for Chlorella zofingiensis re-cultivation under nutrient limitation was investigated. Using 100% harvest water, four cultures were prepared: Full medium, P-limited medium, N-limited medium and N- and P-limited medium, while another full medium was also prepared using 50% harvest water. The results showed that the specific growth rate and biomass productivity ranged from 0.289 to 0.403 day(-1) and 86.30 to 266.66 mg L(-1) day(-1), respectively. Nutrient-limited cultures witnessed much higher lipid content (41.21-46.21% of dry weight) than nutrient-full cultures (26% of dry weight). The N- and P-limited medium observed the highest FAME yield at 10.95% of dry weight, while the N-limited culture and P-limited culture shared the highest biodiesel productivity at 20.66 and 19.91 mg L(-1) day(-1), respectively. The experiment on harvest water recycling times demonstrated that 100% of the harvest water could be recycled twice with the addition of sufficient nutrients.

  5. Seasonal and annual distribution of carbon, water and energy fluxes of irrigated agroecosystems in inland Australia

    NASA Astrophysics Data System (ADS)

    Vote, C. E.; Hafeez, M.; Charlton, P.; Hall, A.

    2012-12-01

    The extent to which agroecosystems contribute to the carbon cycle as net sources or sinks of atmospheric carbon dioxide remains relatively uncertain and it appears that in-depth studies of integrated water, carbon and energy fluxes of irrigated broad-acre crops for common Australian conditions and soil types are yet to be reported. Therefore, this study focuses on the use of eddy covariance methodologies to determine the empirical relationship between these fluxes for three of the major irrigated crops grown in inland Australia; maize, rice and wheat. Here we present the uptake or release of carbon dioxide in relation to evapotranspiration at different phenological stages for each crop at the field scale; and the extrapolation of these to provide an estimate of fluxes at the regional scale based on similar soil types. The annual distribution of the mass and energy exchange was also determined and the level of similarities and key differences between the carbon fluxes and energy partitioning under these particular climatic conditions were compared to similar studies of irrigated broad-acre agriculture production conducted elsewhere in the world.

  6. Comprehensive cooling water study annual report. Volume VIII: semi-aquatic vertebrates, Savannah River Plant

    SciTech Connect

    Gladden, J.B.; Lower, M.W.; Mackey, H.E.; Specht, W.L.; Wilde, E.W.

    1985-07-01

    Several semi-aquatic vertebrate species are regularly observed in ''natural'' and ''post-thermal'' environments at SRP. Fewer species are regularly observed in thermally-altered areas. Yellow-bellied slider turtles, however, seem to thrive in areas of mildly elevated temperatures where they exhibit larger female body size than specimens from some ambient temperature areas of the SRP. Yellow-bellied slider turtles are the predominant species of semi-aquatic turtle on the SRP. Research conducted during 1984 was aimed toward examination of the activity levels of these animals, and their movement patterns within and among thermally- and nonthermally-altered wetlands on the SRP. Additional studies conducted on movement patterns of turtles in relation to reproduction examined emigration rates in five species of turtles during years of normal rainfall compared with a year of drought at a Carolina Bay. Studies of body size of slider turtles showed that animals inhabiting thermally-altered areas attain larger sizes than do individuals from ambient areas, presumably because the elevated temperatures allow for longer annual activity and feeding periods. Slider turtles from coastal, and from thermally- and nonthermally-altered inland populations, were examined for relationships between growth and clutch parameters. Slider turtles from an area of radioactive contamination were also studied for a determination of strontium-90 and cesium-137 bio-elimination. Studies of the brown water snake in the vicinity of Steel Creek and in the vicinity of Upper Three Runs Creek showed that these animals are primarily diurnal and prefer cool water temperatures. Preliminary sampling was initiated in 1984 to determine the structure of the Steel Creek snake community. 65 refs., 5 figs., 26 tabs.

  7. Dynamics of three types of annual plants competing for water and light

    NASA Astrophysics Data System (ADS)

    Pȩkalski, Andrzej; Szwabiński, Janusz

    2013-02-01

    We present and discuss a Monte Carlo model describing the dynamics of three types of annual plants which have different tolerances to shade and drought. External conditions (water and light) fluctuate around some values which are our control parameters and which decide how many resources the system receives. The plants compete with their nearest neighbours for the resources, however not in the same way. We show that for certain ranges of the control parameters a coexistence of the three species is observed. We discuss how the characteristics of the the plants - their number, germination, biomass or the number of nearest neighbours, depend on the two control parameters characterising external conditions. We show that elimination is done at the level of adult plants, not seedlings. We find also cooperative behaviour of plants in difficult conditions, as observed in field studies and we propose an explanation for this fact. Apart from plants tolerating shade but requiring more water and those tolerating drought but needing more light, which are common in nature, we introduce a third species with intermediary demands. We investigate under what conditions this new species could dominate and whether the total number of plants, regardless of their type, is larger with or without the intermediate plant. We show that in our model, like in nature, systems with two kinds of plants with opposite characteristics are, in general, as effective as a system with an additional third type of plants. We show that two contradictory hypotheses made by biologists, concerning the demands of plants in drought and shade, could be both true, however in different regimes.

  8. Programs for generating data tables for the annual water-resources data report of the U.S. Geological Survey

    USGS Publications Warehouse

    Mason, R.R.; Hill, C.L.

    1988-01-01

    The U.S. Geological Survey has developed software that interfaces with the Automated Data Processing System to facilitate and expedite preparation of the annual water-resources data report. This software incorporates a feature that prepares daily values tables and appends them to previously edited files containing station manuscripts. Other features collate the merged files with miscellaneous sections of the report. The report is then printed as page-size, camera-ready copy. All system components reside on a minicomputer; this provides easy access and use by remote field offices. Automation of the annual report preparation process results in significant savings of labor and cost. Use of the system for producing the 1986 annual report in the North Carolina District realized a labor savings of over two man-months. A fully implemented system would produce a greater savings and speed release of the report to users.

  9. Some simulation estimates of mean annual increment of Douglas-fir: results, limitations, and implications for management.

    Treesearch

    Robert O. Curtis

    1994-01-01

    Patterns of development of mean annual increment in relation to age predicted by the widely used DFSIM, SPS, TASS, and ORGANON simulators were examined. Although predictions differ considerably among simulators for portions of the range of sites, ages, and treatments, comparisons indicated that (1) culmination is relatively late, (2) the curve is relatively flat in the...

  10. Development of solid electrolytes for water electrolysis at intermediate temperatures. Task 3 report; Annual report

    SciTech Connect

    Linkous, C.A.; Anderson, R.; Kopitzke, R.W.

    1995-12-01

    This project is an attempt to synthesize and fabricate proton exchange membranes for hydrogen production via water electrolysis that can take advantage of the better kinetic and thermodynamic conditions that exist at higher temperatures. Current PEM technology is limited to the 125--150 C range. Based on previous work evaluating thermohydrolytic stability, some 5 families of polymers were chosen as viable candidates: polyether ketones, polyether sulfones, fluorinated polyimides, polybenzimidazoles, and polyphenyl quinoxalines. Several of these have been converted into ionomers via sulfonation and fashioned into membranes for evaluation. In particular, the sulfonated polyetheretherketone, or SPEEK, was tested for water uptake, thermo-conductimetric analysis, and performance as the solid electrolyte material in an electrolysis cell. Results comparable to commercial perfluorocarbon sulfonates were obtained.

  11. Water availability limits tolerance of apical damage in the Chilean tarweed Madia sativa

    NASA Astrophysics Data System (ADS)

    Gonzáles, Wilfredo L.; Suárez, Lorena H.; Molina-Montenegro, Marco A.; Gianoli, Ernesto

    2008-07-01

    Plant tolerance is the ability to reduce the negative impact of herbivory on plant fitness. Numerous studies have shown that plant tolerance is affected by nutrient availability, but the effect of soil moisture has received less attention. We evaluated tolerance of apical damage (clipping that mimicked insect damage) under two watering regimes (control watering and drought) in the tarweed Madia sativa (Asteraceae). We recorded number of heads with seeds and total number of heads as traits related to fitness. Net photosynthetic rate, water use efficiency, number of branches, shoot biomass, and the root:shoot biomass ratio were measured as traits potentially related to tolerance via compensatory responses to damage. In the drought treatment, damaged plants showed ≈43% reduction in reproductive fitness components in comparison with undamaged plants. In contrast, there was no significant difference in reproductive fitness between undamaged and damaged plants in the control watering treatment. Shoot biomass was not affected by apical damage. The number of branches increased after damage in both water treatments but this increase was limited by drought stress. Net photosynthetic rate increased in damaged plants only in the control watering treatment. Water use efficiency increased with drought stress and, in plants regularly watered, also increased after damage. Root:shoot ratio was higher in the low water treatment and damaged plants tended to reduce root:shoot ratio only in this water treatment. It is concluded that water availability limits tolerance to apical damage in M. sativa, and that putative compensatory mechanisms are differentially affected by water availability.

  12. Limit of detection and limit of quantification development procedures for organochlorine pesticides analysis in water and sediment matrices

    PubMed Central

    2013-01-01

    Background Reliable values for method validity of organochlorine pesticides determination were investigated, in water by solid phase extraction and in sediment by Soxhlet extraction, followed by gas chromatography equipped with an electron capture detector. Organochlorine pesticides are categorized as Persistent Organic Pollutants. Hence, critical decisions to control exposure to these chemicals in the environment are based on their levels in different media; it is important to find valid qualitative and quantitative results for these components. In analytical chemistry, internal quality procedures are applied to produce valid logical results. Result In this study, 18 organochlorine pesticides were targeted for analysis and determination in water and river sediment. Experiments based on signal-to-noise ratio, calibration curve slope and laboratory fortified blank methods were conducted to determine the limits of qualification and quantification. The data were compared with each other. The limitation values, following Laboratory Fortified Blank, showed significant differences in the signal-to-noise ratio and calibration curve slope methods, which are assumed in the results for the sample concentration factor to be 1,000 times in water and 10 times in sediment matrices. The method detection limit values were found to be between 0.001 and 0.005 μg/L (mean of 0.002 ± 0.001) and 0.001 and 0.005 μg/g (mean of 0.001 ± 0.001). The quantification limits were found to be between 0.002 and 0.016 μg/L (mean of 0.006 ± 0.004) and 0.003 and 0.017 μg/g (mean of 0.005 ± 0.003 μg/L) for water and sediment, respectively, based on the laboratory fortified blank method. Because of different slopes in the calibration methods, it was also found that the limitation values for some components from the internal standard were higher than from external standard calibration, because in the latter a factor for injection efficiency is applied for calibration

  13. Modified Feddes type stress reduction function for modeling root water uptake: Accounting for limited aeration and low water potential

    NASA Astrophysics Data System (ADS)

    Peters, Andre; Durner, Wolfgang; Iden, Sascha C.

    2017-04-01

    Modeling water flow in the soil-plant-atmosphere continuum with the Richards equation requires a model for the sink term describing water uptake by plant roots. Despite recent progress in developing process-based models of water uptake by plant roots and water flow in aboveground parts of vegetation, effective models of root water uptake are widely applied and necessary for large-scale applications. Modeling root water uptake consists of three steps, (i) specification of the spatial distribution of potential uptake, (ii) reduction of uptake due to various stress sources, and (iii) enhancement of uptake in part of the simulation domain to describe compensation. We discuss the conceptual shortcomings of the frequently used root water uptake model of Feddes and suggest a simple but effective improvement of the model. The improved model parametrizes water stress in wet soil by a reduction scheme which is formulated as function of air content where water stress due to low soil water potential is described by the original approach of Feddes. The improved model is physically more consistent than Feddes' model because water uptake in wet soil is limited by aeration which is a function of water content. The suggested modification is particularly relevant for simulations in heterogeneous soils, because stress parameters are uniquely defined for the entire simulation domain, irrespective of soil texture. Numerical simulations of water flow and root water uptake in homogeneous and stochastic heterogeneous soils illustrate the effect of the new model on root water uptake and actual transpiration. For homogeneous fine-textured soils, root water uptake never achieves its potential rate. In stochastic heterogeneous soil, water uptake is more pronounced at the interfaces between fine and coarse regions which has potential implications for plant growth, nutrient uptake and depletion.

  14. Regional annual water yield from forest lands and its response to potential deforestation across the southeastern United States

    NASA Astrophysics Data System (ADS)

    Sun, G.; McNulty, S. G.; Lu, J.; Amatya, D. M.; Liang, Y.; Kolka, R. K.

    2005-07-01

    Regional water yield at a meso-scale can be estimated as the difference between precipitation input and evapotranspiration output. Forest water yield from the southeastern US varies greatly both in space and time. Because of the hot climate and high evapotranspiration, less than half of the annual precipitation that falls on forest lands is available for stream flow in this water-rich region. Water yield is highest in the mountainous regions that receive the highest precipitation and have the lowest air temperature, and the lowest in the coastal regions that are dominated by wetlands receiving moderate rainfall but high evapotranspiration. Water resource management for both floods and droughts demands an accurate estimation of water yield from forests. Projected climate and land use changes further increase the variability of water yield in the region. The objectives of this study were to (1) develop a simple annual water yield modeling procedure by testing and calibrating a generalized global evapotranspiration model, (2) to apply the validated model to estimate regional forest water yield and to predict potential water yield response to forest removal. Hydrologic databases at a watershed-scale and a regional-scale were developed for model development, calibration, and validation. We applied the water yield model to the southern region by integrating land cover and high resolution climate databases by using a Geographic Information System (GIS). The model developed in this paper can be used to examine the spatial and temporal variability for water yield and predict the effects of climate and land cover changes at the regional scale.

  15. Stocking of Offsite Waters for Hungry Horse Dam Mitigation Creston National Fish Hatchery, FY 2006 Annual Report.

    SciTech Connect

    Hooley, Sharon

    2009-03-20

    A total of 350,000, M012 strain, westslope cutthroat trout (WCT) eggs were received from Montana Fish Wildlife & Parks (MFWP), Washoe Park State Fish Hatchery in June of 2005 to accomplish this fishery management objective. These eggs were incubated, hatched and reared entirely inside the hatchery nursery building using a protected well water supply. Fish grew according to schedule and survival was excellent. The hatchery achieved a 0.78 feed fed to pounds gained conversion ratio for this group of WCT. Not all of the progenies from this fish lot were used for Hungry Horse Dam Fishery Mitigation Implementation. Some were used for other regional fishery management projects. Westslope cutthroat trout were reared using approved fish culture techniques as recommended in the USFWS Fish Hatchery Management Handbook and also utilizing a regimen adapted for hatchery specific site conditions. The fish health for these WCT was very good. Survival from first feeding fry stage to stocking was 79%. The hatchery had an annual fish health inspection performed by the USFWS Bozeman Fish Health Center in mid March of 2006. This inspection found all fish lots at Creston to be disease free. The Montana State Fish Health Board has placed the hatchery under a limited quarantine since May of 2005 due to an epizootic of Furunculosis. This classification has allowed the Creston NFH to stock disease free fish in locations approved by regional fish managers. The hatchery has been working with the State Fish Pathologist to remove the limited quarantine classification from the facility. Although fish health for all station fish lots remains disease free, MFWP has asserted it will not remove the limited quarantine until the new influent water treatment system, including the ultraviolet disinfection unit, is running full time, year round. The USFWS is working to secure the additional funding necessary to operate the treatment building year round. Distribution of the WCT took place from March

  16. Lower Limits of Water Use By Cotton, Maize, and Grain Sorghum in Three Great Plains Soils

    USDA-ARS?s Scientific Manuscript database

    Accurate knowledge of the amount of soil water available for crop use helps agricultural producers select cropping and irrigation management strategies that maximize crop yields. Using neutron attenuation, we measured the lower limits of soil water content (LL, in m**3 m**-3) at harvest (three seas...

  17. 30 CFR 817.42 - Hydrologic balance: Water quality standards and effluent limitations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Hydrologic balance: Water quality standards and effluent limitations. 817.42 Section 817.42 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.42 Hydrologic balance: Water quality standards and effluent...

  18. 30 CFR 816.42 - Hydrologic balance: Water quality standards and effluent limitations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Hydrologic balance: Water quality standards and effluent limitations. 816.42 Section 816.42 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-SURFACE MINING ACTIVITIES § 816.42 Hydrologic balance: Water quality standards and effluent...

  19. 30 CFR 817.42 - Hydrologic balance: Water quality standards and effluent limitations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Hydrologic balance: Water quality standards and effluent limitations. 817.42 Section 817.42 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.42 Hydrologic balance: Water quality standards and effluent...

  20. 30 CFR 817.42 - Hydrologic balance: Water quality standards and effluent limitations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Hydrologic balance: Water quality standards and effluent limitations. 817.42 Section 817.42 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.42 Hydrologic balance: Water quality standards and effluent...

  1. 30 CFR 816.42 - Hydrologic balance: Water quality standards and effluent limitations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Hydrologic balance: Water quality standards and effluent limitations. 816.42 Section 816.42 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-SURFACE MINING ACTIVITIES § 816.42 Hydrologic balance: Water quality standards and effluent...

  2. 30 CFR 817.42 - Hydrologic balance: Water quality standards and effluent limitations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Hydrologic balance: Water quality standards and effluent limitations. 817.42 Section 817.42 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.42 Hydrologic balance: Water quality standards and effluent...

  3. 30 CFR 817.42 - Hydrologic balance: Water quality standards and effluent limitations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Hydrologic balance: Water quality standards and effluent limitations. 817.42 Section 817.42 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.42 Hydrologic balance: Water quality standards and effluent...

  4. 30 CFR 816.42 - Hydrologic balance: Water quality standards and effluent limitations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Hydrologic balance: Water quality standards and effluent limitations. 816.42 Section 816.42 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-SURFACE MINING ACTIVITIES § 816.42 Hydrologic balance: Water quality standards and effluent...

  5. 30 CFR 816.42 - Hydrologic balance: Water quality standards and effluent limitations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Hydrologic balance: Water quality standards and effluent limitations. 816.42 Section 816.42 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-SURFACE MINING ACTIVITIES § 816.42 Hydrologic balance: Water quality standards and effluent...

  6. 30 CFR 816.42 - Hydrologic balance: Water quality standards and effluent limitations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Hydrologic balance: Water quality standards and effluent limitations. 816.42 Section 816.42 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-SURFACE MINING ACTIVITIES § 816.42 Hydrologic balance: Water quality standards and effluent...

  7. Evaluation of Management of Water Release for Painted Rocks Reservoir, Bitterroot River, Montana, 1984 Annual Report.

    SciTech Connect

    Lere, Mark E.

    1984-11-01

    Baseline fisheries and habitat data were gathered during 1983 and 1984 to evaluate the effectiveness of supplemental water releases from Painted Rocks Reservoir in improving the fisheries resource in the Bitterroot River. Discharge relationships among main stem gaging stations varied annually and seasonally. Flow relationships in the river were dependent upon rainfall events and the timing and duration of the irrigation season. Daily discharge monitored during the summers of 1983 and 1984 was greater than median values derived at the U.S.G.S. station near Darby. Supplemental water released from Painted Rocks Reservoir totaled 14,476 acre feet in 1983 and 13,958 acre feet in 1984. Approximately 63% of a 5.66 m{sup 3}/sec test release of supplemental water conducted during April, 1984 was lost to irrigation withdrawals and natural phenomena before passing Bell Crossing. A similar loss occurred during a 5.66 m{sup 3}/sec test release conducted in August, 1984. Daily maximum temperature monitored during 1984 in the Bitterroot River averaged 11.0, 12.5, 13.9 and 13.6 C at the Darby, Hamilton, Bell and McClay stations, respectively. Chemical parameters measured in the Bitterroot River were favorable to aquatic life. Population estimates conducted in the Fall, 1983 indicated densities of I+ and older rainbow trout (Salmo gairdneri) were significantly greater in a control section than in a dewatered section (p < 0.20). Numbers of I+ and older brown trout (Salmo trutta) were not significantly different between the control and dewatered sections (p > 0.20). Population and biomass estimates for trout in the control section were 631/km and 154.4 kg/km. In the dewatered section, population and biomass estimates for trout were 253/km and 122.8 kg/km. The growth increments of back-calculated length for rainbow trout averaged 75.6 mm in the control section and 66.9mm in the dewatered section. The growth increments of back-calculated length for brown trout averaged 79.5 mm in the

  8. Winter water relations at the upper elevational limits of hemlock on Mt. Ascutney, Vermont

    Treesearch

    Chandra B. Vostral; Richard L. Boyce

    2000-01-01

    Winter water relations have been monitored in hemlock (Tsuga canadensis (L.) Carr.) at their upper elevational limits for three winters, 1997, 1998, and 1999, on Mt. Ascutney, Vermont. Hemlock and white pine trees (Pinus strobus L.) reach their elevational limit on Mt. Ascutney at 640 m (2100?), while the summit has an elevation of...

  9. Aquifer-test results, direction of ground-water flow, and 1984-90 annual ground-water pumpage for irrigation, lower Big Lost River Valley, Idaho

    USGS Publications Warehouse

    Bassick, M.D.; Jones, M.L.

    1992-01-01

    The study area (see index map of Idaho), part of the Big Lost River drainage basin, is at the northern side of the eastern Snake River Plain. The lower Big Lost River Valley extends from the confluence of Antelope Creek and the Big Lost River to about 4 mi south of Arco and encompasses about 145 mi2 (see map showing water-level contours). The study area is about 18 mi long and, at its narrowest, 4 mi wide. Arco, Butte City, and Moore, with populations of 1,016, 59, and 190, respectively, in 1990, are the only incorporated towns. The entire study area, except the extreme northwestern part, is in Butte City. The study area boundary is where alluvium and colluvium pinch out and abut against the White Knob Mountains (chiefly undifferentiated sedimentary rock with lesser amounts of volcanic rock) on the west and the Lost River Range (chiefly sedimentary rock) on the east. Gravel and sand in the valley fill compose the main aquifer. The southern boundary is approximately where Big Lost River valley fill intercalates with or abuts against basalt of the Snake River Group. Spring ground-water levels and flow in the Big Lost River depend primarily on temperature and the amount and timing of precipitation within the entire drainage basin. Periods of abundant water supply and water shortages are, therefore, related to the amount of annual precipitation. Surface reservoir capacity in the valley (Mackay Reservoir, about 20 mi northwest of Moore) is only 20 percent of the average annual flow of the Big Lost River (Crosthwaite and others, 1970, p. 3). Stored surface water is generally unavailable for carryover from years of abundant water supply to help relieve drought conditions in subsequent years. Many farmers have drilled irrigation wells to supplement surface-water supplies and to increase irrigated acreage. Average annual flow of the Big Lost River below Mackay Reservoir near Mackay (gaging station 13127000, not shown) in water years 1905, 1913-14, and 1920-90 was about 224

  10. Changes in baseflow patterns in water-limited shale oil and gas regions: the Eagle Ford play

    NASA Astrophysics Data System (ADS)

    Arciniega, S.; Brena-Naranjo, J. A.; Hernández-Espriú, A.; Pedrozo-Acuña, A.

    2016-12-01

    Quantifying and analyzing the contribution of groundwater from shallow aquifers to rivers as baseflow is very important for water supply and riverine ecosystem health, especially in water-limited catchments. Baseflow depends on the water available (precipitation), vegetation (land use, water use), aquifer properties and water-table depth. In this context, human activities such as groundwater abstraction for multiple purposes can alter the relationship between aquifer storage and baseflow. In this study, we analyzed observed changes in baseflow patterns of 40 catchments located across the Eagle Ford shale gas/oil play (Texas) during the period 1986-2015. The Eagle Ford sedimentary formation is actually the largest shale oil producing region in the US with large production in shale gas. Intensive unconventional resources extraction in the Eagle Ford play started in 2009 and gas/oil production increased faster than in other plays, accompanied by a rise in groundwater consumption for HF purposes. Spatial and temporal impacts on baseflow at the Eagle Ford play derived from HF were assessed by means of different patterns such as baseflow hydrograph separation, flow-duration curves, empirical storage-discharge relationships and streamflow recession curve analysis. A comparison during different periods of water use for HF activities was performed: pre-development period (1986-2000); moderate period (2001-2008); and intensive period (2009-2015). The pre-development period was considered as a baseline and catchments located inside and outside the play area were separately analyzed. The results show negative changes on baseflow patterns during the intensive HF period that were not observed during the moderate period, especially in catchments located inside the play. These changes were also characterized by a decline on mean annual baseflow volume and shorter hydrograph recession times, that led to a shift in the streamflow regime in some catchments from perennial to

  11. Will water scarcity in semiarid regions limit hydraulic fracturing of shale plays?

    NASA Astrophysics Data System (ADS)

    Scanlon, Bridget R.; Reedy, Robert C.; Nicot, Jean Philippe

    2014-12-01

    There is increasing concern about water constraints limiting oil and gas production using hydraulic fracturing (HF) in shale plays, particularly in semiarid regions and during droughts. Here we evaluate HF vulnerability by comparing HF water demand with supply in the semiarid Texas Eagle Ford play, the largest shale oil producer globally. Current HF water demand (18 billion gallons, bgal; 68 billion liters, bL in 2013) equates to ˜16% of total water consumption in the play area. Projected HF water demand of ˜330 bgal with ˜62 000 additional wells over the next 20 years equates to ˜10% of historic groundwater depletion from regional irrigation. Estimated potential freshwater supplies include ˜1000 bgal over 20 yr from recharge and ˜10 000 bgal from aquifer storage, with land-owner lease agreements often stipulating purchase of freshwater. However, pumpage has resulted in excessive drawdown locally with estimated declines of ˜100-200 ft in ˜6% of the western play area since HF began in 2009-2013. Non-freshwater sources include initial flowback water, which is ≤5% of HF water demand, limiting reuse/recycling. Operators report shifting to brackish groundwater with estimated groundwater storage of 80 000 bgal. Comparison with other semiarid plays indicates increasing brackish groundwater and produced water use in the Permian Basin and large surface water inputs from the Missouri River in the Bakken play. The variety of water sources in semiarid regions, with projected HF water demand representing ˜3% of fresh and ˜1% of brackish water storage in the Eagle Ford footprint indicates that, with appropriate management, water availability should not physically limit future shale energy production.

  12. Analytical steady-state solutions for water-limited cropping systems using saline irrigation water

    USDA-ARS?s Scientific Manuscript database

    Due to the diminishing availability of good quality water for irrigation, it is increasingly important that irrigation and salinity management tools be able to target submaximal crop yields and support the use of marginal quality waters. In this work, we present a steady-state irrigated systems mod...

  13. Effect of tillage practices on least limiting water range in Northwest India

    NASA Astrophysics Data System (ADS)

    Kahlon, Meharban S.; Chawla, Karitika

    2017-04-01

    Tillage practices affect mechanical and hydrological characteristics of soil and subsequently the least limiting water range. This quality indicator under the wheat-maize system of northwest India has not been studied yet. The treatments included four tillage modes, namely conventional tillage, no-tillage without residue, no-tillage with residue, and deep tillage as well as three irrigation regimes based on the irrigation water and pan evaporation ratio i.e. 1.2, 0.9, and 0.6. The experiment was conducted in a split plot design with three replications. At the end of cropping system, the mean least limiting water range (m3 m-3) was found to be highest in deep tillage (0.26) and lowest in notillage without residue (0.15). The field capacity was a limiting factor for the upper range of the least limiting water range beyond soil bulk density 1.41 Mg m-3 and after that 10% air filled porosity played a major role. However, for the lower range, the permanent wilting point was a critical factor beyond soil bulk density 1.50 Mg m-3 and thereafter, the penetration resistance at 2 MPa becomes a limiting factor. Thus, deep tillage under compaction and no-tillage with residue under water stress is appropriate practice for achieving maximum crop and water productivity.

  14. Photosynthetic limitations in response to water stress and recovery in Mediterranean plants with different growth forms.

    PubMed

    Galmés, Jeroni; Medrano, Hipólito; Flexas, Jaume

    2007-01-01

    * Whether photosynthesis is limited during water stress and recovery because of diffusive or biochemical factors is still open to debate, and apparent contradictions appear when various studies on species with different growth forms are compared. * Ten Mediterranean species, representing different growth forms, were subjected to different levels of water stress, the most severe followed by rewatering. A quantitative limitation analysis was applied to estimate the effects of water stress on stomatal (S(L)), mesophyll conductance (MC(L)) and biochemical limitations (B(L)). * Results confirmed a general pattern of photosynthetic response to water stress among C(3) plants when stomatal conductance (g(s)) is used as a reference parameter. As g(s) values decreased from a maximum to approx. 0.05 mol H(2)O m(-2) s(-1), the total photosynthetic limitation rose from 0 to approx. 70%, and this was caused by a progressive increase of both S(L) and MC(L) limitations, while B(L) remained negligible. When lower values of g(s) were achieved (total photosynthetic limitation increased from 70 to 100%), the contribution of S(L) declined, while MC(L) still increased and B(L) contributed significantly (20-50%) to the total limitation. * Photosynthetic recovery of severely stressed plants after rewatering showed a dominant role of MC(L), irrespective of the degree of photosynthesis recovery.

  15. Analytical steady-state solutions for water-limited cropping systems using saline irrigation water

    NASA Astrophysics Data System (ADS)

    Skaggs, T. H.; Anderson, R. G.; Corwin, D. L.; Suarez, D. L.

    2014-12-01

    Due to the diminishing availability of good quality water for irrigation, it is increasingly important that irrigation and salinity management tools be able to target submaximal crop yields and support the use of marginal quality waters. In this work, we present a steady-state irrigated systems modeling framework that accounts for reduced plant water uptake due to root zone salinity. Two explicit, closed-form analytical solutions for the root zone solute concentration profile are obtained, corresponding to two alternative functional forms of the uptake reduction function. The solutions express a general relationship between irrigation water salinity, irrigation rate, crop salt tolerance, crop transpiration, and (using standard approximations) crop yield. Example applications are illustrated, including the calculation of irrigation requirements for obtaining targeted submaximal yields, and the generation of crop-water production functions for varying irrigation waters, irrigation rates, and crops. Model predictions are shown to be mostly consistent with existing models and available experimental data. Yet the new solutions possess advantages over available alternatives, including: (i) the solutions were derived from a complete physical-mathematical description of the system, rather than based on an ad hoc formulation; (ii) the analytical solutions are explicit and can be evaluated without iterative techniques; (iii) the solutions permit consideration of two common functional forms of salinity induced reductions in crop water uptake, rather than being tied to one particular representation; and (iv) the utilized modeling framework is compatible with leading transient-state numerical models.

  16. Influencing factors for household water quality improvement in reducing diarrhoea in resource-limited areas.

    PubMed

    Zin, Thant; Mudin, Kamarudin D; Myint, Than; Naing, Daw K S; Sein, Tracy; Shamsul, B S

    2013-01-01

    Water and sanitation are major public health issues exacerbated by rapid population growth, limited resources, disasters and environmental depletion. This study was undertaken to study the influencing factors for household water quality improvement for reducing diarrhoea in resource-limited areas. Data were collected from articles and reviews from relevant randomized controlled trials, new articles, systematic reviews and meta-analyses from PubMed, World Health Organization (WHO), United Nations Children's Fund (UNICEF) and WELL Resource Centre For Water, Sanitation And Environmental Health. Water quality on diarrhoea prevention could be affected by contamination during storage, collection and even at point-of-use. Point-of-use water treatment (household-based) is the most cost-effective method for prevention of diarrhoea. Chemical disinfection, filtration, thermal disinfection, solar disinfection and flocculation and disinfection are five most promising household water treatment methodologies for resource-limited areas. Promoting household water treatment is most essential for preventing diarrhoeal disease. In addition, the water should be of acceptable taste, appropriate for emergency and non-emergency use.

  17. Potential for savings in compliance costs for reducing ground-level ozone possible by instituting seasonal versus annual nitric oxide emission limits

    SciTech Connect

    Lookman, A.A.

    1996-12-31

    Ground-level ozone is formed in the atmosphere from its precursor emissions, namely nitric oxide (NO{sub x}) and volatile organic compounds (VOC), with its rate of formation dependent on atmospheric conditions. Since ozone levels tend to be highest during the summer months, seasonal controls of precursors have been suggested as a means of reducing the costs of decreasing ozone concentrations to acceptable levels. This paper attempts to quantify what the potential savings if seasonal control were instituted for coal-fired power plants, assuming that only commercially available NO{sub x} control technologies are used. Cost savings through seasonal control is measured by calculating the total annualized cost of NO{sub x} removal at a given amount of seasonal control for different target levels of annual control. For this study, it is assumed that trading of NO{sub x} emissions will be allowed, as has been proposed by the Ozone Transportation Commission (OTC). The problem has been posed as a binary integer linear programming problem, with decision variables being which control to use at each power plant. The results indicate that requiring annual limits which are lower than seasonal limits can substantially reduce compliance costs. These savings occur because requiring stringent compliance only on a seasonal basis allows power plants to use control methods for which the variable costs are paid for only part of the year, and through the use of gas-based controls, which are much cheaper to operate in the summer months.

  18. Multiscale assessment of water limitations on forest carbon cycling in the western United States

    NASA Astrophysics Data System (ADS)

    Berner, L. T.; Law, B. E.

    2016-12-01

    Water is a key environmental constraint on carbon uptake, storage, and release by forests in the western United States. Climate in this region is becoming warmer and drier, thus highlighting the need to better understand how forest carbon cycling responds to variation in water availability. Here, we describe how forest carbon cycling varied spatially along local to regional gradients in climatic water availability. We examined local variation in net primary productivity (NPP) and aboveground biomass (AGB) using 12 intensive field plots in Oregon's Cascade Mountains. Regional analysis of forest NPP and AGB was based on federal forest inventories (>8,000 plots) in Washington, Oregon, and California, multiple biomass maps and MODIS NPP (2003-2012). We also quantified annual forest AGB mortality due to bark beetles and fires across the region from 2003-2012 by combining several disturbance and biomass data sets. Over each spatial extent, forest NPP and AGB increased curvilinearly with average growing-year climate moisture index, computed as the cumulative difference between precipitation and potential evapotranspiration from October-September and averaged over preceding decades. Thus, climatic water availability strongly constrains forest carbon uptake and storage, particularly in the driest areas, but also in the wettest. Forest AGB mortality rates from bark beetles and fires peaked in moderately dry forests and then declining rapidly in the wettest areas. Annual forest AGB mortality from bark beetles was about twice as high as from fires. Bark beetle impacts were most pronounced in the Rock Mountains, while fire impacts were most pronounced in western portion of the region. Our multiscale analysis based on field inventory and remote sensing data sets demonstrates that climatic water availability is a key environmental constraint on forest carbon cycling in the western US. Consequently, continued warming and drying can be expected to have substantial impacts on forest

  19. Regression method for estimating long-term mean annual ground-water recharge rates from base flow in Pennsylvania

    USGS Publications Warehouse

    Risser, Dennis W.; Thompson, Ronald E.; Stuckey, Marla H.

    2008-01-01

    A method was developed for making estimates of long-term, mean annual ground-water recharge from streamflow data at 80 streamflow-gaging stations in Pennsylvania. The method relates mean annual base-flow yield derived from the streamflow data (as a proxy for recharge) to the climatic, geologic, hydrologic, and physiographic characteristics of the basins (basin characteristics) by use of a regression equation. Base-flow yield is the base flow of a stream divided by the drainage area of the basin, expressed in inches of water basinwide. Mean annual base-flow yield was computed for the period of available streamflow record at continuous streamflow-gaging stations by use of the computer program PART, which separates base flow from direct runoff on the streamflow hydrograph. Base flow provides a reasonable estimate of recharge for basins where streamflow is mostly unaffected by upstream regulation, diversion, or mining. Twenty-eight basin characteristics were included in the exploratory regression analysis as possible predictors of base-flow yield. Basin characteristics found to be statistically significant predictors of mean annual base-flow yield during 1971-2000 at the 95-percent confidence level were (1) mean annual precipitation, (2) average maximum daily temperature, (3) percentage of sand in the soil, (4) percentage of carbonate bedrock in the basin, and (5) stream channel slope. The equation for predicting recharge was developed using ordinary least-squares regression. The standard error of prediction for the equation on log-transformed data was 9.7 percent, and the coefficient of determination was 0.80. The equation can be used to predict long-term, mean annual recharge rates for ungaged basins, providing that the explanatory basin characteristics can be determined and that the underlying assumption is accepted that base-flow yield derived from PART is a reasonable estimate of ground-water recharge rates. For example, application of the equation for 370

  20. Limited effectiveness of household sand filters for removal of arsenic from well water in North Vietnam.

    PubMed

    Ilmiawati, Cimi; Thang, Nguyen Dinh; Iida, Machiko; Maeda, Masao; Ohnuma, Shoko; Yajima, Ichiro; Ohgami, Nobutaka; Oshino, Reina; Al Hossain, M M Aeorangajeb; Ninomiya, Hiromasa; Kato, Masashi

    2016-12-01

    Since well water utilized for domestic purposes in the Red River Delta of North Vietnam has been reported to be polluted by arsenic, barium, iron, and manganese, household sand filters consisting of various components are used. Information regarding the effectiveness of various sand filters for removal of the four toxic elements in well water is limited. In this study, arsenic levels in 13/20 of well water samples and 1/7 of tap water samples exceeded World Health Organization (WHO) health-based guideline value for drinking water. Moreover, 2/20, 6/20, and 4/20 of well water samples had levels exceeding the present and previous guideline levels for barium, iron, and manganese, respectively. Levels of iron and manganese, but not arsenic, in well water treated by sand filters were lower than those in untreated water, although previous studies showed that sand filters removed all of those elements from water. A low ratio of iron/arsenic in well water may not be sufficient for efficient removal of arsenic from household sand filters. The levels of barium in well water treated by sand filters, especially a filter composed of sand and charcoal, were significantly lower than those in untreated water. Thus, we demonstrated characteristics of sand filters in North Vietnam.

  1. Energy and Water Fluxes in Heterogeneous Mediterranean Water-limited Ecosystems

    NASA Astrophysics Data System (ADS)

    Detto, M.; Katul, G.; Mancini, M.

    2005-12-01

    Research efforts in distributed eco-hydrologic models often fall in one of two categories: prognostic, in which predictions of root-zone soil moisture content and land surface fluxes is required for a projected radiative and precipitation forcing time series, or diagnostic in which the relationship between soil water status and atmospheric water vapor demand is to be derived for the various components of the landscape. The latter relationships are now receiving broad attention in climate change, hydrological, and ecological studies of arid and semi-arid ecosystems. This interest is now a central focus given the recognition that the component latent heat flux sensitivity to soil moisture decline can directly impact plant productivity, carbon and nutrient cycling, and ground water recharge. With projected shifts in precipitation statistics, mainly towards increased desertification, the "stability" of these ecosystems is highly dependent on their ability to uptake water at low soil moisture Here, we determine the relationship between soil water status and atmospheric water vapor demand for patchy landscapes within a semi-arid ecosystems using a combination remote sensing products and field experiments. In particular, we investigate how VIS/NIR measurements, in conjunction with standard micrometeorological data and ground based thermal infrared thermometers, provide "diagnostic" hydrologic relationship between soil water content and potential evapo-transpiration for the various components of the landscape. These experiments were conducted in the Orroli site, situated in the mid-west of Sardinia (Italy) within the Flumendosa river watershed, which is considered one of the most important water supply resources to the island. The landscape is a mixture of Mediterranean patchy vegetation types: trees, including wild olives (/Olea sylvestris/) and cork oaks (/Quercus suber/), different shrubs (/Asparagus acutifolius, Rubus ulmifolius/) and herbaceous species (/Asphodelus

  2. Optimal demand reponse to water pricing policies under limited water supply in irrigation: a case study

    NASA Astrophysics Data System (ADS)

    Grießbach, Ulkrike; Stange, Peter; Schuetze, Niels

    2015-04-01

    Due to climate change, extreme weather conditions such as droughts may have an increasing impact on irrigated agriculture. To cope with the higher demand of water, a new decision support framework is developed which focuses on an integrated management of both irrigation water supply and demand. For modeling the regional water demand, local stochastic water demand functions are used which are derived from optimized agronomic response on farms scale. These functions take into account different soil types, crops, stochastically generated climate scenarios considering different economic conditions, e.g., variable and fixed costs. This generic approach enables the consideration of both multiple crops at farm scale as well as of the aggregated response to water pricing at a regional scale for full and deficit irrigation systems. Within the SAPHIR (SAxonian Platform for High Performance IRrigation) project a prototype of a decision support system is developed and applied for a case study in Saxony which helps to evaluate combined water supply and demand management policies on a regional level.

  3. Effects of Alder Mine on the Water, Sediments, and Benthic Macroinvertebrates of Alder Creek, 1998 Annual Report.

    SciTech Connect

    Peplow, Dan

    1999-05-28

    The Alder Mine, an abandoned gold, silver, copper, and zinc mine in Okanogan County, Washington, produces heavy metal-laden effluent that affects the quality of water in a tributary of the Methow River. The annual mass loading of heavy metals from two audits at the Alder Mine was estimated to exceed 11,000 kg per year. In this study, water samples from stations along Alder Creek were assayed for heavy metals by ICP-AES and were found to exceed Washington State's acute freshwater criteria for cadmium (Cd), copper (Cu), selenium (Se), and zinc (Zn).

  4. Vegetation Dynamics and Soil Water Balance Interactions in a Water-limited Mediterranean Ecosystem on Sardinia Under Climate Change Scenarios

    NASA Astrophysics Data System (ADS)

    Montaldo, N.; Albertson, J. D.

    2009-12-01

    Mediterranean ecosystems are commonly heterogeneous savanna-like ecosystems, with contrasting plant functional types (PFT) competing for the water use. At the same time the structure and function of the vegetation regulates the exchange of mass, energy and momentum across the biosphere-atmosphere interface, influencing strongly the soil water budget. Mediterranean regions suffer water scarcity produced in part by natural (e.g., climate variations) influences. For instance, in the Flumendosa basin water reservoir system, which plays a primary role in the water supply for much of southern Sardinia, the average annual input from stream discharge in the latter part of the 20th century was less than half the historic average rate. The precipitation over the Flumendosa basin has decreased, but not at such a drastic rate as the discharge, suggesting a marked non-linear response of discharge to precipitation changes. Indeed, precipitation decreased in winter months, which are crucial for reservoirs recharge through runoff. The IPCC models predicts a further increase of drought in the Mediterranean region, increasing the uncertainty on the future of the water resources system of these regions. Hence, there is the need to investigate the role of the PFT vegetation dynamics on the soil water budget of these ecosystems in the context of the climate change, and predict hydrologic variables for climate change scenarios. The case study is in the Flumendosa basin. The site landscape is a mixture of Mediterranean patchy vegetation types: trees, including wild olives and cork oaks, different shrubs and herbaceous species. An extensive field campaign started in May 2003. Six years of data are available now. Land-surface fluxes and CO2 fluxes are estimated by an eddy correlation technique based micrometeorological tower. Soil moisture profiles were also continuously estimated using water content reflectometers and gravimetric method, and periodically leaf area index (LAI) PFTs are

  5. Soil Water Balance and Vegetation Dynamics in a Water-limited Mediterranean Ecosystem on Sardinia under climate change scenarios

    NASA Astrophysics Data System (ADS)

    Montaldo, Nicola; Cortis, Clorinda; Albertson, John D.

    2010-05-01

    Mediterranean ecosystems are commonly heterogeneous savanna-like ecosystems, with contrasting plant functional types (PFT) competing for the water use. At the same time the structure and function of the vegetation regulates the exchange of mass, energy and momentum across the biosphere-atmosphere interface, influencing strongly the soil water budget. Mediterranean regions suffer water scarcity produced in part by natural (e.g., climate variations) influences. For instance, in the Flumendosa basin water reservoir system, which plays a primary role in the water supply for much of southern Sardinia, the average annual input from stream discharge in the latter part of the 20th century was less than half the historic average rate. The precipitation over the Flumendosa basin has decreased, but not at such a drastic rate as the discharge, suggesting a marked non-linear response of discharge to precipitation changes. Indeed, precipitation decreased in winter months, which are crucial for reservoirs recharge through runoff. The IPCC models predicts a further increase of drought in the Mediterranean region, increasing the uncertainty on the future of the water resources system of these regions. Hence, there is the need to investigate the role of the PFT vegetation dynamics on the soil water budget of these ecosystems in the context of the climate change, and predict hydrologic variables for climate change scenarios. The case study is in the Flumendosa basin. The site landscape is a mixture of Mediterranean patchy vegetation types: trees, including wild olives and cork oaks, different shrubs and herbaceous species. An extensive field campaign started in May 2003. More than six years of data of a micrometeorological tower are available now. Land-surface fluxes and CO2 fluxes are estimated by the eddy correlation technique based micrometeorological tower. Soil moisture profiles were also continuously estimated using water content reflectometers and gravimetric method, and

  6. Unravelling the limits to tree height: a major role for water and nutrient trade-offs.

    PubMed

    Cramer, Michael D

    2012-05-01

    Competition for light has driven forest trees to grow exceedingly tall, but the lack of a single universal limit to tree height indicates multiple interacting environmental limitations. Because soil nutrient availability is determined by both nutrient concentrations and soil water, water and nutrient availabilities may interact in determining realised nutrient availability and consequently tree height. In SW Australia, which is characterised by nutrient impoverished soils that support some of the world's tallest forests, total [P] and water availability were independently correlated with tree height (r = 0.42 and 0.39, respectively). However, interactions between water availability and each of total [P], pH and [Mg] contributed to a multiple linear regression model of tree height (r = 0.72). A boosted regression tree model showed that maximum tree height was correlated with water availability (24%), followed by soil properties including total P (11%), Mg (10%) and total N (9%), amongst others, and that there was an interaction between water availability and total [P] in determining maximum tree height. These interactions indicated a trade-off between water and P availability in determining maximum tree height in SW Australia. This is enabled by a species assemblage capable of growing tall and surviving (some) disturbances. The mechanism for this trade-off is suggested to be through water enabling mass-flow and diffusive mobility of P, particularly of relatively mobile organic P, although water interactions with microbial activity could also play a role.

  7. Uncertainty analysis of a spatially-explicit annual water-balance model: case study of the Cape Fear catchment, NC

    NASA Astrophysics Data System (ADS)

    Hamel, P.; Guswa, A. J.

    2014-10-01

    There is an increasing demand for assessment of water provisioning ecosystem services. While simple models with low data and expertise requirements are attractive, their use as decision-aid tools should be supported by uncertainty characterization. We assessed the performance of the InVEST annual water yield model, a popular tool for ecosystem service assessment based on the Budyko framework. Our study involved the comparison of ten subcatchments in the Cape Fear watershed, NC, ranging in size and land use configuration. We analyzed the model sensitivity to the eco-hydrological parameters and the effect of extrapolating a lumped theory to a fully distributed model. Comparison of the model predictions with observations and with a lumped water balance model confirmed that the model is able to represent differences in land uses. Our results also emphasize the effect of climate input errors, especially annual precipitation, and errors in the eco-hydrological parameter Z, which are both comparable to the model structure uncertainties. In practice, our case study supports the use of the model for predicting land use change effect on water provisioning, although its use for identifying areas of high water yield will be influenced by precipitation errors. While the results are inherently local, analysis of the model structure suggests that many insights from this study will hold globally. Further work toward characterization of uncertainties in such simple models will help identify the regions and decision contexts where the model predictions may be used with confidence.

  8. Uncertainty analysis of a spatially explicit annual water-balance model: case study of the Cape Fear basin, North Carolina

    NASA Astrophysics Data System (ADS)

    Hamel, P.; Guswa, A. J.

    2015-02-01

    There is an increasing demand for assessment of water provisioning ecosystem services. While simple models with low data and expertise requirements are attractive, their use as decision-aid tools should be supported by uncertainty characterization. We assessed the performance of the InVEST annual water yield model, a popular tool for ecosystem service assessment based on the Budyko hydrological framework. Our study involved the comparison of 10 subcatchments ranging in size and land-use configuration, in the Cape Fear basin, North Carolina. We analyzed the model sensitivity to climate variables and input parameters, and the structural error associated with the use of the Budyko framework, a lumped (catchment-scale) model theory, in a spatially explicit way. Comparison of model predictions with observations and with the lumped model predictions confirmed that the InVEST model is able to represent differences in land uses and therefore in the spatial distribution of water provisioning services. Our results emphasize the effect of climate input errors, especially annual precipitation, and errors in the ecohydrological parameter Z, which are both comparable to the model structure uncertainties. Our case study supports the use of the model for predicting land-use change effect on water provisioning, although its use for identifying areas of high water yield will be influenced by precipitation errors. While some results are context-specific, our study provides general insights and methods to help identify the regions and decision contexts where the model predictions may be used with confidence.

  9. Inter- and intra-annual variation of water footprint of crops and blue water scarcity in the Yellow River basin (1961-2009)

    NASA Astrophysics Data System (ADS)

    Zhuo, La; Mekonnen, Mesfin M.; Hoekstra, Arjen Y.; Wada, Yoshihide

    2016-01-01

    The Yellow River Basin (YRB), the second largest river basin of China, has experienced a booming agriculture over the past decades. But data on variability of and trends in water consumption, pollution and scarcity in the YRB are lacking. We estimate, for the first time, the inter- and intra-annual water footprint (WF) of crop production in the YRB for the period 1961-2009 and the variation of monthly scarcity of blue water (ground and surface water) for 1978-2009, by comparing the blue WF of agriculture, industry and households in the basin to the maximum sustainable level. Results show that the average overall green (from rainfall) and blue (from irrigation) WFs of crops in the period 2001-2009 were 14% and 37% larger, respectively, than in the period 1961-1970. The annual nitrogen- and phosphorus-related grey WFs (water required to assimilate pollutants) of crop production grew by factors of 24 and 36, respectively. The green-blue WF per ton of crop reduced significantly due to improved crop yields, while the grey WF increased because of the growing application of fertilizers. The ratio of blue to green WF increased during the study period resulting from the expansion of irrigated agriculture. In the period 1978-2009, the annual total blue WFs related to agriculture, industry and households varied between 19% and 52% of the basin's natural runoff. The blue WF in the YRB generally peaks around May-July, two months earlier than natural peak runoff. On average, the YRB faced moderate to severe blue water scarcity during seven months (January-July) per year. Even in the wettest month in a wet year, about half of the area of the YRB still suffered severe blue water scarcity, especially in the basin's northern part.

  10. Sensitivity of stream flow droughts, water shortage and water stress events to ENSO driven inter-annual climate variability at the global scale

    NASA Astrophysics Data System (ADS)

    Veldkamp, Ted I. E.; Aerts, Jeroen C. J. H.; Ward, Philip J.

    2014-05-01

    Governments and institutions managing water resources have to adapt constantly to regional drought, water shortage and water stress conditions, being caused by climate change, socio-economic developments and/or climate variability. Taking into account the impact of climate variability is important as in some regions it may outweigh long-term climate change or socio-economic developments, especially on a time scale of a few years up to a few decades. As governments and water management institutions apply planning horizons up to a decade with respect to management of adaptation strategies, inter-annual climate variability is especially relevant. A number of studies have estimated the impacts of climate variability on stream flow droughts on a local, continental or global scale. Others have focused on the role of long term climate change and socio-economic trends on blue water availability, shortage and stress. However, a global assessment of the influence of inter-annual climate variability on stream flow droughts, blue water availability, shortage and stress together has not yet been carried out, despite its importance for adaptation planning. To address this issue, we assessed the influence of ENSO-driven climate variability on stream flow droughts, blue water availability, and shortage and stress events at the global scale. Within this contribution we focused on El Nino Southern Oscillation's (ENSO) impact as ENSO is the most dominant source of inter-annual climate variability, impacting climate and society. We carried out this assessment through the following steps: (1) used daily discharge and run-off time-series (0.5º x 0.5º) of three WATCH forced global hydrological models (WaterGAP, PCR-GLOBWB, and STREAM); (2) in combination with time-series of population counts and monthly water demands we calculated monthly and yearly stream flow drought, water availability, water shortage and water stress per Food Producing Unit (FPU) for the period 1960-2000; and (3

  11. 40 CFR 130.7 - Total maximum daily loads (TMDL) and individual water quality-based effluent limitations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... individual water quality-based effluent limitations. 130.7 Section 130.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS WATER QUALITY PLANNING AND MANAGEMENT § 130.7 Total maximum daily loads (TMDL) and individual water quality-based effluent limitations. (a) General. The...

  12. 40 CFR 130.7 - Total maximum daily loads (TMDL) and individual water quality-based effluent limitations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... individual water quality-based effluent limitations. 130.7 Section 130.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS WATER QUALITY PLANNING AND MANAGEMENT § 130.7 Total maximum daily loads (TMDL) and individual water quality-based effluent limitations. (a) General. The...

  13. Least Limiting Water Range of soils in the Colonia Agrícola de Turen, Venezuela

    NASA Astrophysics Data System (ADS)

    Perez, Maiby Yolanda; Florentino de Andreu, Adriana

    2013-04-01

    Soil physical degradation is a major problem affecting the soil quality for crops production in Venezuelan agricultural areas. The least limiting water range (LLWR) is considered a soil physical quality index defined as the range in soil water content within which the limitations to plant response associated with water potential, poor aeration and high mechanical resistance are minimal. The study was carried out to characterize the LLWR and to determine the LLWR response to structural changes on soils of the Colonia Agricola de Turen, Venezuela. The soils were cropped with maize under different tillage systems (no tillage, conventional and conventional - fallow) and non-cropped under native forest. Hundred and seventy undisturbed samples were taken from specific sites under each of the above soil conditions to determine the water retention curve, the soil resistance curve and bulk density. Disturbed samples were also taken from each site to determine particle size and organic matter content. Pedotransfer functions relating the water retention curve and soil resistance curve with particle size distribution, organic matter content and bulk density were developed and use to calculate the LLWR for each site. According to the results, soil physical degradation under conventional tillage and high clay content had the highest negative impact on the LLWR. For this case (silty clay loam soil), the LLWR became narrower due to the lower water content associated with poor aeration and the higher water content associated with high mechanical resistance. In contrast, for non degraded soils with high sand content (sandy loam) the LLWR showed the highest values associated with the water content at field capacity and the water content at permanent wilting point, both the upper and lower critical limits of LLWR. For silty loam and loam soils the LLWR declined with increasing bulk density and clay content associated with water content at field capacity and water content at high

  14. Detection limits of pollutants in water for PGNAA using Am Be source

    NASA Astrophysics Data System (ADS)

    Khelifi, R.; Amokrane, A.; Bode, P.

    2007-09-01

    A basic PGNAA facility with an Am-Be neutron source is described to analyze the pollutants in water. The properties of neutron flux were determined by MCNP calculations. In order to determine the efficiency curve of a HPGe detector, the prompt-gamma rays from chlorine were used and an exponential curve was fitted. The detection limits for typical water sample are also estimated using the statistical fluctuations of the background level in the areas of recorded the prompt-gamma spectrum.

  15. Least limiting water range of Udox soil under degraded pastures on different sun-exposed faces

    NASA Astrophysics Data System (ADS)

    Passos, Renato Ribeiro; Marciano da Costa, Liovando; Rodrigues de Assis, Igor; Santos, Danilo Andrade; Ruiz, Hugo Alberto; Guimarães, Lorena Abdalla de Oliveira Prata; Andrade, Felipe Vaz

    2017-07-01

    The efficient use of water is increasingly important and proper soil management, within the specificities of each region of the country, allows achieving greater efficiency. The South and Caparaó regions of Espírito Santo, Brazil are characterized by relief of `hill seas' with differences in the degree of pasture degradation due to sun exposure. The objective of this study was to evaluate the least limiting water range in Udox soil under degraded pastures with two faces of exposure to the sun and three pedoenvironments. In each pedoenvironment, namely Alegre, Celina, and Café, two areas were selected, one with exposure on the North/West face and the other on the South/East face. In each of these areas, undisturbed soil samples were collected at 0-10 cm depth to determine the least limiting water range. The exposed face of the pasture that received the highest solar incidence (North/West) presented the lowest values in least limiting water range. The least limiting water range proved to be a physical quality indicator for Udox soil under degraded pastures.

  16. A partition-limited model for the plant uptake of organic contaminants from soil and water

    USGS Publications Warehouse

    Chiou, C.T.; Sheng, G.; Manes, M.

    2001-01-01

    In dealing with the passive transport of organic contaminants from soils to plants (including crops), a partition-limited model is proposed in which (i) the maximum (equilibrium) concentration of a contaminant in any location in the plant is determined by partition equilibrium with its concentration in the soil interstitial water, which in turn is determined essentially by the concentration in the soil organic matter (SOM) and (ii) the extent of approach to partition equilibrium, as measured by the ratio of the contaminant concentrations in plant water and soil interstitial water, ??pt (??? 1), depends on the transport rate of the contaminant in soil water into the plant and the volume of soil water solution that is required for the plant contaminant level to reach equilibrium with the external soil-water phase. Through reasonable estimates of plant organic-water compositions and of contaminant partition coefficients with various plant components, the model accounts for calculated values of ??pt in several published crop-contamination studies, including near-equilibrium values (i.e., ??pt ??? 1) for relatively water-soluble contaminants and lower values for much less soluble contaminants; the differences are attributed to the much higher partition coefficients of the less soluble compounds between plant lipids and plant water, which necessitates much larger volumes of the plant water transport for achieving the equilibrium capacities. The model analysis indicates that for plants with high water contents the plant-water phase acts as the major reservoir for highly water-soluble contaminants. By contrast, the lipid in a plant, even at small amounts, is usually the major reservoir for highly water-insoluble contaminants.

  17. Preservation of residual renal function with limited water removal in hemodialysis patients.

    PubMed

    Diao, Zongli; Zhang, Dongliang; Dai, Wendi; Ding, Jiaxiang; Zhang, Aihua; Liu, Wenhu

    2011-01-01

    Residual renal function (RRF) is of paramount importance for hemodialysis (HD) adequacy, morbidity, and mortality. Some studies have shown that overhydration is beneficial for preservation of RRF, but it can also increase the probability of adverse events such as hypertension and heart failure in HD patients. To determine the optimal amount of dehydration, we performed HD with limited water removal in HD patients. Eighteen HD patients included in this self-controlled study underwent HD with limited water removal. Water removal volume was determined by a previous volume as follows. Total water removal volume was divided into levels: ≤3.0, 3.0-9.0, and >9.0 L per week. Water removal was performed to obtain dry weight in the last dialysis, and was performed three times with a ratio of 1:1:2 and 2:2:3, respectively. Urine volume, endogenous creatinine clearance rate, Kt/V, hemoglobin, and serum albumin were recorded before and after the study at 3, 6, 9, and 12 months. The follow-up period was 12 months. Ten patients withdrew from the study because of adverse events including hypertension (n = 3), heart failure (n = 3), angina (n = 1), polycystic kidney rupture (n = 1), obvious edema (n = 1), and one patient had too much interdialytic weight gain to continue. As a result, we stopped this study after 1 month. Our data suggest that the preservation of RRF with limited water removal in HD patients must be interpreted with caution.

  18. Scaling-up leaf monoterpene emissions from a water limited Quercus ilex woodland

    NASA Astrophysics Data System (ADS)

    Lavoir, A. V.; Duffet, C.; Mouillot, F.; Rambal, S.; Ratte, J. P.; Schnitzler, J. P.; Staudt, M.

    2011-06-01

    Mediterranean ecosystems are large emitters of biogenic volatile organic compounds (BVOC), and recent studies illustrate how water stress can decrease these emissions even during hot summer. We present here a spatially explicit modelling experiment of BVOC emissions in a water-limited Mediterranean Region in Southern France dominated by Quercus ilex forests. Emission rates were estimated daily using a leaf-level emission model with appropriate up-scaling procedures. The model was based on Guenther's empirical equations, where we inserted effects for water limitation and seasonality observed from field measurements. Up-scaling from leaves to canopy was performed using Sellers' theory. For each grid cell, climate variables were interpolated daily from meteorological stations. Incoming solar radiation was measured at one site and extrapolated for the all region based on slope and aspect. Soil properties were derived from pedological maps as well as a digital elevation model, while soil water content was evaluated daily using a bucket-type model. We estimated monoterpene emissions from Q. ilex woodlands to be 16 kt yr -1 (on average), with most emissions occurring in the summer. When including the water-limitation module, yearly emissions were 50% of the initial estimates, with a significant decrease in the number of days with BVOC high emission peaks. This result highlights the importance of water control on determining air pollution peaks in Mediterranean areas and the need for scaling procedure in this area with its large range of strong emitter species.

  19. Greenhouse gas emissions of drained fen peatlands in Belarus are controlled by water table, land use, and annual weather conditions

    NASA Astrophysics Data System (ADS)

    Burlo, Andrei; Minke, Merten; Chuvashova, Hanna; Augustin, Jürgen; Hoffmann, Mathias; Narkevitch, Ivan

    2014-05-01

    Drainage of peatlands causes strong emission of the greenhouse gases (GHG) CO2 and N2O, sometimes combined with a weak CH4 uptake. In Belarus drained peatlands occupy about 1505000 ha or more than 7.2 % of the country area. Joosten (2009) estimates CO2 emission from degraded peatlands in Belarus as 41.3 Mt yr-1 what equals to 47 % of total anthropogenic greenhouse gases (GHGs) emission of country in 2011. However, it could not be checked if these numbers are correct since there are no GHG measurements on these sites up to now. Therefore we studied the GHG emissions with the closed chamber approach in four peatlands situated in central and southern Belarus over a period from August 2010 to August 2012. The measurements comprised eight site types representing different water level conditions, and ranging from grassland and arable land over abandoned fields and peat cuts to near-natural sedge fens. Fluxes of CH4 and N2O were determined using the close-chamber approach every second week in snow free periods and every fourth week during winter time. The annual emissions were calculated based on linear interpolation. Carbon dioxide exchange was measured with transparent and opaque chambers every 3-4 weeks and the annual net ecosystem exchange (NEE) was modeled according to Drösler (2005). Most of the drained sites were sources of CO2 in both years. NEE increased with lower mean annual water table level. The highest NEE value (1263.5 g CO2-C m-1yr-1) was observed at the driest site of the study; an abandoned fen formerly used for agriculture. In contrast, a former peat extraction site with moist peat and small Pinus sylvestris tress were sinks of CO2 with uptake to 389.6 g CO2-C m-1yr-1. The highest N2O emissions were recorded at a drained agricultural fen with mean annual rates of up to 2347 mg N2O-N m-2 yr-1. Significant fluxes of CH4 (15 g CH4C m-2 h-1) were observed only at the near-natural site in the first year of investigation when precipitation and the mean water

  20. 76 FR 59373 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Generic Annual Catch Limits...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-26

    ...) for Reef Fish Resources, Red Drum, Shrimp, and Coral and Coral Reefs for the Gulf of Mexico (Gulf) for... Coral and Coral Reefs FMP. The majority of harvest of octocorals occurs in waters under the...

  1. Spatial distribution and intra-annual variability of water masses on the Eastern Gulf of Cadiz seabed

    NASA Astrophysics Data System (ADS)

    Bellanco, M. J.; Sánchez-Leal, R. F.

    2016-10-01

    This paper presents the spatial distribution and intra-annual variability of seabed hydrography in the Eastern Gulf of Cadiz based on more than 10 years of near-bottom CTD observations. Well-defined water masses and a variety of mixing products are persistently sorted along three bathymetric areas occupying particular depth intervals: (i) inner shelf waters (<60 m depth), with strong coastal and atmospheric influence; (ii) low-salinity Eastern North Atlantic Central Waters (ENACW), related to the Gulf of Cadiz Current (GCC) along the central and outer shelf (between 100 and 250 m depth); and (iii) a range of salinity and temperature flavors associated with the dense Mediterranean Outflow Water (MOW) occupying the deeper grounds. All three are characterized by significant March-November hydrographic differences suggesting an intra-annual variability pattern. After summer heating and stratification of the water column, warm (17.8 °C) and saline (36.26) waters occupy the inner-shelf in November whereas cooler (14.6 °C) and less saline (36.17) waters occur in March as the combined result of the erosion of the seasonal thermocline and intensified continental runoff. Offshore, colder, more saline and hence denser MOW invades the upper slope in March diluting the easternmost tip of a saltier ENACW wedge and nudging its outer rim up onto the shelf. This narrows and constricts the GCC band in winter, while its bottom trace appears to broaden and stretch eastwards in November. More effective MOW-ENACW mixing west of the Strait of Gibraltar driven both by an elevated MOW and a less stratified ENACW could explain the winter salinification of most of the grounds deeper than 250 m.

  2. Environmental and socioeconomic benefits and limitations of water harvesting techniques in semiarid regions

    NASA Astrophysics Data System (ADS)

    Díaz-Pereira, Elvira; Asunción Romero-Díaz, María; de Vente, Joris

    2016-04-01

    Under climate change, sustainable management of soil and water resources is increasingly important, especially in rainfed agroecosystems of semiarid environments. Water harvesting refers to a range of techniques for the collection and management of flood or rainwater for domestic and agricultural use and for water retention in natural ecosystems. Water harvesting represents a good example of sustainable management of water resources that contribute to water and food security. However, there are often environmental and socioeconomic constraints for implementation of water harvesting techniques, so each condition asks for a specific solution. Here we aim to highlight the environmental and socioeconomic benefits, requirements and limitations of different water harvesting techniques and to characterize their implications for provisioning, regulating, supporting, and cultural ecosystem services. We reviewed 62 water harvesting techniques for semiarid regions extracted from the WOCAT (World Overview of Conservation Approaches and Technologies) database. We discuss aspects related to: i) human and environmental characteristics, ii) cost-benefit ratio during implementation and maintenance phases, iii) socioeconomic and environmental impacts at local and regional scales, and, iv) impacts on ecosystem services. Our review reveals that water harvesting represents very diverse methods of collecting and managing floodwaters and surface runoff. We grouped techniques as 'floodwater harvesting', 'macro-catchment water harvesting', 'micro-catchment water harvesting', and 'rooftop and courtyard' water harvesting. Almost half of all technologies originates from traditional knowledge. The implementation of water harvesting is generally positive on the short-term, to very positive on the long-term, while its maintenance is very positive at short and long-term. However, perception depends on the type of water harvesting and local conditions. Most relevant socioeconomic benefits from

  3. Involvement of the V2 Vasopressin Receptor in Adaptation to Limited Water Supply

    PubMed Central

    Böselt, Iris; Römpler, Holger; Hermsdorf, Thomas; Thor, Doreen; Busch, Wibke; Schulz, Angela; Schöneberg, Torsten

    2009-01-01

    Mammals adapted to a great variety of habitats with different accessibility to water. In addition to changes in kidney morphology, e.g. the length of the loops of Henle, several hormone systems are involved in adaptation to limited water supply, among them the renal-neurohypophysial vasopressin/vasopressin receptor system. Comparison of over 80 mammalian V2 vasopressin receptor (V2R) orthologs revealed high structural and functional conservation of this key component involved in renal water reabsorption. Although many mammalian species have unlimited access to water there is no evidence for complete loss of V2R function indicating an essential role of V2R activity for survival even of those species. In contrast, several marsupial V2R orthologs show a significant increase in basal receptor activity. An increased vasopressin-independent V2R activity can be interpreted as a shift in the set point of the renal-neurohypophysial hormone circuit to realize sufficient water reabsorption already at low hormone levels. As found in other desert mammals arid-adapted marsupials show high urine osmolalities. The gain of basal V2R function in several marsupials may contribute to the increased urine concentration abilities and, therefore, provide an advantage to maintain water and electrolyte homeostasis under limited water supply conditions. PMID:19440390

  4. 10 CFR Appendix B to Part 20 - Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of Radionuclides for...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Concentrations (DACs) of Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for... Concentrations (DACs) of Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for.... Table 2 provides concentration limits for airborne and liquid effluents released to the general...

  5. 10 CFR Appendix B to Part 20 - Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of Radionuclides for...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Concentrations (DACs) of Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for... Concentrations (DACs) of Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for.... Table 2 provides concentration limits for airborne and liquid effluents released to the general...

  6. 10 CFR Appendix B to Part 20 - Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of Radionuclides for...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Concentrations (DACs) of Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for... Concentrations (DACs) of Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for.... Table 2 provides concentration limits for airborne and liquid effluents released to the general...

  7. 10 CFR Appendix B to Part 20 - Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of Radionuclides for...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Concentrations (DACs) of Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for... Concentrations (DACs) of Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for.... Table 2 provides concentration limits for airborne and liquid effluents released to the general...

  8. 10 CFR Appendix B to Part 20 - Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of Radionuclides for...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Concentrations (DACs) of Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for... Concentrations (DACs) of Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for.... Table 2 provides concentration limits for airborne and liquid effluents released to the general...

  9. Water resource data for North Carolina, water year 1993. Volume 1. Surface-water records. Water-data report (Annual), 1 October 1992-30 September 1993

    SciTech Connect

    Barker, R.G.; George, E.D.; Rinehardt, J.F.; Eddins, W.H.

    1994-03-25

    Water resources data for the 1993 water year for North Carolina consist of records of stage, discharge, and water quality of streams; and stage and contents of lakes and reservoirs. The report contains discharge records for 159 gaging stations and stage and contents for 56 lakes and reservoirs; water quality for 54 gaging stations and 5 miscellaneous sites; and continuous daily tide stage for 10 sites. Additional water data were collected at 69 sites not involved in the systematic data-collection program and are published as miscellaneous measurements in the report.

  10. Summary of annual mean and annual harmonic mean statistics of daily mean streamflow for 620 U.S. Geological Survey streamflow-gaging stations in Texas through water year 2007

    USGS Publications Warehouse

    Asquith, William H.; Heitmuller, Franklin T.

    2008-01-01

    Analysts and managers of surface-water resources have interest in annual mean and annual harmonic mean statistics of daily mean streamflow for U.S. Geological Survey (USGS) streamflow-gaging stations in Texas. The mean streamflow represents streamflow volume, whereas the harmonic mean streamflow represents an appropriate statistic for assessing constituent concentrations that might adversely affect human health. In 2008, the USGS, in cooperation with the Texas Commission on Environmental Quality, conducted a large-scale documentation of mean and harmonic mean streamflow for 620 active and inactive, continuous-record, streamflow-gaging stations using period of record data through water year 2007. About 99 stations within the Texas USGS streamflow-gaging network are part of the larger national Hydroclimatic Data Network and are identified. The graphical depictions of annual mean and annual harmonic mean statistics in this report provide a historical perspective of streamflow at each station. Each figure consists of three time-series plots, two flow-duration curves, and a statistical summary of the mean annual and annual harmonic mean streamflow statistics for available data for each station.The first time-series plot depicts daily mean streamflow for the period 1900-2007. Flow-duration curves follow and are a graphical depiction of streamflow variability. Next, the remaining two time-series plots depict annual mean and annual harmonic mean streamflow and are augmented with horizontal lines that depict mean and harmonic mean for the period of record. Monotonic trends for the annual mean streamflow and annual harmonic mean streamflow also are identified using Kendall's tau, and the slope of the trend is depicted using the nonparametric (linear) Theil-Sen line, which is only drawn for p-values less than .10 of tau. The history of annual mean and annual harmonic mean streamflow of one or more streamflow-gaging stations could be used in a watershed, river basin, or other

  11. Effects of water addition on soil arthropods and soil characteristics in a precipitation-limited environment

    NASA Astrophysics Data System (ADS)

    Chikoski, Jennifer M.; Ferguson, Steven H.; Meyer, Lense

    2006-09-01

    We investigated the effect of water addition and season on soil arthropod abundance and soil characteristics (%C, %N, C:N, moisture, pH). The experimental design consisted of 24 groups of five boxes distributed within a small aspen stand in Saskatchewan, Canada. The boxes depressed the soil to create a habitat with suitable microclimate for soil arthropods, and by overturning boxes we counted soil arthropods during weekly surveys from April to September 1999. Soil samples were collected at two-month intervals and water was added once per week to half of the plots. Of the eleven recognizable taxonomic units identified, only mites (Acari) and springtails (Collembola) responded to water addition by increasing abundance, whereas ants decreased in abundance with water addition. During summer, springtail numbers increased with water addition, whereas pH was a stronger determinant of mite abundance. In autumn, springtails were positively correlated with water and negatively correlated with mites, whereas mite abundance was negatively correlated with increasing C:N ratio, positively correlated to water addition, and negatively correlated with springtail abundance. Although both mite and springtail numbers decreased in autumn with a decrease in soil moisture, mites became more abundant than springtails suggesting a predator-prey (mite-springtail) relationship. Water had a significant effect on both springtails and mites in summer and autumn supporting the assertion that prairie soil communities are water limited.

  12. Ballast water regulations and the move toward concentration-based numeric discharge limits.

    PubMed

    Albert, Ryan J; Lishman, John M; Saxena, Juhi R

    2013-03-01

    Ballast water from shipping is a principal source for the introduction of nonindigenous species. As a result, numerous government bodies have adopted various ballast water management practices and discharge standards to slow or eliminate the future introduction and dispersal of these nonindigenous species. For researchers studying ballast water issues, understanding the regulatory framework is helpful to define the scope of research needed by policy makers to develop effective regulations. However, for most scientists, this information is difficult to obtain because it is outside the standard scientific literature and often difficult to interpret. This paper provides a brief review of the regulatory framework directed toward scientists studying ballast water and aquatic invasive species issues. We describe different approaches to ballast water management in international, U.S. federal and state, and domestic ballast water regulation. Specifically, we discuss standards established by the International Maritime Organization (IMO), the U.S. Coast Guard and U.S. Environmental Protection Agency, and individual states in the United States including California, New York, and Minnesota. Additionally, outside the United States, countries such as Australia, Canada, and New Zealand have well-established domestic ballast water regulatory regimes. Different approaches to regulation have recently resulted in variations between numeric concentration-based ballast water discharge limits, particularly in the United States, as well as reliance on use of ballast water exchange pending development and adoption of rigorous science-based discharge standards. To date, numeric concentration-based discharge limits have not generally been based upon a thorough application of risk-assessment methodologies. Regulators, making decisions based on the available information and methodologies before them, have consequently established varying standards, or not established standards at all. The

  13. Comprehensive cooling water study annual report. Volume X: endangered species, Savannah River Plant

    SciTech Connect

    Gladden, J.B.; Lower, M.W.; Mackey, H.E.; Specht, W.L.; Wilde, E.W.

    1985-07-01

    Federally endangered species which occur on the Savannah River Plant (SRP) include the American alligator, red-cockaded woodpecker, the shortnose sturgeon, and the wood stork. Of these species, only the alligator, sturgeon, and wood stork are likely to be affected by the intake or release of cooling water at the SRP. The nearest colony of wood storks to the SRP is the Birdsville Colony, about 40-45 km southwest of potential foraging areas in the SRP Savannah River swamp. In 1983, it contained about six percent of the nesting pairs in the United States and produced about 250 fledglings. Its reproductive success was about the same in 1984. Based on the results of surveys made of foraging areas, both on SRP and offsite in 1983 and 1984, forage fish availability could be reduced by increased water depths in the Steel Creek delta area following L-Reactor restart with once-through cooling. Effluent discharge from SRP facilities probably limits the potential use of the SRP Savannah River swamp by foraging wood storks. The SRP supports a low-to-moderate alligator population. The current information available on the alligators of the SRP suggests that populations in suitable habitats (e.g., Beaver Dam Creek, Steel Creek, and Par Pond) should continue to benefit from the protection provided by the SRP and should remain stable or continue to increase. Based upon information from the literature and fisheries data for the Savannah River, the operations of the SRP do not appear to have adverse effects on the shortnose sturgeon. Based on known life history characteristics, there is no indication that spawning, rearing, or foraging habitats are affected by SRP operations. 64 refs., 20 figs., 12 tabs.

  14. Stability Limit of Water by Metastable Vapor-Liquid Equilibrium with Nanoporous Silicon Membranes.

    PubMed

    Chen, I-Tzu; Sessoms, David A; Sherman, Zachary; Choi, Eugene; Vincent, Olivier; Stroock, Abraham D

    2016-06-16

    Liquid can sustain mechanical tension as its pressure drops below the vapor-liquid coexistence line and becomes less than zero, until it reaches the stability limit-the pressure at which cavitation inevitably occurs. For liquid water, its stability limit is still a subject of debate: the results obtained by researchers using a variety of techniques show discrepancies between the values of the stability limit and its temperature dependence as temperature approaches 0 °C. In this work, we present a study of the stability limit of water by the metastable vapor-liquid equilibrium (MVLE) method with nanoporous silicon membranes. We also report on an experimental system which enables tests of the temperature dependence of the stability limit with MVLE. The stability limit we found increases monotonically (larger tension) as temperature approaches 0 °C; this trend contradicts the centrifugal result of Briggs but agrees with the experiments by acoustic cavitation. This result confirms that a quasi-static method can reach stability values similar to that from the dynamic stretching technique, even close to 0 °C. Nevertheless, our results fall in the range of ∼ -20 to -30 MPa, a range that is consistent with the majority of experiments but is far less negative than the limit obtained in experiments involving quartz inclusions and that predicted for homogeneous nucleation.

  15. The Dynamic of Annual Carbon Allocation to Wood in European Forests Is Consistent with a Combined Source-Sink Limitation of Growth: Implications on Growth Simulations in a Terrestrial Biosphere Model

    NASA Astrophysics Data System (ADS)

    Guillemot, J.; Martin-StPaul, N. K.; Dufrêne, E.; François, C.; Soudani, K.; Ourcival, J. M.; Leadley, P.; Delpierre, N.

    2014-12-01

    The extent to which forest growth is limited by carbon (C) supply (source control) or by cambial activity (sink control) will strongly determines the responses of trees to global changes. However, the physiological processes responsible for the limitation of forest growth are still under debate. The aim of this study was i) to evaluate the key drivers of the annual carbon allocation to wood along large soil and climate regional gradients in four tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex and Picea abies) ii) to implement the identified key drivers in a new C allocation scheme within the CASTANEA terrestrial biosphere model (TBM). Combining field measurements and process-based simulations at 49 sites (931 site-years), our analyses revealed that the inter-site variability in C allocation to wood was predominantly driven by an age-related decline. The direct control of temperature or water stress on sink activity (i.e. independently from their effects on C supply) exerted a strong influence on the annual woody growth in all the species considered, including deciduous temperate species. The lagged effect of the past environment conditions was a significant driver of the annual C allocation to wood. Carbon supply appeared to strongly limit growth only in deciduous temperate species. Our study supports the premise that European forest growth is under a complex panel of source- and sink- limitations, contradicting the simple source control implemented in most TBMs. The implementation of these combined forest growth limitations in the CASTANEA model significantly improved its performance when evaluated against independent stand growth data at the regional scale (mainland France, >103 plots). We finally discuss how the sink imitation affects the CASTANEA simulated projections of forest productivity along the 21th century, especially with respect to the expected fertilizing effect of increasing atmospheric

  16. Annual Forages: Influence on Animal Performance and Water/Nutrient Management

    USDA-ARS?s Scientific Manuscript database

    Annuals can provide short-term grazing between crop rotations or can be interseeded into perennial pastures to increase forage quality and productivity. They provide an opportunity to increase the economic and environmental sustainability of traditional grazing systems. However, to be profitable, an...

  17. Sunflower response to irrigation from limited water supplies with no-till management

    USDA-ARS?s Scientific Manuscript database

    Limited irrigation necessitates maximizing economic returns by rotating crops, so we conducted a field study during 2005-2009 in southwest Kansas to determine the yield response of sunflower to irrigation and evapotranspiration (ETc) and to measure plant growth parameters and soil water use. Sunflow...

  18. Using Computer Models to Explore Alternative Scenarios for Managing Limited Irrigation Water

    USDA-ARS?s Scientific Manuscript database

    Crop water stress due to low precipitation and high temperatures are the main limiting factors for agricultural production in the Great Plains. Corn is grown under either rainfed or irrigated regimes. Irrigation can improve corn profitability in this region, but over-irrigation accelerates depletio...

  19. Challenges of reforestation in a water limited world under climate change

    NASA Astrophysics Data System (ADS)

    Mátyás, Csaba; Sun, Ge

    2014-05-01

    The debate on the ecological benefits of planted forests at the sensitive lower edge of the closed forest belt (at the "xeric limits") is still unresolved. Forests sequester atmospheric carbon dioxide, control water erosion and dust storms, reduce river sedimentation, and mitigate small floods. However, planting trees in areas previously predominantly occupied by grassland or agriculture can dramatically alter the energy and water balance at multiple scales. The forest/grassland transition zone is especially vulnerable to projected drastic temperature and precipitation shifts under future climate change and variability due to its high ecohydrological sensitivity. The study investigates some of the relevant aspects of the ecological and climatic role of plantation forests and potential impacts at the dryland edges of the temperate zone, using case studies from three countries/regions on three continents. We found that, contrary to popular expectations, the effect of forest cover on regional climate might be limited and the influence of reforestation on water resources might turn into negative. Planted forests generally reduce stream flow and lower groundwater table level because of higher water use than previous land cover types. Increased evaporation potential due to global warming and/or extreme drought events likely reduce areas that are appropriate for tree growth and forest establishment. Ecologically conscious forest policy on management, silviculture and reforestation planning requires the consideration of local hydrologic conditions, future climatic conditions, and also of non-forest alternatives of land use. Keywords: drylands, xeric limits, trailing limits, ecohydrology, climate forcing, land use change, forest policy

  20. Addressing water scarcity through limited irrigation cropping: Field experiments and modeling

    USDA-ARS?s Scientific Manuscript database

    Population growth in urbanizing areas such as the Front Range of Colorado has led to increased pressure to transfer water from agriculture to municipalities. In many cases this has led to complete dry up of productive irrigated lands. An option to complete dry-up is the practice of limited or defi...

  1. Annual water storage variability in Southwest Niger: confrontation of absolute gravimetric measurements and magnetic resonance soundings surveys with hydrological observations

    NASA Astrophysics Data System (ADS)

    Pfeffer, J.; Boucher, M.; Hinderer, J.; Favreau, G.; Boy, J.; de Linage, C.; Luck, B.; Oi, M.

    2009-12-01

    Advances in methods of observation are essential to ensure a better understanding of the evolution of water resources considering climate changes and human activities. The GHYRAF (Gravity and Hydrology in Africa) project aims to combine geodetic and gravimetric measurements with dense hydrological surveys to better characterize the annual water storage variability in tropical West Africa. In Southwest Niger periodic absolute gravimetric measurements are performed near a temporary pond where rapid infiltration to the unconfined aquifer occurs. In parallel, pond water level, piezometry, and soil water content are regularly measured. As gravity is sensitive both to local and global variations of water mass distribution, the large scale contribution is first removed using either GRACE satellite data or global hydrology models like GLDAS or ECMWF. The comparison of local water storage variations estimated by gravimetric and hydrological in-situ measurements allows estimating the specific yield of the aquifer to a value ranging between 5 and 7 %. This value is consistent with the 5 to 13 % porosity estimated by Magnetic Resonance Sounding survey. The good agreement between these two independent methods proves the interest in using gravimetric measurements to constrain parameterization of local hydrological modeling. Additional measurements with relative spring gravimeters are scheduled to better characterize spatial heterogeneity in water storage variability.

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

    PubMed

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

    2014-02-01

    Erica arborea (L) is a widespread Mediterranean species, able to cope with water stress and colonize semiarid environments. The eco-physiological plasticity of this species was evaluated by studying plants growing at two sites with different soil moistures on the island of Elba (Italy), through dendrochronological, wood-anatomical analyses and stable isotopes measurements. Intra-annual density fluctuations (IADFs) were abundant in tree rings, and were identified as the key parameter to understand site-specific plant responses to water stress. Our findings showed that the formation of IADFs is mainly related to the high temperature, precipitation patterns and probably to soil water availability, which differs at the selected study sites. The recorded increase in the (13) C-derived intrinsic water use efficiency at the IADFs level was linked to reduced water loss rather than to increasing C assimilation. The variation in vessel size and the different absolute values of δ(18) O among trees growing at the two study sites underlined possible differences in stomatal control of water loss and possible differences in sources of water uptake. This approach not only helped monitor seasonal environmental differences through tree-ring width, but also added valuable information on E. arborea responses to drought and their ecological implications for Mediterranean vegetation dynamics. © 2013 John Wiley & Sons Ltd.

  3. 75 FR 27575 - Agency Information Collection Activities: State Water Resources Research Institute Program Annual...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-17

    ... Geological Survey Agency Information Collection Activities: State Water Resources Research Institute Program... Water Resources Research Act of 1984, as amended (42 U.S.C. 10301 et seq.), authorizes a water resources... report on its activities under the grant. The State Water Resources Research Institute Program issues an...

  4. Parsimonious modeling of vegetation dynamics for ecohydrologic studies of water-limited ecosystems

    NASA Astrophysics Data System (ADS)

    Montaldo, Nicola; Rondena, Roberta; Albertson, John D.; Mancini, Marco

    2005-10-01

    The structure and function of vegetation regulate fluxes across the biosphere-atmosphere interface with large effects in water-limited ecosystems. Vegetation dynamics are often neglected in hydrological modeling except for simple prescriptions of seasonal phenology. However, changes in vegetation densities, influencing the partitioning of incoming solar energy into sensible and latent heat fluxes, can result in long-term changes in both local and global climates with resulting feedbacks on vegetation growth. This paper seeks a simple vegetation dynamics model (VDM) for simulation of the leaf area index (LAI) dynamics in hydrologic models. Five variants of a VDM are employed, with a range of model complexities. The VDMs are coupled to a land surface model (LSM), with the VDM providing the LAI evolution through time and the LSM using this to compute the land surface fluxes and update the soil water contents. We explore the models through case studies of water-limited grass fields in California (United States) and North Carolina (United States). Results show that a simple VDM, simulating only the living aboveground green biomass (i.e., with low parameterization), is able to accurately simulate the LAI. Results also highlight the importance of including the VDM in the LSM when studying the climate-soil-vegetation interactions over moderate to long timescales. The inclusion of the VDM in the LSM is demonstrated to be essential for assessing the impact of interannual rainfall variability on the water budget of a water limited region.

  5. Selected Health Behaviors Moderate the Progression of Functional Limitations in Persons with Multiple Sclerosis: Eleven Years of Annual Follow-Up

    PubMed Central

    Stuifbergen, Alexa K.; Blozis, Shelley; Becker, Heather; Harrison, Tracie; Kullberg, Vicki

    2016-01-01

    Background Multiple sclerosis (MS), a chronic neurological disease typically diagnosed in young adulthood, presents with a wide variety of symptoms, impairments and functional limitations. Given the chronic, unpredictable and long-term nature of this disease, preserving function is essential. Objective The purpose of this study was to identify psychosocial and behavioral factors that might influence the trajectory of functional limitation through eleven years of longitudinal follow-up of a sample of persons with MS. Methods Participants (N=606) completed measures of health behaviors, related constructs and functional limitations annually over eleven years. Longitudinal measures of functional limitations were analyzed using random-effects regression that allows for study of individual differences in the trajectories of a measure. Using the best fitting quadratic growth model, we tested the within and between-person effects of Nutrition, Interpersonal Relationships, Exercise, Stress Management, Health Responsibilities, Spiritual Growth, Self-Rated Health and Barriers, controlling for Age, Year since Diagnosis and Year of Dropout, on Functional Limitations in the 11th year. Results After adjusting for covariates, higher mean scores for Exercise and Self-Rated Health were related to lower levels of Functional Limitations in Year 11. Higher mean scores for Stress Management, Health Responsibilities and Barriers were related to higher levels of Functional Limitations in Year 11. Higher mean Exercise scores and lower mean Health Responsibilities scores were related to slower rates of progression of functional limitations in Year 11. Conclusion Findings suggest that the highly variable trajectory of functional limitations in MS may be extended and shaped through health behavior strategies. PMID:26905974

  6. Stay-green traits to improve wheat adaptation in well-watered and water-limited environments

    PubMed Central

    Christopher, John.T.; Christopher, Mandy J.; Borrell, Andrew K.; Fletcher, Susan; Chenu, Karine

    2016-01-01

    A stay-green phenotype enables crops to retain green leaves longer after anthesis compared with senescent types, potentially improving yield. Measuring the normalized difference vegetative index (NDVI) during the whole senescence period allows quantification of component stay-green traits contributing to a stay-green phenotype. These objective and standardized traits can be compared across genotypes and environments. Traits examined include maximum NDVI near anthesis (Nmax), senescence rate (SR), a trait integrating senescence (SGint), plus time from anthesis to onset (OnS), mid-point (MidS), and near completion (EndS) of senescence. The correlation between stay-green traits and yield was studied in eight contrasting environments ranging from well watered to severely water limited. Environments were each classified into one of the four major drought environment types (ETs) previously identified for the Australian wheat cropping system. SGint, OnS, and MidS tended to have higher values in higher yielding environments for a given genotype, as well as for higher yielding genotypes within a given environment. Correlation between specific stay-green traits and yield varied with ET. In the studied population, SGint, OnS, and MidS strongly correlated with yield in three of the four ETs which included well-watered environments (0.43–0.86), but less so in environments with only moderate water-stress after anthesis (−0.03 to 0.31). In contrast, Nmax was most highly correlated with yield under moderate post-anthesis water stress (0.31–0.43). Selection for particular stay-green traits, combinations of traits, and/or molecular markers associated with the traits could enhance genetic progress toward stay-green wheats with higher, more stable yield in both well-watered and water-limited conditions. PMID:27443279

  7. Stay-green traits to improve wheat adaptation in well-watered and water-limited environments.

    PubMed

    Christopher, John T; Christopher, Mandy J; Borrell, Andrew K; Fletcher, Susan; Chenu, Karine

    2016-09-01

    A stay-green phenotype enables crops to retain green leaves longer after anthesis compared with senescent types, potentially improving yield. Measuring the normalized difference vegetative index (NDVI) during the whole senescence period allows quantification of component stay-green traits contributing to a stay-green phenotype. These objective and standardized traits can be compared across genotypes and environments. Traits examined include maximum NDVI near anthesis (Nmax), senescence rate (SR), a trait integrating senescence (SGint), plus time from anthesis to onset (OnS), mid-point (MidS), and near completion (EndS) of senescence. The correlation between stay-green traits and yield was studied in eight contrasting environments ranging from well watered to severely water limited. Environments were each classified into one of the four major drought environment types (ETs) previously identified for the Australian wheat cropping system. SGint, OnS, and MidS tended to have higher values in higher yielding environments for a given genotype, as well as for higher yielding genotypes within a given environment. Correlation between specific stay-green traits and yield varied with ET. In the studied population, SGint, OnS, and MidS strongly correlated with yield in three of the four ETs which included well-watered environments (0.43-0.86), but less so in environments with only moderate water-stress after anthesis (-0.03 to 0.31). In contrast, Nmax was most highly correlated with yield under moderate post-anthesis water stress (0.31-0.43). Selection for particular stay-green traits, combinations of traits, and/or molecular markers associated with the traits could enhance genetic progress toward stay-green wheats with higher, more stable yield in both well-watered and water-limited conditions. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  8. Solid-state chemistry of photoelectrodes for water photoelectrolysis. Annual report, August 1983-September 1984

    SciTech Connect

    Eror, N.G.

    1984-10-01

    The author previously reported that donor-doped TiO2 and SrTiO3 have different defect structures that seem to be related to their differences in photoresponse. SrTiO3 exhibited bandgap reduction while TiO2 did not. A perovskite analogue, SrZrO3, without variable-valent cations was studied to elucidate the different mechanisms of donor-dopant compensation and photoresponse. The solubility limit of lanthanum was established and the defect structures of both pure and donor-doped SrZrO3 were determined. Electrical conductivity, thermogravimetric, chemical and interdiffusion, and Raman-spectroscopic measurements were used to determine the electronic and ionic defect compensation mechanisms. Both the composition and the crystal structure of heterogeneous catalysts are important in determining their activity, efficiency and specificity. The anatase polymorph of TiO2 is critical for efficient photolysis of water and the irreversible transformation to rutile occurs at relatively modest temperatures. They have used Raman spectroscopy to determine that rutile can be stabilized at temperatures below 450 C. The phase transformation from anatase to rutile was shown to be a function of both impurity type and concentration as well as ambient oxygen activity.

  9. Behavioral responses to annual temperature variation alter the dominant energy pathway, growth, and condition of a cold-water predator.

    PubMed

    Guzzo, Matthew M; Blanchfield, Paul J; Rennie, Michael D

    2017-09-12

    There is a pressing need to understand how ecosystems will respond to climate change. To date, no long-term empirical studies have confirmed that fish populations exhibit adaptive foraging behavior in response to temperature variation and the potential implications this has on fitness. Here, we use an unparalleled 11-y acoustic telemetry, stable isotope, and mark-recapture dataset to test if a population of lake trout (Salvelinus namaycush), a cold-water stenotherm, adjusted its use of habitat and energy sources in response to annual variations in lake temperatures during the open-water season and how these changes translated to the growth and condition of individual fish. We found that climate influenced access to littoral regions in spring (data from telemetry), which in turn influenced energy acquisition (data from isotopes), and growth (mark-recapture data). In more stressful years, those with shorter springs and longer summers, lake trout had reduced access to littoral habitat and assimilated less littoral energy, resulting in reduced growth and condition. Annual variation in prey abundance influenced lake trout foraging tactics (i.e., the balance of the number and duration of forays) but not the overall time spent in littoral regions. Lake trout greatly reduced their use of littoral habitat and occupied deep pelagic waters during the summer. Together, our results provide clear evidence that climate-mediated behavior can influence the dominant energy pathways of top predators, with implications ranging from individual fitness to food web stability.

  10. Behavioral responses to annual temperature variation alter the dominant energy pathway, growth, and condition of a cold-water predator

    PubMed Central

    Blanchfield, Paul J.; Rennie, Michael D.

    2017-01-01

    There is a pressing need to understand how ecosystems will respond to climate change. To date, no long-term empirical studies have confirmed that fish populations exhibit adaptive foraging behavior in response to temperature variation and the potential implications this has on fitness. Here, we use an unparalleled 11-y acoustic telemetry, stable isotope, and mark–recapture dataset to test if a population of lake trout (Salvelinus namaycush), a cold-water stenotherm, adjusted its use of habitat and energy sources in response to annual variations in lake temperatures during the open-water season and how these changes translated to the growth and condition of individual fish. We found that climate influenced access to littoral regions in spring (data from telemetry), which in turn influenced energy acquisition (data from isotopes), and growth (mark–recapture data). In more stressful years, those with shorter springs and longer summers, lake trout had reduced access to littoral habitat and assimilated less littoral energy, resulting in reduced growth and condition. Annual variation in prey abundance influenced lake trout foraging tactics (i.e., the balance of the number and duration of forays) but not the overall time spent in littoral regions. Lake trout greatly reduced their use of littoral habitat and occupied deep pelagic waters during the summer. Together, our results provide clear evidence that climate-mediated behavior can influence the dominant energy pathways of top predators, with implications ranging from individual fitness to food web stability. PMID:28808011

  11. Planning water supply under uncertainty - benefits and limitations of RDM, Info-Gap, economic optimization and many-objective optimization

    NASA Astrophysics Data System (ADS)

    Matrosov, E.; Padula, S.; Huskova, I.; Harou, J. J.

    2012-12-01

    Population growth and the threat of drier or changed climates are likely to increase water scarcity world-wide. A combination of demand management (water conservation) and new supply infrastructure is often needed to meet future projected demands. In this case system planners must decide what to implement, when and at what capacity. Choices can range from infrastructure to policies or a mix of the two, culminating in a complex planning problem. Decision making under uncertainty frameworks can be used to help planners with this planning problem. This presentation introduces, applies and compares four decision making under uncertainty frameworks. The application is to the Thames basin water resource system which includes the city of London. The approaches covered here include least-economic cost capacity expansion optimization (EO), Robust Decision Making (RDM), Info-Gap Decision Theory (Info-gap) and many-objective evolutionary optimization (MOEO). EO searches for the least-economic cost program, i.e. the timing, sizing, and choice of supply-demand management actions/upgrades which meet projected water demands. Instead of striving for optimality, the RDM and Info-gap approaches help build plans that are robust to 'deep' uncertainty in future conditions. The MOEO framework considers multiple performance criteria and uses water systems simulators as a function evaluator for the evolutionary algorithm. Visualizations show Pareto approximate tradeoffs between multiple objectives. In this presentation we detail the application of each framework to the Thames basin (including London) water resource planning problem. Supply and demand options are proposed by the major water companies in the basin. We apply the EO method using a 29 year time horizon and an annual time step considering capital, operating (fixed and variable), social and environmental costs. The method considers all plausible combinations of supply and conservation schemes and capacities proposed by water

  12. A discussion paper on challenges and limitations to water reuse and hygiene in the food industry.

    PubMed

    Casani, Sandra; Rouhany, Mahbod; Knøchel, Susanne

    2005-03-01

    Drinking water is becoming a scarce resource in many areas and both use of water and wastewater outlet are of major ecological and economical importance in many countries. Consumption and discharge may be considerably minimized by means of water reuse. The food industry has a large consumption of water, but until now very limited reuse has taken place due to legislations constraints and hygienic concerns. Legal space for use of water of qualities other than drinking water has been opened with the current legislation. This will, however, in many cases require careful analyses of individual cases based on a thorough understanding of the hazards involved in order to avoid compromising the safety of the food product and thereby the health of consumers. Implementation of water reuse practices in the food industry presents a great challenge for both companies and public health authorities regarding knowledge, technical expertise and documentation. Regulatory, technological, monitoring, verification and ethical aspects associated with microbiologically safe reuse of water in the food industry are discussed and some examples of the challenges ahead and possible approaches are given.

  13. Does water chemistry limit the distribution of New Zealand mud snails in Redwood National Park?

    USGS Publications Warehouse

    Vazquez, Ryan; Ward, Darren M.; Sepulveda, Adam

    2016-01-01

    New Zealand mud snails (NZMS) are exotic mollusks present in many waterways of the western United States. In 2009, NZMS were detected in Redwood Creek in Redwood National Park, CA. Although NZMS are noted for their ability to rapidly increase in abundance and colonize new areas, after more than 5 years in Redwood Creek, their distribution remains limited to a ca. 300 m reach. Recent literature suggests that low specific conductivity and environmental calcium can limit NZMS distribution. We conducted laboratory experiments, exposing NZMS collected from Redwood Creek to both natural waters and artificial treatment solutions, to determine if low conductivity and calcium concentration limit the distribution of NZMS in Redwood National Park. For natural water exposures, we held NZMS in water from their source location (conductivity 135 μS/cm, calcium 13 mg/L) or water from four other locations in the Redwood Creek watershed encompassing a range of conductivity (77–158 μS/cm) and calcium concentration (<5–13 mg/L). For exposures in treatment solutions, we manipulated both conductivity (range 20–200 μS/cm) and calcium concentration (range <5–17.5 mg/L) in a factorial design. Response variables measured included mortality and reproductive output. Adult NZMS survived for long periods (>4 months) in the lowest conductivity waters from Redwood Creek and all but the lowest-conductivity treatment solutions, regardless of calcium concentration. However, reproductive output was very low in all natural waters and all low-calcium treatment solutions. Our results suggest that water chemistry may inhibit the spread of NZMS in Redwood National Park by reducing their reproductive output.

  14. Glycerol enhances fungal germination at the water-activity limit for life.

    PubMed

    Stevenson, Andrew; Hamill, Philip G; Medina, Ángel; Kminek, Gerhard; Rummel, John D; Dijksterhuis, Jan; Timson, David J; Magan, Naresh; Leong, Su-Lin L; Hallsworth, John E

    2017-03-01

    For the most-extreme fungal xerophiles, metabolic activity and cell division typically halts between 0.700 and 0.640 water activity (approximately 70.0-64.0% relative humidity). Here, we investigate whether glycerol can enhance xerophile germination under acute water-activity regimes, using an experimental system which represents the biophysical limit of Earth's biosphere. Spores from a variety of species, including Aspergillus penicillioides, Eurotium halophilicum, Xerochrysium xerophilum (formerly Chrysosporium xerophilum) and Xeromyces bisporus, were produced by cultures growing on media supplemented with glycerol (and contained up to 189 mg glycerol g dry spores(-1) ). The ability of these spores to germinate, and the kinetics of germination, were then determined on a range of media designed to recreate stresses experienced in microbial habitats or anthropogenic systems (with water-activities from 0.765 to 0.575). For A. penicillioides, Eurotium amstelodami, E. halophilicum, X. xerophilum and X. bisporus, germination occurred at lower water-activities than previously recorded (0.640, 0.685, 0.651, 0.664 and 0.637 respectively). In addition, the kinetics of germination at low water-activities were substantially faster than those reported previously. Extrapolations indicated theoretical water-activity minima below these values; as low as 0.570 for A. penicillioides and X. bisporus. Glycerol is present at high concentrations (up to molar levels) in many types of microbial habitat. We discuss the likely role of glycerol in expanding the water-activity limit for microbial cell function in relation to temporal constraints and location of the microbial cell or habitat. The findings reported here have also critical implications for understanding the extremes of Earth's biosphere; for understanding the potency of disease-causing microorganisms; and in biotechnologies that operate at the limits of microbial function. © 2016 The Authors. Environmental Microbiology

  15. National Freshman Attitudes Report, 2011. Special Focus: Attitudes That May Limit Academic Engagement. Sixth Annual National Research Study

    ERIC Educational Resources Information Center

    Noel-Levitz, Inc, 2011

    2011-01-01

    This report describes self-reported attitudes and motivations of first-year college students nationally at the beginning of the undergraduate experience, based on a 100-item motivational assessment administered in the summer and fall of 2010. Highlighted this year are attitudes that may limit academic engagement, suggesting the need for…

  16. 76 FR 82264 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Comprehensive Annual Catch Limit...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-30

    ... Atlantic Region (Snapper- Grouper FMP), the Golden Crab Fishery of the South Atlantic Region, the Dolphin... FMPs for Snapper-Grouper, Dolphin and Wahoo, Golden Crab, and Sargassum; revise the snapper-grouper... dolphin from for-hire vessels; and set a minimum size limit for dolphin off most of the South...

  17. Annual water-resources review, White Sands Missile Range, 1976: a basic-data report

    USGS Publications Warehouse

    Cruz, R.R.

    1977-01-01

    Information is presented on the water resources of the White Sands Missile Range, N. Mex., that was collected during the period December 1975 to December 1976 by personnel of the U.S. Geological Survey, Water Resources Division. Data on ground-water pumpage and resulting water-level fluctuation, chemical quality and precipitation, and miscellaneous items of interest are summarized. Water-level observations were made in 63 borehole, supply, test, and observation wells on the Range. Water samples were collected and analyzed for chemical quality from 8 test wells. (Woodard-USGS)

  18. Water Budget Managers Report to Northwest Power Planning Council, 1986 Annual Report.

    SciTech Connect

    Karr, Malcolm; DeHart, Michele

    1986-12-01

    In addition to management of the Water Budget, the Water Budget Managers and FPC staff developed and directed the Smolt Monitoring and Water Budget Evaluation Programs of Section 304(d) of the Fish and Wildlife Program. The fishery agencies and tribes also authorized the Water Budget Managers to coordinate agency and tribal system operational requests throughout the year, including spill management for fish passage. This report summarizes Water Budget Manager activities in implementing program measures, including 1986 flow conditions, water budget usage and spill management, and the in-season management portion of the 1986 Smolt Monitoring Program including data management.

  19. Fiscal year 1987 program report (Massachusetts Water Resources Research Center). Annual report

    SciTech Connect

    Godfrey, P.J.

    1988-12-01

    The 1987-88 Massachusetts WRRC program (Federal FY87) focused on areas of high priority for the state and region: acid-deposition impacts, minimization of nitrate ground-water contamination, drinking water pricing, and proposed water diversion from a 'Wild and Scenic' river. The Water Resources Institute Program (WRIP) projects studied central Massachusetts cloud and fog acidity, peat use in rural sewage systems to minimize nitrate ground-water contamination, and determination of true water costs to help plan new sources or infrastructure renovation.

  20. Water Quality Trends in the Entiat River Subbasin: Final Annual Report to BPA and NOAA Fisheries, 2008.

    SciTech Connect

    Woodsmith, Richard; Bookter, Andy

    2008-03-11

    The Integrated Status and Effectiveness Monitoring Project (ISEMP) program monitors the status and trend of water quality elements that may affect restoration project effectiveness in the Entiat subbasin. As part of this effort, the PNW Research Station (PNW) measures, analyzes and interprets temporal trends in natural stream water pH, dissolved oxygen, specific conductance and temperature. The Entiat River is currently on the Clean Water Act 303(d) list for pH exceedence, and there is insufficient information to determine the spatial and temporal extent or potential causes of this exceedence. In the late spring 2007, PNW deployed data-logging, multiparameter probes at four locations in the Entiat subbasin to measure water quality parameters, focusing on pH. Data collection was seasonally interrupted by river ice in early December. Daily average pH did not exceed the water quality standard of 8.5 at any of the measurements sites. However, instantaneous values did exceed this standard near the mouth of the Entiat River during late summer-fall period. This suggested that in the lowest portion of the river peaks in pH may be occurring because of photosynthesis caused by high rates of periphyton productivity in response to increased sunlight, temperature, and possible nutrient enrichment. Conversely, dissolved oxygen reached annual low levels during this same late summer-fall period, in part because of increased water temperatures and increased biochemical oxygen demand.

  1. The Climate change impact on the water balance and use efficiency of two contrasting water limited Mediterranean ecosystems in Sardinia

    NASA Astrophysics Data System (ADS)

    Montaldo, Nicola; Corona, Roberto; Albertson, John

    2016-04-01

    Mediterranean ecosystems are commonly heterogeneous savanna-like ecosystems, with contrasting plant functional types (PFT) competing for the water use. Often deforestation activities have been more intensive along the plan and alluvial river valleys, where deep soils are well suited for agricultural and grass became the primary PFT, while more natural woody vegetation (trees and shrubs) survived in the steep hillslopes and mountain areas, where soil thickness is low, i.e. less attractive for agricultural. Hence, Mediterranean regions are characterized by two main ecosystems, grassland and woodland, which for both natural and anthropogenic causes can grow in soils with also different characteristics (texture, hydraulic properties, depth), highly impacting water resources. Mediterranean regions suffer water scarcity produced in part by natural (e.g., climate variations) influences. For instance, in the Flumendosa basin water reservoir system, which plays a primary role in the water supply for much of southern Sardinia, the average annual input from stream discharge in the latter part of the 20th century was less than half the historic average rate. The precipitation over the Flumendosa basin has decreased, but not at such a drastic rate as the discharge, suggesting a marked non-linear response of discharge to precipitation changes. Indeed, precipitation decreased in winter months, which are crucial for reservoirs recharge through runoff. At the same time air temperature increased during the spring-summer season, when the precipitation slightly increased. The IPCC models predicts a further increase of drought in the Mediterranean region during winter, increasing the uncertainty on the future of the water resources system of these regions. Hence, there is the need to investigate the role of the PFT vegetation dynamics on the soil water budget of these ecosystems in the context of the climate change, and predict hydrologic variables for climate change scenarios

  2. Water Budget Managers Report to Northwest Power Planning Council, 1985 Annual Report.

    SciTech Connect

    Karr, Malcolm H., Maher, Mark

    1985-11-01

    1985 was the third year of operation of the Water Budget Center under the guidance and supervision of the fishery agencies and tribal Water Budget Managers, and the second year of formal water budget implementation. The Water Budget Managers also directed the Smolt Monitoring and Water Budget Evaluation Programs of Section 304(d) of the Fish and wildlife Program. The Water Budget Managers work to implement policies and priorities of the state and federal fishery agencies and Indian tribes in carrying out applicable measures of the Fish and Wildlife Program. This report summarizes Water Budget Manager activities in implementing program measures, including 1985 flow conditions, water budget usage and spill management and problems encountered, and the 1985 Smolt Monitoring Program and preliminary results. Recommendations are included.

  3. Annual Report Card Shows Water Quality Improvements in Parts of the Mystic River Watershed

    EPA Pesticide Factsheets

    Each year, the US Environmental Protection Agency (EPA), in collaboration with the Mystic River Watershed Association (MyRWA), issues a Water Quality Report Card on water quality in the Mystic River watershed.

  4. Climatic correlates of tree mortality in water- and energy-limited forests

    USGS Publications Warehouse

    Das, Adrian J.; Stephenson, Nathan L.; Flint, Alan; Das, Tapash; van Mantgem, Phillip J.

    2013-01-01

    Recent increases in tree mortality rates across the western USA are correlated with increasing temperatures, but mechanisms remain unresolved. Specifically, increasing mortality could predominantly be a consequence of temperature-induced increases in either (1) drought stress, or (2) the effectiveness of tree-killing insects and pathogens. Using long-term data from California’s Sierra Nevada mountain range, we found that in water-limited (low-elevation) forests mortality was unambiguously best modeled by climatic water deficit, consistent with the first mechanism. In energy-limited (high-elevation) forests deficit models were only equivocally better than temperature models, suggesting that the second mechanism is increasingly important in these forests. We could not distinguish between models predicting mortality using absolute versus relative changes in water deficit, and these two model types led to different forecasts of mortality vulnerability under future climate scenarios. Our results provide evidence for differing climatic controls of tree mortality in water- and energy-limited forests, while highlighting the need for an improved understanding of tree mortality processes.

  5. Climatic correlates of tree mortality in water- and energy-limited forests.

    PubMed

    Das, Adrian J; Stephenson, Nathan L; Flint, Alan; Das, Tapash; van Mantgem, Phillip J

    2013-01-01

    Recent increases in tree mortality rates across the western USA are correlated with increasing temperatures, but mechanisms remain unresolved. Specifically, increasing mortality could predominantly be a consequence of temperature-induced increases in either (1) drought stress, or (2) the effectiveness of tree-killing insects and pathogens. Using long-term data from California's Sierra Nevada mountain range, we found that in water-limited (low-elevation) forests mortality was unambiguously best modeled by climatic water deficit, consistent with the first mechanism. In energy-limited (high-elevation) forests deficit models were only equivocally better than temperature models, suggesting that the second mechanism is increasingly important in these forests. We could not distinguish between models predicting mortality using absolute versus relative changes in water deficit, and these two model types led to different forecasts of mortality vulnerability under future climate scenarios. Our results provide evidence for differing climatic controls of tree mortality in water- and energy-limited forests, while highlighting the need for an improved understanding of tree mortality processes.

  6. Contrasting water strategies of two Mediterranean shrubs of limited distribution: uncertain future under a drier climate.

    PubMed

    Lázaro-Nogal, Ana; Forner, Alicia; Traveset, Anna; Valladares, Fernando

    2013-12-01

    Plants have evolved different strategies to cope with drought, involving alternative ecophysiologies and different levels of plasticity. These strategies are critical for species of limited distribution, which are especially vulnerable to the current rates of rapid environmental change. The aim of this study was to assess the water strategy of two species with limited distribution, Cneorum tricoccon L. and Rhamnus ludovici-salvatoris Chodat., and evaluate their interpopulation variability along an aridity gradient to estimate their vulnerability to a drier climate. We measured different ecophysiological traits influenced by drought--stomatal conductance, maximum photochemical efficiency of photosynthesis II, carbon isotope ratio and chlorophyll concentration--in two climatically contrasting years, before and during summer drought. Both species were vulnerable to drought at the aridity limit of the gradient, but showed contrasting water strategies: while C. tricoccon was consistent in its water conservation strategy across the aridity gradient, R. ludovici-salvatoris was not, displaying higher and more variable stomatal conductances and being able to increase water-use efficiency at the most xeric sites. Changes in length and intensity of drought events may favor one species' strategy to the detriment of the other: C. tricoccon is more vulnerable to chronic and prolonged droughts, whereas short but acute droughts might have a stronger effect on R. ludovici-salvatoris. In those communities where these two species coexist, such different strategies might lead to changes in community structure under climate change scenarios, with unknown cascade effects on ecosystem functioning.

  7. Contribution of water-limited ecoregions to their own supply of rainfall

    NASA Astrophysics Data System (ADS)

    Miralles, Diego G.; Nieto, Raquel; McDowell, Nathan G.; Dorigo, Wouter A.; Verhoest, Niko EC; Liu, Yi Y.; Teuling, Adriaan J.; Dolman, A. Johannes; Good, Stephen P.; Gimeno, Luis

    2016-12-01

    The occurrence of wet and dry growing seasons in water-limited regions remains poorly understood, partly due to the complex role that these regions play in the genesis of their own rainfall. This limits the predictability of global carbon and water budgets, and hinders the regional management of natural resources. Using novel satellite observations and atmospheric trajectory modelling, we unravel the origin and immediate drivers of growing-season precipitation, and the extent to which ecoregions themselves contribute to their own supply of rainfall. Results show that persistent anomalies in growing-season precipitation—and subsequent biomass anomalies—are caused by a complex interplay of land and ocean evaporation, air circulation and local atmospheric stability changes. For regions such as the Kalahari and Australia, the volumes of moisture recycling decline in dry years, providing a positive feedback that intensifies dry conditions. However, recycling ratios increase up to 40%, pointing to the crucial role of these regions in generating their own supply of rainfall; transpiration in periods of water stress allows vegetation to partly offset the decrease in regional precipitation. Findings highlight the need to adequately represent vegetation-atmosphere feedbacks in models to predict biomass changes and to simulate the fate of water-limited regions in our warming climate.

  8. Climatic Correlates of Tree Mortality in Water- and Energy-Limited Forests

    PubMed Central

    Das, Adrian J.; Stephenson, Nathan L.; Flint, Alan; Das, Tapash; van Mantgem, Phillip J.

    2013-01-01

    Recent increases in tree mortality rates across the western USA are correlated with increasing temperatures, but mechanisms remain unresolved. Specifically, increasing mortality could predominantly be a consequence of temperature-induced increases in either (1) drought stress, or (2) the effectiveness of tree-killing insects and pathogens. Using long-term data from California’s Sierra Nevada mountain range, we found that in water-limited (low-elevation) forests mortality was unambiguously best modeled by climatic water deficit, consistent with the first mechanism. In energy-limited (high-elevation) forests deficit models were only equivocally better than temperature models, suggesting that the second mechanism is increasingly important in these forests. We could not distinguish between models predicting mortality using absolute versus relative changes in water deficit, and these two model types led to different forecasts of mortality vulnerability under future climate scenarios. Our results provide evidence for differing climatic controls of tree mortality in water- and energy-limited forests, while highlighting the need for an improved understanding of tree mortality processes. PMID:23936118

  9. Stocking of Offsite Waters for Hungry Horse Dam Mitigation; Creston National Fish Hatchery, 2001-2002 Annual Report.

    SciTech Connect

    Maskill, Mark

    2003-03-01

    Mitigation Objective 1: Produce Native Westslope Cutthroat Trout at Creston NFH--Task: Acquire eggs and rear up to 100,000 Westslope Cutthroat trout annually for offsite mitigation stocking. Accomplishments: A total of 150,000 westslope cutthroat eggs (M012 strain) were acquired from the State of Montana Washoe Park State Fish Hatchery in July 2001 for this objective. Another 120,000 westslope cutthroat eggs were taken from feral fish at Rogers Lake in May of 2001 by the Creston Hatchery crew. The fish were reared using approved fish culture techniques as defined in the U.S. Department of the Interior Fish Hatchery Management guidelines. Post release survival and angler success is monitored annually by Montana Fish Wildlife and Parks (MFWP) and the Confederated Salish and Kootenai Tribe (CSKT). Stocking numbers and locations may vary yearly based on results of biological monitoring. Mitigation Objective 2: Produce Rainbow Trout at Creston NFH--Task: Acquire and rear up to 100,000 Rainbow trout annually for offsite mitigation in closed basin waters. Accomplishments: A total of 50,500 rainbow trout eggs (Arlee strain) were acquired from the State of Montana Arlee State Fish Hatchery in December 2001 for this objective. The fish were reared using approved fish culture techniques as defined in the U.S. Department of the Interior Fish Hatchery Management guidelines. Arlee rainbow trout are being used for this objective because the stocking locations are terminal basin reservoirs and habitat conditions and returns to creel are unsuitable for native cutthroat. Post release survival and angler success is monitored annually by the Confederated Salish and Kootenai Tribe (CSKT). Stocking numbers and locations may vary yearly based on results of biological monitoring.

  10. Annual summary of ground-water conditions in Arizona, spring 1979 to spring 1980

    USGS Publications Warehouse

    ,

    1981-01-01

    Withdrawal of ground water, about 4.0 million acre-feet in Arizona in 1979, is about 200,000 acre-feet less than the amount withdrawn in 1978. The withdrawals in 1978 and 1979 are the smallest since the mid-1950 's except in 1966. Nearly all the decrease was in the amount of ground water used for irrigation in the Basin and Range lowlands province. The large amount of water in storage in the surface-water reservoirs, release of water from the reservoirs, floods, and conservation practices contributed to the decrease in ground-water use and caused water-level rises in the Salt River Valley, Gila Bend basin, and Gila River drainage from Painted Rock Dam to Texas Hill. Two small-scale maps show ground-water pumpage by areas and the status of the ground-water inventory in the State. The main map, which is at a scale of 1:500,000, shows potential well production, depth to water in selected wells in spring 1980, and change in water level in selected wells from 1975 to 1980. A brief text summarizes the current ground-water conditions in the State. (USGS)

  11. Modeling analysis of ground water recharge potential on alluvial fans using limited data.

    PubMed

    Munévar, A; Mariño, M A

    1999-01-01

    A modeling approach is developed to evaluate the potential for artificial recharge on alluvial fans in the Salinas Valley, California, using limited data of soil texture, soil hydraulic properties, and interwell stratigraphy. Promising areas for surface recharge are identified and mapped on a broad-scale using soil surveys, geologic investigations, permeability tests, and seasonal ground water response to rainfall and runoff. Two-dimensional representations of the vadose zone at selected sites are then constructed from drillers'logs and soil material types are estimated. Next, hydraulic properties are assigned to each soil material type by comparing them to laboratory-tested cores of similar soils taken from one site. Finally, water flow through the vadose zone is modeled in two dimensions at seven sites using a transient, finite-difference, variably saturated flow model. Average infiltration rates range from 0.84 to 1.54 cm/hr and recharge efficiency, the percentage of infiltrated water that reaches the water table, varies from 51% to 79%. Infiltration rates and recharge efficiency are found to be relatively insensitive to recharge basin ponding depth due to the thickness of the vadose zones modeled (31 to 84 m). The impact of artificial recharge on the Salinas Valley ground water basin is investigated by simulating the regional ground water response to surface spreading and streamflow augmentation with a recently calibrated, finite-element, ground water-surface water model for the basin. It was determined that a combined approach of surface recharge and streamflow augmentation significantly reduces the state of ground water overdraft and, to a lesser extent, reduces the rate of sea water intrusion.

  12. Increasing demands on limited water resources: Consequences for two endangered plants in Amargosa Valley, USA.

    PubMed

    Hasselquist, Niles J; Allen, Michael F

    2009-03-01

    Recent population expansion throughout the Southwest United States has created an unprecedented demand for already limited water resources, which may have severe consequences on the persistence of some species. Two such species are the federally protected Nitrophila mohavensis (Chenopodiaceae) and Grindelia fraxino-pratensis (Asteraceae) found in Amargosa Valley, one valley east of Death Valley, California. Because both species are federally protected, no plant material could be harvested for analysis. We therefore used a chamber system to collect transpired water for isotopic analysis. After a correction for isotopic enrichment during transpiration, δ(18)O values of plant xylem water were significantly different between N. mohavensis and G. fraxino-pratensis throughout the study. Using a multisource mixing model, we found that both N. mohavensis and G. fraxino-pratensis used soil moisture near the soil surface in early spring when surface water was present. However, during the dry summer months, G. fraxino-pratensis tracked soil moisture to deeper depths, whereas N. mohavensis continued to use soil moisture near the soil surface. These results indicate that pumping groundwater and subsequently lowering the water table may directly prevent G. fraxino-pratensis from accessing water, whereas these same conditions may indirectly affect N. mohavensis by reducing surface soil moisture and thus its ability to access water.

  13. Dispersal Limitations on Fish Community Recovery Following Long-term Water Quality Remediation

    SciTech Connect

    McManamay, Ryan A.; Jett, Robert T.; Ryon, Michael G.; Gregory, Scott M.; Stratton, Sally H.; Peterson, Mark J.

    2016-02-22

    Holistic restoration approaches, such as water quality remediation, are likely to meet conservation objectives because they are typically implemented at watershed scales, as opposed to individual stream reaches. However, habitat fragmentation may impose constraints on the ecological effectiveness of holistic restoration strategies by limiting colonization following remediation. We questioned the importance of dispersal limitations to fish community recovery following long-term water quality remediation and species reintroductions across the White Oak Creek (WOC) watershed near Oak Ridge, Tennessee (USA). Long-term (26 years) responses in fish species richness and biomass to water quality remediation were evaluated in light of habitat fragmentation and population isolation from instream barriers, which varied in their passage potential. In addition, ordination techniques were used to determine the relative importance of habitat connectivity and water quality, in explaining variation fish communities relative to environmental fluctuations, i.e. streamflow. Ecological recovery (changes in richness) at each site was negatively related to barrier index, a measure of community isolation by barriers relative to stream distance. Following species reintroductions, dispersal by fish species was consistently in the downstream direction and upstream passage above barriers was non-existent. The importance of barrier index in explaining variation in fish communities was stronger during higher flow conditions, but decreased over time an indication of increasing community stability and loss of seasonal migrants. Compared to habitat fragmentation, existing water quality concerns (i.e., outfalls, point source discharges) were unrelated to ecological recovery, but explained relatively high variation in community dynamics. Our results suggest that habitat fragmentation limited the ecological effectiveness of intensive water quality remediation efforts and fish reintroduction efforts

  14. Dispersal Limitations on Fish Community Recovery Following Long-term Water Quality Remediation

    DOE PAGES

    McManamay, Ryan A.; Jett, Robert T.; Ryon, Michael G.; ...

    2016-02-22

    Holistic restoration approaches, such as water quality remediation, are likely to meet conservation objectives because they are typically implemented at watershed scales, as opposed to individual stream reaches. However, habitat fragmentation may impose constraints on the ecological effectiveness of holistic restoration strategies by limiting colonization following remediation. We questioned the importance of dispersal limitations to fish community recovery following long-term water quality remediation and species reintroductions across the White Oak Creek (WOC) watershed near Oak Ridge, Tennessee (USA). Long-term (26 years) responses in fish species richness and biomass to water quality remediation were evaluated in light of habitat fragmentation andmore » population isolation from instream barriers, which varied in their passage potential. In addition, ordination techniques were used to determine the relative importance of habitat connectivity and water quality, in explaining variation fish communities relative to environmental fluctuations, i.e. streamflow. Ecological recovery (changes in richness) at each site was negatively related to barrier index, a measure of community isolation by barriers relative to stream distance. Following species reintroductions, dispersal by fish species was consistently in the downstream direction and upstream passage above barriers was non-existent. The importance of barrier index in explaining variation in fish communities was stronger during higher flow conditions, but decreased over time an indication of increasing community stability and loss of seasonal migrants. Compared to habitat fragmentation, existing water quality concerns (i.e., outfalls, point source discharges) were unrelated to ecological recovery, but explained relatively high variation in community dynamics. Our results suggest that habitat fragmentation limited the ecological effectiveness of intensive water quality remediation efforts and fish reintroduction

  15. The need for a reassessment of the safe upper limit of selenium in drinking water.

    PubMed

    Vinceti, Marco; Crespi, Catherine M; Bonvicini, Francesca; Malagoli, Carlotta; Ferrante, Margherita; Marmiroli, Sandra; Stranges, Saverio

    2013-01-15

    Results of recent epidemiologic studies suggest the need to reassess the safe upper limit in drinking water of selenium, a metalloid with both toxicological and nutritional properties. Observational and experimental human studies on health effects of organic selenium compounds consumed through diet or supplements, and of inorganic selenium consumed through drinking water, have shown that human toxicity may occur at much lower levels than previously surmised. Evidence indicates that the chemical form of selenium strongly influences its toxicity, and that its biological activity may differ in different species, emphasizing the importance of the few human studies on health effects of the specific selenium compounds found in drinking water. Epidemiologic studies that investigated the effects of selenate, an inorganic selenium species commonly found in drinking water, together with evidence of toxicity of inorganic selenium at low levels in from in vitro and animal studies, indicate that health risks may occur at exposures below the current European Union and World Health Organization upper limit and guideline of 10 and 40 μg/l, respectively, and suggest reduction to 1 μg/l in order to adequately protect human health. Although few drinking waters are currently known to have selenium concentrations exceeding this level, the public health importance of this issue should not be overlooked, and further epidemiologic research is critically needed in this area. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Plant transpiration and groundwater dynamics in water-limited climates: Impacts of hydraulic redistribution

    NASA Astrophysics Data System (ADS)

    Luo, Xiangyu; Liang, Xu; Lin, Jeen-Shang

    2016-06-01

    The role of groundwater in sustaining plant transpiration constitutes an important but not well-understood aspect of the interactions between groundwater, vegetation, the land surface, and the atmosphere. The effect of the hydraulic redistribution (HR) process by plant roots on the interplay between plant transpiration and groundwater dynamics under water-limited climates is investigated by using the Variable Infiltration Capacity Plus (VIC+) land surface model. Numerical experiments, with or without explicitly considering HR, are conducted on soil columns over a range of groundwater table depths (GWTDs) under different vegetative land covers, soil types, and precipitation conditions. When HR is not included, this study obtains transpiration-GWTD relationships consistent with those from watershed studies that do not include HR. When HR is included, the transpiration-GWTD relationships are modified. The modification introduced by HR is manifested in the soil moisture of the root zone. The mechanism of HR is explained by detailing the roles of the hydraulically redistributed water, the upward diffusion of soil water, and the daytime root uptake. We have found that HR is particularly important in water-limited climates under which plants have high transpiration demand. At the beginning stage of a dry period, HR modulates the severe impacts that climate has on plant transpiration. Only after a prolonged dry period, impacts of HR are lessened when the groundwater table drops below the depth of water uptake by roots and are diminished when plant transpiration is decoupled from groundwater dynamics.

  17. Physiological strategies of co-occurring oaks in a water- and nutrient-limited ecosystem.

    PubMed

    Renninger, Heidi J; Carlo, Nicholas; Clark, Kenneth L; Schäfer, Karina V R

    2014-02-01

    Oak species are well suited to water-limited conditions by either avoiding water stress through deep rooting or tolerating water stress through tight stomatal control. In co-occurring species where resources are limited, species may either partition resources in space and/or time or exhibit differing efficiencies in the use of limited resources. Therefore, this study seeks to determine whether two co-occurring oak species (Quercus prinus L. and Quercus velutina Lam.) differ in physiological parameters including photosynthesis, stomatal conductance, water-use (WUE) and nitrogen-use efficiency (NUE), as well as to characterize transpiration and average canopy stomatal responses to climatic variables in a sandy, well-drained and nutrient-limited ecosystem. The study was conducted in the New Jersey Pinelands and we measured sap flux over a 3-year period, as well as leaf gas exchange, leaf nitrogen and carbon isotope concentrations. Both oak species showed relatively steep increases in leaf-specific transpiration at low vapor pressure deficit (VPD) values before maximum transpiration rates were achieved, which were sustained over a broad range in VPD. This suggests tight stomatal control over transpiration in both species, although Q. velutina showed significantly higher leaf-level and canopy-level stomatal conductance than Q. prinus. Average daytime stomatal conductance was positively correlated with soil moisture and both oak species maintained at least 75% of their maximum canopy stomatal conductance at soil moistures in the upper soil layer (0-0.3 m) as low as 0.03 m(3) m(3)(-3). Quercus velutina had significantly higher photosynthetic rates, maximum Rubisco-limited and electron-transport-limited carboxylation rates, dark respiration rates and nitrogen concentration per unit leaf area than Q. prinus. However, both species exhibited similar WUEs and NUEs. Therefore, Q. prinus has a more conservative resource-use strategy, while Q. velutina may need to exploit niches

  18. Annual water-level measurements in observation wells, 1951-1955, and atlas of maps showing changes in water levels for various periods from beginning of record through 1954, New Mexico

    USGS Publications Warehouse

    Reeder, Harold O.

    1959-01-01

    This report tabulates the annual measurements of water level in the observation wells in the various irrigated areas, primarily from 1951 through 1955. It summarizes changes in water level by discussion and with an atlas of nearly all the maps of change of water level for the period of record to 1955 for each area in which observations are being made. Included also are hydrographs for the period of record through 1954 of several selected wells in the various areas irrigated from ground-water sources. The annual measurements of water level before 1951, seasonal measurements, and daily records of water levels in wells equipped with recording gages have been published in an annual series of U. S. Geological Survey water-supply papers.

  19. Annual water-resources review White Sands Missile Range, New Mexico

    USGS Publications Warehouse

    Cruz, R.R.

    1980-01-01

    Ground-water data were collected in 1979 at White Sands Missile Range in south-central New Mexico. Total ground-water pumpage from the Post Headquarters well field, which produces more than 98% of the water used at White Sands Missile Range, was 1.4 million gallons more in 1979 than in 1978. The most significant seasonal water-level declines observed in 1979 were in supply well 22 (36.35 feet) and test well T-7 (15.98 feet). The chemical quality of water samples collected in 1979 was similar to that collected at comparable depths and periods in 1978. (USGS)

  20. Annual water-resources review, White Sands Missile Range, New Mexico, 1978

    USGS Publications Warehouse

    Cruz, R.R.

    1979-01-01

    Ground-water data were collected in 1978 at White Sands Missile Range in south-central New Mexico. Total ground-water pumpage in 1978 was 692,045,700 gallons or 7,248,300 less than in 1977. Wells at the Post Headquarters produced 98 percent of the total volume. Water levels in test wells around the Post Headquarters well field show seasonal declines ranging from 14.78 feet to 0.71 feet. The water samples collected from the supply wells show that the chemical quality of the water is slightly better during the period of greatest declines. (Woodard-USGS)

  1. Stoichiometry, Metabolism and Nutrient Limitation Across the Periodic Table in Natural Flowing-Water Chemostats

    NASA Astrophysics Data System (ADS)

    Cohen, M. J.; Nifong, R. L.; Kurz, M. J.; Cropper, W. P.; Martin, J. B.

    2014-12-01

    Relative supplies of macro and micronutrients (C,N,P, various metals), along with light and water, controls ecosystem metabolism, trophic energy transfer and community structure. Here we test the hypothesis, using measurements from 41 spring-fed rivers in Florida, that tissue stoichiometry indicates autotroph nutrient limitation status. Low variation in discharge, temperature and chemical composition within springs, but large variation across springs creates an ideal setting to assess the relationship between limitation and resource supply. Molar N:P ranges from 0.4 to 90, subjecting autotrophs to dramatically different nutrient supply. Over this gradient, species-specific autotroph tissue C:N:P ratios are strictly homeostatic, and with no evidence that nutrient supply affects species composition. Expanding to include 19 metals and micronutrients revealed autotrophs are more plastic in response to micronutrient variation, particularly for iron and manganese whose supply fluxes are small compared to biotic demand. Using a Droop model modified to reflect springs conditions (benthic production, light limitation, high hydraulic turnover), we show that tissue stoichiometry transitions from homeostatic to plastic with the onset of nutrient limitation, providing a potentially powerful new tool for predicting nutrient limitation and thus eutrophication in flowing waters.

  2. UK catchment nutrient loads 1993-2003, a new approach using harmonised monitoring scheme data: temporal changes, geographical distribution, limiting nutrients and loads to coastal waters.

    PubMed

    Earl, Timothy J; Upton, Graham J G; Nedwell, David B

    2014-07-01

    The work provides robust estimates of nutrient loads (nitrate and phosphate) from all UK catchments: as required by the Water Framework Directive to monitor catchments' health, and to inform management of these environments. To calculate nutrient loads, data for nutrient concentrations and water flow are combined. In the UK, flow data are typically available at hourly intervals at more than 1300 gauging stations but concentration data are collected less frequently (roughly weekly) and at fewer locations (about 280). The sparseness of the concentration data limits the occasions for which load can be calculated, so a mathematical model was derived which was used to interpolate the concentrations between measurements. The model's parameters provide useful information about the annual nutrient concentration cycles within any catchment, and permitted improved estimates of both the annual loads of N and P, and of the N : P ratios, from mainland UK catchments. Data from 1993-2003 showed nitrate loads from UK catchments were generally constant, while orthophosphate loads generally declined. N : P ratios suggested that most catchments in the north and west of the UK were potentially P-limited although a few were potentially N-limited, while many in central and eastern UK oscillated seasonally between N and P limitation. Knowledge of the nutrient which is potentially limiting to biological productivity is a key factor for management of a catchment's nutrient loads. Calculations of nutrient export loads to coastal regions showed that UK catchments contributed only about 16.5% of total fluvial loads of nitrate to the North Sea, or about 3% of the total N loads when inputs from the Atlantic were included. Orthophosphate loads from the UK catchments into the North Sea were only 1.7% of the total P inputs from rivers and the Atlantic but did not include riverine inputs of P adsorbed to particles.

  3. 2014 annual summary of the lower Gunnison River Basin Selenium Management Program water-quality monitoring, Colorado

    USGS Publications Warehouse

    Henneberg, Mark F.

    2016-08-10

    Dissolved-selenium loading analyses of data collected at 18 water-quality sites in the lower Gunnison River Basin in Colorado were completed through water year (WY) 2014. A WY is defined as October 1–September 30. Selenium is a trace element that bioaccumulates in aquatic food chains and can cause reproductive failure, deformities, and other harmful effects. This report presents information on the dissolved-selenium loads at 18 sites in the lower Gunnison River Basin for WYs 2011–2014. Annual dissolved-selenium loads were calculated at 5 sites with continuous U.S. Geological Survey (USGS) streamflow gages, whereas instantaneous dissolved-selenium loads were calculated for the remaining 13 sites using water-quality samples that had been collected periodically during WYs 2011–2014. Annual dissolved-selenium loads for WY 2014 ranged from 336 pounds (lb) at Uncompahgre River at Colona to 13,300 lb at Gunnison River near Grand Junction (Whitewater). Most sites in the basin had a median instantaneous dissolved-selenium load of less than 20.0 lb per day. In general, dissolved-selenium loads at Gunnison River main-stem sites showed an increase from upstream to downstream.The State of Colorado water-quality standard for dissolved selenium of 4.6 micrograms per liter (µg/L) was compared to the 85th percentiles for dissolved selenium at selected water-quality sites. Annual 85th percentiles for dissolved selenium were calculated for the five core USGS sites having streamflow gages using estimated dissolved-selenium concentrations from linear regression models. These annual 85th percentiles in WY 2014 ranged from 0.97 µg/L at Uncompahgre River at Colona to 16.7 µg/L at Uncompahgre River at Delta. Uncompahgre River at Delta and Whitewater were the only core sites where water samples exceeded the State of Colorado water-quality standard for dissolved selenium of 4.6 µg/L.Instantaneous 85th percentiles for dissolved selenium were calculated for sites with sufficient data

  4. Experimental limits on the proton life-time from the neutrino experiments with heavy water

    NASA Astrophysics Data System (ADS)

    Tretyak, V. I.; Zdesenko, Y. G.

    2001-04-01

    Experimental data on the number of neutrons born in the heavy water targets of the large neutrino detectors are used to set the limit on the proton life-time independently on decay mode through the reaction d-->n+?. The best up-to-date limit τp>4×1023 yr with 95% C.L. is derived from the measurements with D2O target (mass 267 kg) installed near the Bugey reactor. This value can be improved by six orders of magnitude with future data accumulated with the SNO detector containing 1000 t of D2O.

  5. Proximity to encroaching coconut palm limits native forest water use and persistence on a Pacific atoll

    USGS Publications Warehouse

    Krauss, Ken W.; Duberstein, Jamie A.; Cormier, Nicole; Young, Hillary S.; Hathaway, Stacie A.

    2015-01-01

    Competition for fresh water between native and introduced plants is one important challenge facing native forests as rainfall variability increases. Competition can be especially acute for vegetation on Pacific atolls, which depend upon consistent rainfall to replenish shallow groundwater stores. Patterns of sap flow, water use, and diameter growth of Pisonia grandis trees were investigated on Sand Islet, Palmyra Atoll, Line Islands, during a period of low rainfall. Sap flow in the outer sapwood was reduced by 53% for P. grandis trees growing within coconut palm (Cocos nucifera) stands (n = 9) versus away from coconut palm (n = 9). This suggested that water uptake was being limited by coconut palm. Radial patterns of sap flow into the sapwood of P. grandis also differed between stands with and without coconut palm, such that individual tree water use for P. grandis ranged from 14 to 67 L day−1, averaging 47·8 L day−1 without coconut palm and 23·6 L day−1 with coconut palm. Diameter growth of P. grandis was measured from nine islets. In contrast to sap flow, competition with coconut palm increased diameter growth by 89%, equating to an individual tree basal area increment of 5·4 versus 10·3 mm2 day−1. Greater diameter growth countered by lower rates of water use by P. grandis trees growing in competition with coconut palm suggests that stem swell may be associated with water storage when positioned in the understory of coconut palm, and may facilitate survival when water becomes limiting until too much shading overwhelms P. grandis. 

  6. Thermochemical water-splitting cycle, bench-scale investigations and process engineering. Annual report, October 1, 1978-September 30, 1979

    SciTech Connect

    Caprioglio, G.; McCorkle, K.H.; Besenbruch, G.E.; Rode, J.S.

    1980-03-01

    A program to investigate thermochemical water splitting has been under way at General Atomic Company (GA) since October 1972. This document is an annual progress report of Department of Energy (DOE) sponsored process development work on the GA sulfur-iodine thermochemical water splitting cycle. The work consisted of laboratory bench-scale investigations, demonstration of the process in a closed-loop cycle demonstrator, and process engineering design studies. A bench-scale system, consisting of three subunits, has been designed to study the cycle under continuous flow conditions. The designs of subunit I, which models the main solution reaction and product separation, and subunit II, which models the concentration and decomposition of sulfuric acid, were presented in an earlier annual report. The design of subunit III, which models the purification and decomposition of hydrogen iodide, is given in this report. Progress on the installation and operation of subunits I and II is described. A closed-loop cycle demonstrator was installed and operated based on a DOE request. Operation of the GA sulfur-iodine cycle was demonstrated in this system under recycle conditions. The process engineering addresses the flowsheet design of a large-scale production process consisting of four chemical sections (I through IV) and one helium heat supply section (V). The completed designs for sections I through V are presented. The thermal efficiency of the process calculated from the present flowsheet is 47%.

  7. Assessment of wildland fire impacts on watershed annual water yield: Analytical framework and case studies in the United States

    SciTech Connect

    Hallema, Dennis W.; Sun, Ge; Caldwell, Peter V.; Norman, Steven P.; Cohen, Erika C.; Liu, Yongqiang; Ward, Eric J.; McNulty, Steven G.

    2016-11-29

    More than 50% of water supplies in the conterminous United States originate on forestland or rangeland and are potentially under increasing stress as a result of larger and more severe wildfires. Little is known, however, about the long-term impacts of fire on annual water yield and the role of climate variability within this context. We here propose a framework for evaluating wildland fire impacts on streamflow that combines double-mass analysis with new methods (change point analysis, climate elasticity modeling, and process-based modeling) to distinguish between multiyear fire and climate impacts. The framework captures a wide range of fire types, watersheds characteristics, and climate conditions using streamflow data, as opposed to other approaches requiring paired watersheds. The process is illustrated with three case studies. A watershed in Arizona experienced a +266% increase in annual water yield in the 5 years after a wildfire, where +219% was attributed to wildfire and +24% to precipitation trends. In contrast, a California watershed had a lower (–64%) post-fire net water yield, comprised of enhanced flow (+38%) attributed to wildfire offset (–102%) by lower precipitation in the post-fire period. Changes in streamflow within a watershed in South Carolina had no apparent link to periods of prescribed burning but matched a very wet winter and reports of storm damage. As a result, the presented framework is unique in its ability to detect and quantify fire or other disturbances, even if the date or nature of the disturbance event is uncertain, and regardless of precipitation trends.

  8. Assessment of wildland fire impacts on watershed annual water yield: Analytical framework and case studies in the United States

    DOE PAGES

    Hallema, Dennis W.; Sun, Ge; Caldwell, Peter V.; ...

    2016-11-29

    More than 50% of water supplies in the conterminous United States originate on forestland or rangeland and are potentially under increasing stress as a result of larger and more severe wildfires. Little is known, however, about the long-term impacts of fire on annual water yield and the role of climate variability within this context. We here propose a framework for evaluating wildland fire impacts on streamflow that combines double-mass analysis with new methods (change point analysis, climate elasticity modeling, and process-based modeling) to distinguish between multiyear fire and climate impacts. The framework captures a wide range of fire types, watershedsmore » characteristics, and climate conditions using streamflow data, as opposed to other approaches requiring paired watersheds. The process is illustrated with three case studies. A watershed in Arizona experienced a +266% increase in annual water yield in the 5 years after a wildfire, where +219% was attributed to wildfire and +24% to precipitation trends. In contrast, a California watershed had a lower (–64%) post-fire net water yield, comprised of enhanced flow (+38%) attributed to wildfire offset (–102%) by lower precipitation in the post-fire period. Changes in streamflow within a watershed in South Carolina had no apparent link to periods of prescribed burning but matched a very wet winter and reports of storm damage. As a result, the presented framework is unique in its ability to detect and quantify fire or other disturbances, even if the date or nature of the disturbance event is uncertain, and regardless of precipitation trends.« less

  9. The Agony of Choice: How Plants Balance Growth and Survival under Water-Limiting Conditions1

    PubMed Central

    Claeys, Hannes; Inzé, Dirk

    2013-01-01

    When confronted with water limitation, plants actively reprogram their metabolism and growth. Recently, it has become clear that growing tissues show specific and highly dynamic responses to drought, which differ from the well-studied responses in mature tissues. Here, we provide an overview of recent advances in understanding shoot growth regulation in water-limiting conditions. Of special interest is the balance between maintained growth and competitiveness on the one hand and ensured survival on the other hand. A number of master regulators controlling this balance have been identified, such as DELLAs and APETALA2/ETHYLENE RESPONSE FACTOR-type transcription factors. The possibilities of engineering or breeding crops that maintain growth in periods of mild drought, while still being able to activate protective tolerance mechanisms, are discussed. PMID:23766368

  10. Unravelling Carbon Fixation under Nutrient limited Conditions - a Water Column Perspective

    NASA Astrophysics Data System (ADS)

    Thomas, Helmuth; Craig, Susanne; Shadwick, Elizabeth H.; Li, William K.; Greenan, Blair J. W.

    2014-05-01

    Phytoplankton plays a critical role in the uptake of atmospheric carbon dioxide (CO2) by the ocean, and is comprised of a spectrum of cell sizes that are strongly regulated by oceanographic conditions. Elevated CO2 fixation relative to nutrient availability, also called carbon overconsumption, has been observed in various mid to high latitude systems, such as the Baltic and North Seas, the North Atlantic Ocean, the Canadian Arctic Archipelago or the Scotian Shelf. We shed light on this phenomenon relying on an extensive data set of water column observations of the CO2 system and phytoplankton cell counts from the Scotian Shelf, a temperate shelf sea. We show that in the summertime, the population of numerically abundant small cells, which favour warmer, nutrient poor conditions, accounts for approximately 20% of annual carbon uptake. At the broader scale, the neglection of this "non-Redfieldian" contribution typically leads to an underestimation of net community production by approximately 20% to 50%. These small cells are not well represented by chlorophyll a - the ubiquitously used proxy of phytoplankton biomass - but rather, are strongly correlated with surface water temperature. Given the persistent near-zero nutrient concentrations during the summer, it appears that small cells drive carbon overconsumption, and suggest that their role in carbon fixation will become increasingly important in a warming, increasingly stratified ocean.

  11. Using the optimality hypothesis to predict vegetation indices in a water limited environment

    NASA Astrophysics Data System (ADS)

    van der Tol, C.; Meesters, A.; Dolman, H.; Waterloo, M.

    2009-12-01

    In two recent papers, a conceptual model was presented to predict optimum vegetation parameters given climatic constraints (Van der Tol et al., WRR 44 W03421 & W03422, 2008). The vegetation parameters used in these papers, notably photosynthetic capacity and a water use efficiency parameter, are relevant for the cycles of carbon and water. These parameters are not constants, but functions of the available soil moisture and atmospheric conditions. The model is based on the assumption, that photosynthesis and transpiration are regulated in such a way, that net growth is maximised. The model was tested using field measurements of micrometeorological variables, sap flow, 13C-isotope and chemical analysis of leaves, in undisturbed sub-Mediterranean forests. The model reproduced the observed seasonal course of transpiration, both in a dry and an average year, and both on a north and a south facing slope. As a next step, the model has been tested for a larger spatial scale, by using time series of precipitation, humidity and NDVI for selected sites on the Iberian Peninsula, across a gradient of increasing annual precipitation.

  12. The hydrological effects of varying vegetation characteristics in a temperate water-limited basin: Development of the dynamic Budyko-Choudhury-Porporato (dBCP) model

    NASA Astrophysics Data System (ADS)

    Liu, Qiang; McVicar, Tim R.; Yang, Zhifeng; Donohue, Randall J.; Liang, Liqiao; Yang, Yuting

    2016-12-01

    Vegetation patterns are affected by water availability, which, in turn, influences the hydrological partitioning and regional water balance, especially in water-limited regions. Considering the important role of vegetation in partitioning the catchment water yield, the recently developed Budyko-Choudhury-Porporato (or BCP) model incorporated Porporato's model of key ecohydrological processes into Choudury's form of the Budyko hydroclimatic framework. Here we extend the steady state BCP model by incorporating dynamic ecohydrological processes into it and combining it with a typical bucket soil water balance model (resulting in the dynamic BCP, or dBCP, model). The dBCP model is used here to assess the impacts of vegetation on the water balance in a temperate water-limited basin (i.e., the Yellow River Basin (YRB) in north China), where growing season phenology is primarily constrained by low temperatures. The results show that: (i) the incorporation of dynamic growing season (fs) and dynamic effective rooting depth (Ze) conditions into the dBCP model improves results when compared to the original BCP model; (ii) dBCP model's results vary depending on time-step used (i.e., we tested mean-annual to monthly), which reflected the influence of catchment variables, e.g., catchment area, catchment-average air temperature, dryness index and Ze; and (iii) actual evapotranspiration (E) is more sensitive to changes in mean storm depth (α), followed by P, Ze, and Ep. When taking into account observed variability of each of four ecohydrological variables, changes in Ze cause the greatest variability in E, generally followed by variability in P and α, and then Ep. The dBCP results indicate that incorporating dynamic ecohydrological processes into the Budyko framework can improve the estimation of inter-annual variability of the regional water balance. This can help to understand the water requirement and to establish suitable water management strategies to adapt to climate

  13. Investigation of detection limits for solutes in water measured by laser raman spectrometry

    USGS Publications Warehouse

    Goldberg, M.C.

    1977-01-01

    The influence of experimental parameters on detection sensitivity was determined for laser Raman analysis of dissolved solutes in water. Individual solutions of nitrate, sulfate, carbonate, bicarbonate, monohydrogen phosphate, dihydrogen phosphate, acetate ion, and acetic acid were measured. An equation is derived which expresses the signal-to-noise ratio in terms of solute concentration, measurement time, spectral slit width, laser power fluctuations, and solvent background intensity. Laser beam intensity fluctuations at the sample and solvent background intensity are the most important limiting factors.

  14. Analyzing the Limitations and the Applicability Domain of Water-Sediment Transformation Tests like OECD 308.

    PubMed

    Ter Horst, Mechteld M S; Koelmans, Albert A

    2016-10-04

    The assessment of chemical degradation rates from water-sediment experiments like for instance OECD 308 is challenging due to parallel occurrence of processes like degradation, sorption and diffusive transport, at different rates in water and sediment or at their interface. To systematically and quantitatively analyze this limitation, we generated artificial experiment data sets using model simulations and then used these data sets in an inverse modeling exercise to estimate degradation half-lives in water and sediment (DegT50wat and DegT50sed), which then were evaluated against their true values. Results were visualized by chemical space diagrams that identified those substance property combinations for which the OECD 308 test is fundamentally inappropriate. We show that the uncertainty in estimated degradation half-lives in water increases as the process of diffusion to the sediment becomes dominant over degradation in the water. We show that in theory the uncertainty in the estimated DegT50sed is smaller than the uncertainty in the DegT50wat. The predictive value of our chemical space diagrams was validated using literature transformation rates and their uncertainties that were inferred from real water-sediment experiments.

  15. Annual Cycles of Deep-ocean, Biogeochemical Export Fluxes and Biological Pump Processes in Subtropical and Subantarctic Waters, Southwest Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Nodder, S.; Chiswell, S.; Northcote, L.

    2016-02-01

    One of the key aspects of the global carbon cycle is the efficiency and spatio-temporal variability of the biological pump. In this paper, the annual cycles of particle fluxes, derived from moored sediment trap data collected from 2000-12 in subtropical (STW) and subantarctic waters (SAW), east of New Zealand, are presented. These observations are the most comprehensive export flux time-series from temperate Southern Hemisphere latitudes to date. With high levels of variability, fluxes in SAW were markedly lower than in STW, reflecting the picophytoplankton-dominated communities in the iron-limited, high nutrient-low chlorophyll SAW. Austral spring chlorophyll blooms in surface STW were near-synchronous with elevated fluxes of bio-siliceous, carbonate and organic carbon-rich materials to the deep ocean, probably facilitated by diatom sedimentation. Lithogenic fluxes were also high in STW, compared to SAW, reflecting proximity to the New Zealand landmass. In contrast, the highest biogenic fluxes in SAW occurred in spring when surface chlorophyll concentrations were low, while highest annual chlorophyll concentrations were in summer with no associated flux increase. We hypothesize that the high spring export in SAW occurs from subsurface chlorophyll accumulations that are not evident from remote-sensing satellites. This material was also rich in biogenic silica, perhaps related to the preferential export of diatoms and other silica-producing organisms, such as silicoflagellates and radiolarians. Particle fluxes in STW are similar to that of other mesotrophic to oligotrophic waters ( 6-7 mgC m-2 d-1), whereas export from SAW is below global averages ( 3 mgC m-2 d-1), and is characterized by carbonate-dominated and prominent bio-siliceous deposition.

  16. Linking carbon and water limitations to drought-induced mortality of Pinus flexilis seedlings

    USGS Publications Warehouse

    Reinhardt, Keith; Germino, Matthew J.; Kueppers, Lara M.; Domec, Jean-Christophe; Mitton, Jeffry

    2015-01-01

    Survival of tree seedlings at high elevations has been shown to be limited by thermal constraints on carbon balance, but it is unknown if carbon relations also limit seedling survival at lower elevations, where water relations may be more important. We measured and modeled carbon fluxes and water relations in first-year Pinus flexilis seedlings in garden plots just beyond the warm edge of their natural range, and compared these with dry-mass gain and survival across two summers. We hypothesized that mortality in these seedlings would be associated with declines in water relations, more so than with carbon-balance limitations. Rather than gradual declines in survivorship across growing seasons, we observed sharp, large-scale mortality episodes that occurred once volumetric soil-moisture content dropped below 10%. By this point, seedling water potentials had decreased below −5 MPa, seedling hydraulic conductivity had decreased by 90% and seedling hydraulic resistance had increased by >900%. Additionally, non-structural carbohydrates accumulated in aboveground tissues at the end of both summers, suggesting impairments in phloem-transport from needles to roots. This resulted in low carbohydrate concentrations in roots, which likely impaired root growth and water uptake at the time of critically low soil moisture. While photosynthesis and respiration on a leaf area basis remained high until critical hydraulic thresholds were exceeded, modeled seedling gross primary productivity declined steadily throughout the summers. At the time of mortality, modeled productivity was insufficient to support seedling biomass-gain rates, metabolism and secondary costs. Thus the large-scale mortality events that we observed near the end of each summer were most directly linked with acute, episodic declines in plant hydraulic function that were linked with important changes in whole-seedling carbon relations.

  17. Annual water resources review, White Sands Missile Range, New Mexico, 1980

    USGS Publications Warehouse

    Cruz, R.R.

    1981-01-01

    Ground-water data were collected in 1980 at White Sands Missile Range in south-central New Mexico. The total water pumped at White Sands Missile Range in 1980 was 725,053,000 gallons, which was 32.5 million gallons more than in 1979. The Post Headquarters well field, which produces more than 98 percent of the water used at White Sands Missile Range, pumped 712,909,000 gallons, which was 31.1 million gallons more in 1980 than in 1979. Data were collected for specific Range areas north of the Post Headquarters area that might have potential for future water-supply development. (USGS)

  18. Annual water-resources review, White Sands Missile Range, New Mexico

    USGS Publications Warehouse

    Cruz, R.R.

    1983-01-01

    Ground-water data were collected in 1982 at White Sands Missile Range in south-central New Mexico. Depth-to-water measurements in the Post Headquarters supply wells continued to show seasonal declines. Test wells east of the Headquarters well field continue to show long-term declines as well as seasonal fluctuations. The total amount of water pumped from White Sands Missile Range supply wells was 66,226,600 gallons more in 1982 than in 1981. The difference in the specific-conductance values of the water samples collected from the Post Headquarters supply wells in the winter and summer increased in 1982. (USGS)

  19. Impacts of Water Level Fluctuations on Kokanee Reproduction in Flathead Lake, 1984 Annual Report.

    SciTech Connect

    Decker-Hess, Janet; Clancey, Patrick

    1984-03-01

    This study was initiated in the fall of 1981 to delineate the extent of successful shoreline spawning of kokanee salmon in Flathead Lake and determine the impacts of the historic and present operations of Kerr and Hungry Horse dams. An investigation of the quantity and quality of groundwater and other factors affecting kokanee reproductive success in Flathead Lake began in the spring of 1982. A total of 719 redds were counted in 17 shoreline areas of Flathead Lake in1983 compared to 592 in 1981 and 1,029 in 1982. Shoreline spawning contributed three percent to the total kokanee spawning in the Flathead drainage in 1983. Fifty-nine percent of the redds were located above 2883 ft, the operational minimum pool. The majority of those redds were constructed between 2885 and 2889 ft. In areas above minimum pool, intergravel dissolved oxygen concentrations were adequate for embryo survival and exhibited a decrease with depth. Limited data indicated apparent velocity may be the key in determining redd distribution. Seventy-five percent of the redds located below minimum pool were constructed in a zone between 2869 and 2883 ft. In individual areas, apparent velocity measurements and intergravel dissolved oxygen concentrations were related to redd density. The variation in intergravel dissolved oxygen concentrations in the Yellow Bay spawning area was partially explained by lake stage fluctuation. As lake stage declined, groundwater apparent velocity increased which increased intergravel dissolved oxygen concentrations. Mean survival to the eyed stage in the three areas below minimum pool was 43 percent. Prior to exposure by lake drawdown, mean survival to the eyed stage in spawning areas above minimum pool was 87 percent. This indicated habitat most conducive to successful embryo survival was in gravels above 2883 ft. prior to significant exposure. Survival in redds exposed to either extended periods of drawdown or to temperatures less than -10% was significantly reduced to

  20. Methods for estimating annual exceedance probability discharges for streams in Arkansas, based on data through water year 2013

    USGS Publications Warehouse

    Wagner, Daniel M.; Krieger, Joshua D.; Veilleux, Andrea G.

    2016-08-04

    In 2013, the U.S. Geological Survey initiated a study to update regional skew, annual exceedance probability discharges, and regional regression equations used to estimate annual exceedance probability discharges for ungaged locations on streams in the study area with the use of recent geospatial data, new analytical methods, and available annual peak-discharge data through the 2013 water year. An analysis of regional skew using Bayesian weighted least-squares/Bayesian generalized-least squares regression was performed for Arkansas, Louisiana, and parts of Missouri and Oklahoma. The newly developed constant regional skew of -0.17 was used in the computation of annual exceedance probability discharges for 281 streamgages used in the regional regression analysis. Based on analysis of covariance, four flood regions were identified for use in the generation of regional regression models. Thirty-nine basin characteristics were considered as potential explanatory variables, and ordinary least-squares regression techniques were used to determine the optimum combinations of basin characteristics for each of the four regions. Basin characteristics in candidate models were evaluated based on multicollinearity with other basin characteristics (variance inflation factor < 2.5) and statistical significance at the 95-percent confidence level (p ≤ 0.05). Generalized least-squares regression was used to develop the final regression models for each flood region. Average standard errors of prediction of the generalized least-squares models ranged from 32.76 to 59.53 percent, with the largest range in flood region D. Pseudo coefficients of determination of the generalized least-squares models ranged from 90.29 to 97.28 percent, with the largest range also in flood region D. The regional regression equations apply only to locations on streams in Arkansas where annual peak discharges are not substantially affected by regulation, diversion, channelization, backwater, or urbanization