WorldWideScience

Sample records for cumulative watershed effects

  1. Predicting Cumulative Watershed Effects using Spatially Explicit Models

    Science.gov (United States)

    MacDonald, L. H.; Litschert, S.

    2004-12-01

    Cumulative watershed effects /(CWEs/) result from the combined effects of land disturbances distributed over both space and time. They are of concern because changes in flow and sediment yields can adversely affect aquatic habitat, channel morphology, water yields, and water quality. The assessment procedures currently used by agencies such as the U.S. Forest Service generally rely on a lumped approach to quantify disturbance, despite the widespread recognition that site conditions and location do matter! The overall goal of our work is to develop spatially-explicit models to quantify changes in flow and sediment yields. Key objectives include: use of readily available GIS data; ease of use for resource managers with minimal GIS experience; modularity so that models can be added or updated; and allowing users to select the models and values for key parameters. The DeltaQ model calculates changes in peak, median, and low flows due to forest management activities and fires. Inputs include GIS data with disturbance polygons, an initial change in flow rate, and the time to recovery. Data from paired watershed studies are provided to help guide the user. The initial version of FORest Erosion Simulation Tools /(FOREST/) calculates sediment production from forest harvest, fires, and unpaved roads. Additional modules are being developed to deliver this sediment to the stream channel and route it to downstream locations. In accordance with our objectives, the user can predict sediment production rates using different empirical equations, assign an initial sediment production rate and a specified linear recovery period, or develop a look-up table based on local knowledge, published values, or data from other models such as WEPP. The required GIS layers vary according to the model/(s/) selected, but generally include past disturbances /(e.g., fires and timber harvest/), roads, and elevation. Outputs include GIS layers and text files that can be subjected to additional

  2. Estimating multi-factor cumulative watershed effects on fish populations with an individual-based model

    Science.gov (United States)

    Bret C. Harvey; Steven F. Railsback

    2007-01-01

    While the concept of cumulative effects is prominent in legislation governing environmental management, the ability to estimate cumulative effects remains limited. One reason for this limitation is that important natural resources such as fish populations may exhibit complex responses to changes in environmental conditions, particularly to alteration of multiple...

  3. The effects of cumulative forest disturbance on streamflow in a large watershed in the central interior of British Columbia, Canada

    Directory of Open Access Journals (Sweden)

    M. Zhang

    2012-07-01

    Full Text Available The Baker Creek watershed (1570 km2, situated in the central interior of British Columbia, Canada, has been severely disturbed by both logging and natural disturbance, particularly by a recent large-scale mountain pine beetle (MPB infestation (up to 2009, 70.2% of the watershed area had been attacked by MPB and subsequent salvage logging. The concept of equivalent clear-cut area (ECA was used to indicate the magnitude of forest disturbance, with consideration of hydrological recovery following various types of disturbance (wildfire, logging and MPB infestation, cumulated over space and time in the watershed. The cumulative ECA peaked at 62.2% in 2009. A combined approach of statistical analysis (i.e. time series analysis and graphic method (modified double mass curve was employed to evaluate the impacts of forest disturbance on hydrology. Our results showed that severe forest disturbance significantly increased annual mean flow. The average increment in annual mean flow caused by forest disturbance was 48.4 mm yr−1, while the average decrease in annual mean flow caused by climatic variability during the same disturbance period was 35.5 mm yr−1. The opposite changes in directions and magnitudes clearly suggest an offsetting effect between forest disturbance and climatic variability, with the absolute influential strength of forest disturbance (57.7% overriding that from climate variability (42.3%. Forest disturbance also produced significant positive effects on low flow and dry season (fall and winter mean flow. Implications of our findings for future forest and water resources management are discussed in the context of long-term watershed sustainability.

  4. The cumulative effects of forest disturbance on streamflow in a large watershed in the central interior of British Columbia, Canada

    Science.gov (United States)

    Zhang, M.; Wei, X.

    2012-03-01

    The Baker Creek watershed (1570 km2) situated in the central interior of British Columbia, Canada has been severely disturbed by both human-being logging and natural disturbance, particularly by a recent large-scale mountain pine beetle (MPB) infestation (up to 2009, 70.2% of the watershed area was attacked by MPB) and subsequent salvage logging. The concept of equivalent clear-cut area (ECA) was used to indicate the magnitude of forest disturbance with consideration of hydrological recovery following various types of disturbances (wildfire, logging and MPB infestation) cumulated over space and time in the studied watershed. The cumulative ECA was up to 62.2% in 2009. A combined approach of statistical analysis (time series analysis) with modified double mass curve was employed to evaluate the impacts of forest disturbance on hydrology. Our results showed that severe forest disturbance significantly increased annual mean flow. The average increment in annual mean flow caused by forest disturbance was 48.4 mm yr-1, while the average decrease in annual mean flow caused by climatic variability during the same disturbance period was -35.5 mm yr-1. The opposite change directions and magnitudes clearly suggest offsetting effect between forest disturbance and climatic variability, with the absolute influential strength of forest disturbance (57.7%) overriding that from climate variability (42.3%). Forest disturbances also produced significant positive effect on low flow and dry season (fall and winter) mean flow. Implications of our findings for future forest and water resources management are discussed in the context of long-term watershed sustainability.

  5. The cumulative effects of forest disturbance on streamflow in a large watershed in the central interior of British Columbia, Canada

    Directory of Open Access Journals (Sweden)

    M. Zhang

    2012-03-01

    Full Text Available The Baker Creek watershed (1570 km2 situated in the central interior of British Columbia, Canada has been severely disturbed by both human-being logging and natural disturbance, particularly by a recent large-scale mountain pine beetle (MPB infestation (up to 2009, 70.2% of the watershed area was attacked by MPB and subsequent salvage logging. The concept of equivalent clear-cut area (ECA was used to indicate the magnitude of forest disturbance with consideration of hydrological recovery following various types of disturbances (wildfire, logging and MPB infestation cumulated over space and time in the studied watershed. The cumulative ECA was up to 62.2% in 2009. A combined approach of statistical analysis (time series analysis with modified double mass curve was employed to evaluate the impacts of forest disturbance on hydrology. Our results showed that severe forest disturbance significantly increased annual mean flow. The average increment in annual mean flow caused by forest disturbance was 48.4 mm yr−1, while the average decrease in annual mean flow caused by climatic variability during the same disturbance period was −35.5 mm yr−1. The opposite change directions and magnitudes clearly suggest offsetting effect between forest disturbance and climatic variability, with the absolute influential strength of forest disturbance (57.7% overriding that from climate variability (42.3%. Forest disturbances also produced significant positive effect on low flow and dry season (fall and winter mean flow. Implications of our findings for future forest and water resources management are discussed in the context of long-term watershed sustainability.

  6. The effects of cumulative forest disturbance on streamflow in a large watershed in the central interior of British Columbia, Canada

    Science.gov (United States)

    Zhang, M.; Wei, X.

    2012-07-01

    The Baker Creek watershed (1570 km2), situated in the central interior of British Columbia, Canada, has been severely disturbed by both logging and natural disturbance, particularly by a recent large-scale mountain pine beetle (MPB) infestation (up to 2009, 70.2% of the watershed area had been attacked by MPB) and subsequent salvage logging. The concept of equivalent clear-cut area (ECA) was used to indicate the magnitude of forest disturbance, with consideration of hydrological recovery following various types of disturbance (wildfire, logging and MPB infestation), cumulated over space and time in the watershed. The cumulative ECA peaked at 62.2% in 2009. A combined approach of statistical analysis (i.e. time series analysis) and graphic method (modified double mass curve) was employed to evaluate the impacts of forest disturbance on hydrology. Our results showed that severe forest disturbance significantly increased annual mean flow. The average increment in annual mean flow caused by forest disturbance was 48.4 mm yr-1, while the average decrease in annual mean flow caused by climatic variability during the same disturbance period was 35.5 mm yr-1. The opposite changes in directions and magnitudes clearly suggest an offsetting effect between forest disturbance and climatic variability, with the absolute influential strength of forest disturbance (57.7%) overriding that from climate variability (42.3%). Forest disturbance also produced significant positive effects on low flow and dry season (fall and winter) mean flow. Implications of our findings for future forest and water resources management are discussed in the context of long-term watershed sustainability.

  7. Development of a "Hydrologic Equivalent Wetland" Concept for Modeling Cumulative Effects of Wetlands on Watershed Hydrology

    Science.gov (United States)

    Wang, X.; Liu, T.; Li, R.; Yang, X.; Duan, L.; Luo, Y.

    2012-12-01

    Wetlands are one of the most important watershed microtopographic features that affect, in combination rather than individually, hydrologic processes (e.g., routing) and the fate and transport of constituents (e.g., sediment and nutrients). Efforts to conserve existing wetlands and/or to restore lost wetlands require that watershed-level effects of wetlands on water quantity and water quality be quantified. Because monitoring approaches are usually cost or logistics prohibitive at watershed scale, distributed watershed models, such as the Soil and Water Assessment Tool (SWAT), can be a best resort if wetlands can be appropriately represented in the models. However, the exact method that should be used to incorporate wetlands into hydrologic models is the subject of much disagreement in the literature. In addition, there is a serious lack of information about how to model wetland conservation-restoration effects using such kind of integrated modeling approach. The objectives of this study were to: 1) develop a "hydrologic equivalent wetland" (HEW) concept; and 2) demonstrate how to use the HEW concept in SWAT to assess effects of wetland restoration within the Broughton's Creek watershed located in southwestern Manitoba of Canada, and of wetland conservation within the upper portion of the Otter Tail River watershed located in northwestern Minnesota of the United States. The HEWs were defined in terms of six calibrated parameters: the fraction of the subbasin area that drains into wetlands (WET_FR), the volume of water stored in the wetlands when filled to their normal water level (WET_NVOL), the volume of water stored in the wetlands when filled to their maximum water level (WET_MXVOL), the longest tributary channel length in the subbasin (CH_L1), Manning's n value for the tributary channels (CH_N1), and Manning's n value for the main channel (CH_N2). The results indicated that the HEW concept allows the nonlinear functional relations between watershed processes

  8. The cumulative effects of forest disturbance on streamflow in a large watershed in the central interior of British Columbia, Canada

    OpenAIRE

    Zhang, M.; X Wei

    2012-01-01

    The Baker Creek watershed (1570 km2) situated in the central interior of British Columbia, Canada has been severely disturbed by both human-being logging and natural disturbance, particularly by a recent large-scale mountain pine beetle (MPB) infestation (up to 2009, 70.2% of the watershed area was attacked by MPB) and subsequent salvage logging. The concept of equivalent clear-cut area (ECA) was used to indicate the magnitude of forest disturbance with consideration of...

  9. The effects of cumulative forest disturbance on streamflow in a large watershed in the central interior of British Columbia, Canada

    OpenAIRE

    Zhang, M.; X Wei

    2012-01-01

    The Baker Creek watershed (1570 km2), situated in the central interior of British Columbia, Canada, has been severely disturbed by both logging and natural disturbance, particularly by a recent large-scale mountain pine beetle (MPB) infestation (up to 2009, 70.2% of the watershed area had been attacked by MPB) and subsequent salvage logging. The concept of equivalent clear-cut area (ECA) was used to indicate the magnitude of forest disturbance, with consideration of hyd...

  10. Cumulative environmental effects. Summary

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    This report presents a compilation of knowledge about the state of the environment and human activity in the Norwegian part of the North Sea and Skagerrak. The report gives an overview of pressures and impacts on the environment from normal activity and in the event of accidents. This is used to assess the cumulative environmental effects, which factors have most impact and where the impacts are greatest, and to indicate which problems are expected to be most serious in the future. The report is intended to provide relevant information that can be used in the management of the marine area in the future. It also provides input for the identification of environmental targets and management measures for the North Sea and Skagerrak.(Author)

  11. Long and Short Term Cumulative Structural Priming Effects

    OpenAIRE

    Kaschak, Michael P.; Kutta, Timothy J.; Coyle, Jacqueline M.

    2012-01-01

    We present six experiments that examine cumulative structural priming effects (i.e., structural priming effects that accumulate across many utterances). Of particular interest is whether (1) cumulative priming effects transfer across language production tasks and (2) the transfer of cumulative priming effects across tasks persists over the course of a week. Our data suggest that cumulative structural priming effects do transfer across language production tasks (e.g., from written stem complet...

  12. Long and Short Term Cumulative Structural Priming Effects.

    Science.gov (United States)

    Kaschak, Michael P; Kutta, Timothy J; Coyle, Jacqueline M

    We present six experiments that examine cumulative structural priming effects (i.e., structural priming effects that accumulate across many utterances). Of particular interest is whether (1) cumulative priming effects transfer across language production tasks and (2) the transfer of cumulative priming effects across tasks persists over the course of a week. Our data suggest that cumulative structural priming effects do transfer across language production tasks (e.g., from written stem completion to picture description, and from picture description to written stem completion), but only when both tasks are presented in the same experimental session. When cumulative priming effects are established in one task, and the second (changed) task is not presented until a week later, the cumulative priming effects are not observed.

  13. Cumulative Effect of Depression on Dementia Risk

    Directory of Open Access Journals (Sweden)

    J. Olazarán

    2013-01-01

    Full Text Available Objective. To analyze a potential cumulative effect of life-time depression on dementia and Alzheimer’s disease (AD, with control of vascular factors (VFs. Methods. This study was a subanalysis of the Neurological Disorders in Central Spain (NEDICES study. Past and present depression, VFs, dementia status, and dementia due to AD were documented at study inception. Dementia status was also documented after three years. Four groups were created according to baseline data: never depression (nD, past depression (pD, present depression (prD, and present and past depression (prpD. Logistic regression was used. Results. Data of 1,807 subjects were investigated at baseline (mean age 74.3, 59.3% women, and 1,376 (81.6% subjects were evaluated after three years. The prevalence of dementia at baseline was 6.7%, and dementia incidence was 6.3%. An effect of depression was observed on dementia prevalence (OR [CI 95%] 1.84 [1.01–3.35] for prD and 2.73 [1.08–6.87] for prpD, and on dementia due to AD (OR 1.98 [0.98–3.99] for prD and OR 3.98 [1.48–10.71] for prpD (fully adjusted models, nD as reference. Depression did not influence dementia incidence. Conclusions. Present depression and, particularly, present and past depression are associated with dementia at old age. Multiple mechanisms, including toxic effect of depression on hippocampal neurons, plausibly explain these associations.

  14. Cumulative Effects of Human Activities on Marine Mammal Populations

    Science.gov (United States)

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Cumulative Effects of Human Activities on Marine Mammal ...marine mammals . OBJECTIVES The National Academies of Sciences, Engineering, and Medicine has convened a volunteer committee that will...Review the present scientific understanding of cumulative effects of anthropogenic stressors on marine mammals with a focus on anthropogenic sound

  15. Engaging Watershed Stakeholders for Cost-Effective Environmental Management Planning with "Watershed Manager"

    Science.gov (United States)

    Williams, Jeffery R.; Smith, Craig M.; Roe, Josh D.; Leatherman, John C.; Wilson, Robert M.

    2012-01-01

    "Watershed Manager" is a spreadsheet-based model that is used in extension education programs for learning about and selecting cost-effective watershed management practices to reduce soil, nitrogen, and phosphorus losses from cropland. It can facilitate Watershed Restoration and Protection Strategy (WRAPS) stakeholder groups' development…

  16. Engaging Watershed Stakeholders for Cost-Effective Environmental Management Planning with "Watershed Manager"

    Science.gov (United States)

    Williams, Jeffery R.; Smith, Craig M.; Roe, Josh D.; Leatherman, John C.; Wilson, Robert M.

    2012-01-01

    "Watershed Manager" is a spreadsheet-based model that is used in extension education programs for learning about and selecting cost-effective watershed management practices to reduce soil, nitrogen, and phosphorus losses from cropland. It can facilitate Watershed Restoration and Protection Strategy (WRAPS) stakeholder groups' development…

  17. Engaging Watershed Stakeholders for Cost-Effective Environmental Management Planning with "Watershed Manager"

    Science.gov (United States)

    Williams, Jeffery R.; Smith, Craig M.; Roe, Josh D.; Leatherman, John C.; Wilson, Robert M.

    2012-01-01

    "Watershed Manager" is a spreadsheet-based model that is used in extension education programs for learning about and selecting cost-effective watershed management practices to reduce soil, nitrogen, and phosphorus losses from cropland. It can facilitate Watershed Restoration and Protection Strategy (WRAPS) stakeholder groups' development of…

  18. The Contribution of Project Environmental Assessment to Assessing and Managing Cumulative Effects: Individually and Collectively Insignificant?

    Science.gov (United States)

    Noble, Bram; Liu, Jialang; Hackett, Paul

    2017-04-01

    This paper explores the opportunities and constraints to project-based environmental assessment as a means to support the assessment and management of cumulative environmental effects. A case study of the hydroelectric sector is used to determine whether sufficient information is available over time through project-by-project assessments to support an adequate understanding of cumulative change. Results show inconsistency from one project to the next in terms of the components and indicators assessed, limited transfer of baseline information between project assessments over time, and the same issues and concerns being raised by review panels-even though the projects reviewed are operating in the same watershed and operated by the same proponent. Project environmental assessments must be managed, and coordinated, as part of a larger system of impact assessment, if project-by-project assessments are to provide a meaningful forum for learning and understanding cumulative change. The paper concludes with recommendations for improved project-based assessment practice in support of cumulative effects assessment and management.

  19. Solid-state electro-cumulation effect numerical simulation

    CERN Document Server

    Grishin, V G

    2001-01-01

    It is an attempt to simulate as really as possible a crystal's interatomic interaction under conditions of "Solid-state electro-cumulation (super-polarization) effect". Some theoretical and experimental reasons to believe that within solid substances an interparticles interaction could concentrate from the surface to a centre were given formerly. Now, numerical results show the conditions that could make the cumulation more effective. Another keywords: ion, current, solid, symmetry, cumulation, polarization, depolarization, ionic conductor,superionic conductor, ice, crystal, strain, V-center, V-centre, doped crystal, interstitial impurity, intrinsic color center, high pressure technology, Bridgman, anvil, experiment, crowdion, dielectric, proton, layer, defect, lattice, dynamics, electromigration, mobility, muon catalysis, concentration, doping, dopant, conductivity, pycnonuclear reaction, permittivity, dielectric constant, point defects, interstitials, polarizability, imperfection, defect centers, glass, epi...

  20. Effect of correlation on cumulants in heavy-ion collisions

    CERN Document Server

    Mishra, D K; Netrakanti, P K

    2015-01-01

    We study the effects of correlation on cumulants and their ratios of net-proton multiplicity distribution which have been measured for central (0-5\\%) Au+Au collisions at Relativistic Heavy Ion Collider (RHIC). This effect has been studied assuming individual proton and anti-proton distributions as Poisson or Negative Binomial Distribution (NBD). In-spite of significantly correlated production due to baryon number, electric charge conservation and kinematical correlations of protons and anti-protons, the measured cumulants of net-proton distribution follow the independent production model. In the present work we demonstrate how the introduction of correlations will affect the cumulants and their ratios for the difference distributions. We have also demonstrated this study using the proton and anti-proton distributions obtained from HIJING event generator.

  1. The effects of cumulative practice on mathematics problem solving.

    Science.gov (United States)

    Mayfield, Kristin H; Chase, Philip N

    2002-01-01

    This study compared three different methods of teaching five basic algebra rules to college students. All methods used the same procedures to teach the rules and included four 50-question review sessions interspersed among the training of the individual rules. The differences among methods involved the kinds of practice provided during the four review sessions. Participants who received cumulative practice answered 50 questions covering a mix of the rules learned prior to each review session. Participants who received a simple review answered 50 questions on one previously trained rule. Participants who received extra practice answered 50 extra questions on the rule they had just learned. Tests administered after each review included new questions for applying each rule (application items) and problems that required novel combinations of the rules (problem-solving items). On the final test, the cumulative group outscored the other groups on application and problem-solving items. In addition, the cumulative group solved the problem-solving items significantly faster than the other groups. These results suggest that cumulative practice of component skills is an effective method of training problem solving.

  2. Experience of cumulative effects assessment in the UK

    Directory of Open Access Journals (Sweden)

    Piper Jake

    2004-01-01

    Full Text Available Cumulative effects assessment (CEA is a development of environmental impact assessment which attempts to take into account the wider picture of what impacts may affect the environment as a result of either multiple or linear projects, or development plans. CEA is seen as a further valuable tool in promoting sustainable development. The broader canvas upon which the assessment is made leads to a suite of issues such as complexity in methods and assessment of significance, the desirability of co-operation between developers and other parties, new ways of addressing mitigation and monitoring. After outlining the legislative position and the process of CEA, this paper looks at three cases studies in the UK where cumulative assessment has been carried out - the cases concern wind farms, major infrastructure and off-shore developments.

  3. EFFECTS OF HYDROGEOMORPHIC REGION, WATERSHED STORAGE, AND FOREST FRAGMENTATION ON WATERSHED EXPORTS

    Science.gov (United States)

    Turbidity was highest for South Shore streams overall, but exhibited a significant HGM x storage x fragmentation effect, with highest levels observed in South Shore low storage/high fragmentation watersheds.

  4. Cumulative Effects Assessment: Linking Social, Ecological, and Governance Dimensions

    Directory of Open Access Journals (Sweden)

    Marian Weber

    2012-06-01

    Full Text Available Setting social, economic, and ecological objectives is ultimately a process of social choice informed by science. In this special feature we provide a multidisciplinary framework for the use of cumulative effects assessment in land use planning. Forest ecosystems are facing considerable challenges driven by population growth and increasing demands for resources. In a suite of case studies that span the boreal forest of Western Canada to the interior Atlantic forest of Paraguay we show how transparent and defensible methods for scenario analysis can be applied in data-limited regions and how social dimensions of land use change can be incorporated in these methods, particularly in aboriginal communities that have lived in these ecosystems for generations. The case studies explore how scenario analysis can be used to evaluate various land use options and highlight specific challenges with identifying social and ecological responses, determining thresholds and targets for land use, and integrating local and traditional knowledge in land use planning. Given that land use planning is ultimately a value-laden and often politically charged process we also provide some perspective on various collective and expert-based processes for identifying cumulative impacts and thresholds. The need for good science to inform and be informed by culturally appropriate democratic processes calls for well-planned and multifaceted approaches both to achieve an informed understanding of both residents and governments of the interactive and additive changes caused by development, and to design action agendas to influence such change at the ecological and social level.

  5. Effects of conservation practices on fishes within agricultural watersheds

    Science.gov (United States)

    Conservation practices have been regularly implemented within agricultural watersheds in the United States without documentation of their impacts. The goal of the ARS Conservation Effects Assessment Project Watershed Assessment Study is to quantify the effect of conservation practices within 14 agri...

  6. Mathematical modeling of detonation initiation via flow cumulation effects

    Science.gov (United States)

    Semenov, I.; Utkin, P.; Akhmedyanov, I.

    2016-07-01

    The paper concerns two problems connected with the idea of gaseous detonation initiation via flow cumulation effects and convergence of relatively weak shock waves (SW). The first one is the three-dimensional (3D) numerical investigation of shock-to-detonation transition (SDT) in methane-air mixture in a tube with parabolic contraction followed by the tube section of narrow diameter and conical expansion. The second problem is the numerical study of the start-up of the model small-scale hydrogen electrochemical pulse detonation engine with the use of electrical discharge generating the toroidal SW. The investigation is performed by means of numerical simulation with the use of modern high-performance computing systems.

  7. Effects of Surface Emitting and Cumulative Collisions on Elliptic Flow

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-Li; WU Feng-Juan; ZHANG Jing-Bo; TANG Gui-Xin; HUO Lei

    2008-01-01

    @@ The integral and differential elliptic flow of partons is calculated using the multiphase transport model for Au+Au collisions at centre-of-mass energy √SNN=200 GeV.It is shown that elliptic flow of partons freezing out at early time,which is affected mainly by surface emittance,decreases with time and elliptic flow of partons freezing out at late time,which is dominated by cumulative collisions,increases with time.The elliptic flow of partons freezing out early has a large contribution to the flatting of curve of final differential elliptic flow at large transverse momentum.It is argued that the effect of surface emittance is not neglectable.

  8. The cumulative effect of risk compensation on infection preventive measures.

    Science.gov (United States)

    Maxin, Daniel; Sega, Laurentiu; Eaton, Lisa

    2016-12-01

    We study several epidemic models (with and without gender structure) that incorporate risk compensation behavior in response to a lower chance of acquiring the infection as a result of preventive measures that are only partially effective. We show that the cumulative risk compensation that occurs between a high risk susceptible and infectious individual may play an important role in whether the implementation of these measures is successful in lowering the epidemic reproductive number. In addition, we show that certain levels of risk compensation may cancel the benefit of the low infection risk practiced by diagnosed infectious individuals when the goal is a reduction of the epidemic reproductive number. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. The cumulative energy effect for improved ignition timing

    Energy Technology Data Exchange (ETDEWEB)

    Markhotok, A., E-mail: amarhotk@phys.washington.edu [Physics Department, Old Dominion University, Norfolk, Virginia 23529 (United States)

    2015-04-15

    A technique capable of improving timing in ignition applications is proposed. It is based on the use of shock waves propagating in a specific medium that allows achieving extremely high speeds and energies. The model uses the energy cumulation effect in the presence of the shock wave refraction on an interface with plasma. The problem was solved analytically and the effects were demonstrated for a cylindrically symmetrical geometry. Numerical results show very quick and uneven acceleration of different portions of the shock front. Its strong distortions lead to formation of a sharply focused jet near the axis of symmetry. The ability of the shock to achieve extremely high speeds and energies can be useful in design of efficient combustors for hypersonic systems, and possibly offers an alternative way of construction of a nuclear fusion reactor. Recommendations are given in terms of adjustment parameters and can be applied at any problem scale and for various combinations of the strengths of the effects involved in the problem.

  10. Cumulative Effects of Barriers on the Movements of Forest Birds

    Directory of Open Access Journals (Sweden)

    Marc Bélisle

    2002-01-01

    Full Text Available Although there is a consensus of opinion that habitat fragmentation has deleterious effects on animal populations, primarily by inhibiting dispersal among remaining patches, there have been few explicit demonstrations of the ways by which degraded habitats actually constrain individual movement. Two impediments are primarily responsible for this paucity: it is difficult to separate the effects of habitat fragmentation (configuration from habitat loss (composition, and conventional measures of fragmented habitats are assumed to be, but probably are not, isotropic. We addressed these limitations by standardizing differences in forest cover in a clearly anisotropic configuration of habitat fragmentation by conducting a homing experiment with three species of forest birds in the Bow Valley of Banff National Park, Canada. Birds were translocated (1.2-3.5  km either parallel or perpendicular to four/five parallel barriers that are assumed to impede the cross-valley travel of forest-dependent animals. Taken together, individuals exhibited longer return times when they were translocated across these barriers, but differences among species suggest a more complex interpretation. A long-distance migrant (Yellow-rumped Warbler, Dendroica coronata behaved as predicted, but a short-distance migrant (Golden-crowned Kinglet, Regulus satrapa was indifferent to barrier configuration. A resident (Red-breasted Nuthatch, Sitta canadensis exhibited longer return times when it was translocated parallel to the barriers. Our results suggest that an anisotropic arrangement of small, open areas in fragmented landscapes can have a cumulative barrier effect on the movement of forest animals, but that both modelers and managers will have to acknowledge potentially counterintuitive differences among species to predict the effect that these may have on individual movement and, ultimately, dispersal.

  11. Cumulative effects of planned industrial development and climate change on marine ecosystems

    Directory of Open Access Journals (Sweden)

    Cathryn Clarke Murray

    2015-07-01

    Full Text Available With increasing human population, large scale climate changes, and the interaction of multiple stressors, understanding cumulative effects on marine ecosystems is increasingly important. Two major drivers of change in coastal and marine ecosystems are industrial developments with acute impacts on local ecosystems, and global climate change stressors with widespread impacts. We conducted a cumulative effects mapping analysis of the marine waters of British Columbia, Canada, under different scenarios: climate change and planned developments. At the coast-wide scale, climate change drove the largest change in cumulative effects with both widespread impacts and high vulnerability scores. Where the impacts of planned developments occur, planned industrial and pipeline activities had high cumulative effects, but the footprint of these effects was comparatively localized. Nearshore habitats were at greatest risk from planned industrial and pipeline activities; in particular, the impacts of planned pipelines on rocky intertidal habitats were predicted to cause the highest change in cumulative effects. This method of incorporating planned industrial development in cumulative effects mapping allows explicit comparison of different scenarios with the potential to be used in environmental impact assessments at various scales. Its use allows resource managers to consider cumulative effect hotspots when making decisions regarding industrial developments and avoid unacceptable cumulative effects. Management needs to consider both global and local stressors in managing marine ecosystems for the protection of biodiversity and the provisioning of ecosystem services.

  12. 43 CFR 46.115 - Consideration of past actions in the analysis of cumulative effects.

    Science.gov (United States)

    2010-10-01

    ... Environmental Quality § 46.115 Consideration of past actions in the analysis of cumulative effects. When... Memorandum on Consideration of Past Actions in Cumulative Effects Analysis” dated June 24, 2005, or any... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Consideration of past actions in...

  13. 14 CFR Section 18 - Objective Classification-Cumulative Effect of Changes in Accounting Principles

    Science.gov (United States)

    2010-01-01

    ... of Changes in Accounting Principles Section 18 Section 18 Aeronautics and Space OFFICE OF THE... Objective Classification—Cumulative Effect of Changes in Accounting Principles 98Cumulative Effect of Changes in Accounting Principles. Record here the difference between the amount of retained earnings...

  14. Effective Carrier Sensing in CSMA Networks under Cumulative Interference

    CERN Document Server

    Fu, Liqun; Huang, Jianwei

    2009-01-01

    This paper proposes and investigates the concept of a safe carrier-sensing range that can guarantee interference safe (also termed hidden-node-free) transmissions in CSMA networks under the cumulative interference model. Compared with the safe carrier-sensing range under the commonly assumed but less realistic pairwise interference model, we show that the safe carrier-sensing range required under the cumulative interference model is larger by a constant multiplicative factor. The concept of a safe carrier-sensing range, although amenable to elegant analytical results, is inherently not compatible with the conventional power threshold carrier-sensing mechanism (e.g., that used in IEEE 802.11). Specifically, the absolute power sensed by a node in the conventional mechanism does not contain enough information for it to derive its distances from other concurrent transmitter nodes. We show that, fortunately, a carrier-sensing mechanism called Incremental-Power Carrier-Sensing (IPCS) can realize the carrier-sensing...

  15. [Cumulative effect of Coriolis acceleration on coronary hemodynamics].

    Science.gov (United States)

    Lapaev, E V; Bednenko, V S

    1985-01-01

    Time-course variations in coronary circulation and cardiac output were measured in 29 healthy test subjects who performed tests with a continuous cumulation of Coriolis accelerations and in 12 healthy test subjects who were exposed to Coriolis accelerations combined with acute hypoxia. Adaptive changes in coronary circulation were seen. It is recommended to monitor coronary circulation during vestibulometric tests as part of medical expertise of the flying personnel.

  16. Radiologic imaging in cystic fibrosis: cumulative effective dose and changing trends over 2 decades.

    LENUS (Irish Health Repository)

    O'Connell, Oisin J

    2012-06-01

    With the increasing life expectancy for patients with cystic fibrosis (CF), and a known predisposition to certain cancers, cumulative radiation exposure from radiologic imaging is of increasing significance. This study explores the estimated cumulative effective radiation dose over a 17-year period from radiologic procedures and changing trends of imaging modalities over this period.

  17. The effects of antipoverty programs on children's cumulative level of poverty-related risk.

    Science.gov (United States)

    Gassman-Pines, Anna; Yoshikawa, Hirokazu

    2006-11-01

    The authors examined the effects of antipoverty programs on children's cumulative poverty-related risk and the relationship between cumulative poverty-related risk and child outcomes among low-income families. Samples included 419 children ages 3-10 years in the New Hope program and 759 children ages 2-9 years in the Minnesota Family Investment Program (MFIP), which tested 2 program approaches. Nine poverty-related risks made up the measure of cumulative risk. Both MFIP program approaches reduced cumulative poverty-related risk. New Hope reduced cumulative poverty-related risk among long-term welfare recipients. In both New Hope and MFIP, significant linear relationships between cumulative poverty-related risk and parent-reported behavior problems and school achievement were found. Cumulative poverty-related risk partially mediated the impacts of the MFIP programs on children's behavior problems. Among long-term welfare recipients, cumulative poverty-related risk partially mediated New Hope's impact on parent-reported school achievement.

  18. Deliberative Democracy, Institution Building, and the Pragmatics of Cumulative Effects Assessment

    Directory of Open Access Journals (Sweden)

    John R. Parkins

    2011-09-01

    Full Text Available Cumulative effects assessment is a process of scientific analysis, social choice, and public policy development, yet the linkages among these domains are often less than transparent. Limits to scientific and technical assessment, issues of power and control of information, and episodic forms of civic engagement represent serious challenges to meaningful understanding of cumulative effects assessment and land-use planning. In articulating these challenges, I draw on case studies from Ontario's Lands for Life and Alberta's Land-use Framework to illustrate current limitations to cumulative effects assessment on public lands in Canada. As a partial remedy for these limitations, insights into a pragmatic approach to impact assessment, in contrast to decisionistic and technocratic approaches, offer a way forward through a more robust integration of scientific information, civic engagement, and public policy development. I also identify a need for longer-standing institutions that are dedicated to regional planning and cumulative effects assessment in Canada.

  19. Watershed land use effects on lake water quality in Denmark

    DEFF Research Database (Denmark)

    Nielsen, Anders; Trolle, Dennis; Søndergaard, Martin

    2012-01-01

    in the watershed. When examining the effect of different near-freshwater land zones in contrast to the entire watershed, relationships generally improved with size of zone (25, 50, 100, 200, and 400 m from the edge of lake and streams) but were by far strongest using the entire watershed. The proportion......Mitigating nutrient losses from anthropogenic nonpoint sources is today of particular importance for improving the water quality of numerous freshwater lakes worldwide. Several empirical relationships between land use and in-lake water quality variables have been developed, but they are often weak......, which can in part be attributed to lack of detailed information about land use activities or point sources. We examined a comprehensive data set comprising land use data, point-source information, and in-lake water quality for 414 Danish lakes. By excluding point-source-influenced lakes (n = 210...

  20. Mapping cumulative environmental effects, social vulnerability, and health in the San Joaquin Valley, California.

    Science.gov (United States)

    Huang, Ganlin; London, Jonathan

    2012-05-01

    To understand the social distribution of environmental hazards, methods to assess cumulative effects and their health implications are needed. We developed a cumulative environmental hazard index integrating environmental data on pollution sites, air quality, and pesticide use; a social vulnerability index to measure residents' resources to prevent or mitigate health effects; and a health index. We found that communities in California's San Joaquin Valley with high social vulnerability face more environmental burdens and have worse health conditions.

  1. The Challenge of Developing Social Indicators for Cumulative Effects Assessment and Land Use Planning

    Directory of Open Access Journals (Sweden)

    John R. Parkins

    2011-06-01

    Full Text Available This paper provides a synopsis on social indicators as relevant to cumulative effects assessment and land use planning. Although much has been done to better understand the social dimensions of environmental assessment, empirical work has been lacking on social indicators that could be used either as measurable inputs or outputs for cumulative effects assessment and land use planning in different kinds of communities and regions. Cumulative effects models currently in practice often fail to address deeper issues of community and regional well-being. Against this gap, social scientists are being asked to make reliable generalizations about functional, measurable relationships between certain social indicators and land use change or scenarios. To address this challenge, the Alberta Research Council held a two-day workshop in 2005 with social scientists. The workshop resulted in a list of prioritized social indicators that could be included in cumulative effects modeling/assessments and land use planning. The top five social indicators included population growth rate, education attainment, self-assessed quality of life, equity, i.e., distribution of benefits, and locus of control. Although consensus on social indicators and social thresholds for cumulative effects models was not reached, the insight gained from the workshop will help inform future cumulative effects assessment and land use planning.

  2. Valuing the effects of hydropower development on watershed ecosystem services: Case studies in the Jiulong River Watershed, Fujian Province, China

    Science.gov (United States)

    Wang, Guihua; Fang, Qinhua; Zhang, Luoping; Chen, Weiqi; Chen, Zhenming; Hong, Huasheng

    2010-02-01

    Hydropower development brings many negative impacts on watershed ecosystems which are not fully integrated into current decision-making largely because in practice few accept the cost and benefit beyond market. In this paper, a framework was proposed to valuate the effects on watershed ecosystem services caused by hydropower development. Watershed ecosystem services were classified into four categories of provisioning, regulating, cultural and supporting services; then effects on watershed ecosystem services caused by hydropower development were identified to 21 indicators. Thereafter various evaluation techniques including the market value method, opportunity cost approach, project restoration method, travel cost method, and contingent valuation method were determined and the models were developed to valuate these indicators reflecting specific watershed ecosystem services. This approach was applied to three representative hydropower projects (Daguan, Xizaikou and Tiangong) of Jiulong River Watershed in southeast China. It was concluded that for hydropower development: (1) the value ratio of negative impacts to positive benefits ranges from 64.09% to 91.18%, indicating that the negative impacts of hydropower development should be critically studied during its environmental administration process; (2) the biodiversity loss and water quality degradation (together accounting for 80-94%) are the major negative impacts on watershed ecosystem services; (3) the average environmental cost per unit of electricity is up to 0.206 Yuan/kW h, which is about three quarters of its on-grid power tariff; and (4) the current water resource fee accounts for only about 4% of its negative impacts value, therefore a new compensatory method by paying for ecosystem services is necessary for sustainable hydropower development. These findings provide a clear picture of both positive and negative effects of hydropower development for decision-makers in the monetary term, and also provide a

  3. Assessing the cumulative environmental effects of marine renewable energy developments: Establishing common ground.

    Science.gov (United States)

    Willsteed, Edward; Gill, Andrew B; Birchenough, Silvana N R; Jude, Simon

    2017-01-15

    Assessing and managing the cumulative impacts of human activities on the environment remains a major challenge to sustainable development. This challenge is highlighted by the worldwide expansion of marine renewable energy developments (MREDs) in areas already subject to multiple activities and climate change. Cumulative effects assessments in theory provide decision makers with adequate information about how the environment will respond to the incremental effects of licensed activities and are a legal requirement in many nations. In practise, however, such assessments are beset by uncertainties resulting in substantial delays during the licensing process that reduce MRED investor confidence and limit progress towards meeting climate change targets. In light of these targets and ambitions to manage the marine environment sustainably, reducing the uncertainty surrounding MRED effects and cumulative effects assessment are timely and vital. This review investigates the origins and evolution of cumulative effects assessment to identify why the multitude of approaches and pertinent research have emerged, and discusses key considerations and challenges relevant to assessing the cumulative effects of MREDs and other activities on ecosystems. The review recommends a shift away from the current reliance on disparate environmental impact assessments and limited strategic environmental assessments, and a move towards establishing a common system of coordinated data and research relative to ecologically meaningful areas, focussed on the needs of decision makers tasked with protecting and conserving marine ecosystems and services.

  4. Effects of urbanization on groundwater evolution in an urbanizing watershed

    Science.gov (United States)

    Reyes, D.; Banner, J. L.; Bendik, N.

    2011-12-01

    The Jollyville Plateau Salamander (Eurycea tonkawae), a candidate species for listing under the Endangered Species Act, is endemic to springs and caves within the Bull Creek Watershed of Austin, Texas. Rapid urbanization endangers known populations of this salamander. Conservation strategies lack information on the extent of groundwater contamination from anthropogenic sources in this karst watershed. Spring water was analyzed for strontium (Sr) isotopes and major ions from sites classified as "urban" or "rural" based on impervious cover estimates. Previous studies have shown that the 87Sr/86Sr value of municipal water is significantly higher than values for natural streamwater, which are similar to those for the Cretaceous limestone bedrock of the region's watersheds. We investigate the application of this relationship to understanding the effects of urbanization on groundwater quality. The use of Sr isotopes as hydrochemical tracers is complemented by major ion concentrations, specifically the dominant ions in natural groundwater (Ca and HCO3) and the ions associated with the addition of wastewater (Na and Cl). To identify high priority salamander-inhabited springs for water quality remediation, we explore the processes controlling the chemical evolution of groundwater such as municipal water inputs, groundwater-soil interactions, and solution/dissolution reactions. 87Sr/86Sr values for water samples from within the watershed range from 0.70760 to 0.70875, the highest values corresponding to sites located in the urbanized areas of the watershed. Analyses of the covariation of Sr isotopes with major ion concentrations help elucidate controls on spring water evolution. Springs located in rural portions of the watershed have low 87Sr/86Sr, high concentrations of Ca and HCO3, and low concentrations of Na and Cl. This is consistent with small inputs of municipal water. Three springs located in urban portions of the watershed have high 87Sr/86Sr, low Ca and HCO3, and

  5. Cumulative effects in inflation with ultra-light entropy modes

    Science.gov (United States)

    Achúcarro, Ana; Atal, Vicente; Germani, Cristiano; Palma, Gonzalo A.

    2017-02-01

    In multi-field inflation one or more non-adiabatic modes may become light, potentially inducing large levels of isocurvature perturbations in the cosmic microwave background. If in addition these light modes are coupled to the adiabatic mode, they influence its evolution on super horizon scales. Here we consider the case in which a non-adiabatic mode becomes approximately massless (``ultralight") while still coupled to the adiabatic mode, a typical situation that arises with pseudo-Nambu-Goldstone bosons or moduli. This ultralight mode freezes on super-horizon scales and acts as a constant source for the curvature perturbation, making it grow linearly in time and effectively suppressing the isocurvature component. We identify a Stückelberg-like emergent shift symmetry that underlies this behavior. As inflation lasts for many e-folds, the integrated effect of this source enhances the power spectrum of the adiabatic mode, while keeping the non-adiabatic spectrum approximately untouched. In this case, towards the end of inflation all the fluctuations, adiabatic and non-adiabatic, are dominated by a single degree of freedom.

  6. Investigating the effect among size, growth opportunity and cumulative abnormal returns of the companies

    Directory of Open Access Journals (Sweden)

    Khalil bevali behbahani

    2016-09-01

    Full Text Available The stockholders and investors require identifying main variables that explain stock return. Being aware of variables and achieving an appropriate model can lead to improve their investment and considering that each wise and economic person’s goal is obtain high and more returns, the current research is sought to investigate the effect of company’s characteristics and the ratio of investment on company’s cumulative abnormal returns. Statistical sample which has been used in current research includes 256 listed companies in Tehran Stock Exchange during 2002 to 2013. Dependent variable of current research is cumulative abnormal return. The independent variables whose effects are investigated on cumulative abnormal return include company’s size, growth opportunity. The data are collected and were inserted in Excel file as information database. Testing hypotheses also has been done from multi-variable regression models based on combined data technique using econometric software Eviews. The findings of the research show that there is a positive and significant relationship between company’s size and company’s cumulative abnormal return. There is also a negative and significant relationship between growth opportunities and company’s cumulative abnormal return.

  7. The effect of cultural interaction on cumulative cultural evolution.

    Science.gov (United States)

    Nakahashi, Wataru

    2014-07-07

    Cultural transmission and cultural evolution are important for animals, especially for humans. I developed a new analytical model of cultural evolution, in which each newborn learns cultural traits from multiple individuals (exemplars) in parental generation, individually explores around learned cultural traits, judges the utility of known cultural traits, and adopts a mature cultural trait. Cultural evolutionary speed increases when individuals explore a wider range of cultural traits, accurately judge the skill level of cultural traits (strong direct bias), do not strongly conform to the population mean, increase the exploration range according to the variety of socially learned cultural traits (condition dependent exploration), and make smaller errors in social learning. Number of exemplars, population size, similarity of cultural traits between exemplars, and one-to-many transmission have little effect on cultural evolutionary speed. I also investigated how cultural interaction between two populations with different mean skill levels affects their cultural evolution. A population sometimes increases in skill level more if it encounters a less skilled population than if it does not encounter anyone. A less skilled population sometimes exceeds a more skilled population in skill level by cultural interaction between both populations. The appropriateness of this analytical method is confirmed by individual-based simulations.

  8. Cumulative effects in inflation with ultra-light entropy modes

    CERN Document Server

    Achúcarro, Ana; Germani, Cristiano; Palma, Gonzalo A

    2016-01-01

    In multi-field inflation one or more non-adiabatic modes may become light, potentially inducing large levels of isocurvature perturbations in the cosmic microwave background. If in addition these light modes are coupled to the adiabatic mode, they influence its evolution on super horizon scales. Here we consider the case in which a non-adiabatic mode becomes approximately massless ("ultralight") while still coupled to the adiabatic mode, a typical situation that arises with pseudo-Nambu-Goldstone bosons or moduli. This ultralight mode freezes on super-horizon scales and acts as a constant source for the curvature perturbation, making it grow linearly in time. We identify a St\\"uckelberg-like emergent shift symmetry that underlies this behavior. As inflation lasts for many e-folds, the integrated effect of this source enhances the power spectrum of the adiabatic mode, while keeping the non-adiabatic spectrum approximately untouched. In this case, towards the end of inflation all the fluctuations, adiabatic and...

  9. Effects of multiple context and cumulative stress on urban children's adjustment in elementary school.

    Science.gov (United States)

    Morales, Julie R; Guerra, Nancy G

    2006-01-01

    Using longitudinal data collected over 2 years on a sample of 2,745 urban elementary school children (1st-6th graders, ages 6-11 years) from economically disadvantaged communities, effects of stressful experiences within 3 contexts (school, family, neighborhood), cumulative stress, and multiple context stress on 3 indices of children's adjustment (achievement, depression, and aggression) were examined. All 3 stressor contexts were related contemporaneously and longitudinally to negative outcomes across adjustment measures, with differential paths in each predictive model. Cumulative stress was linearly related to increases in adjustment problems but multiple context stress was not related to problematic adjustment beyond effects of cumulative stress alone. The important influence of life events stress on children's adjustment in disadvantaged communities is discussed.

  10. Cumulative Effects of Exposure to Violence on Posttraumatic Stress in Palestinian and Israeli Youth

    Science.gov (United States)

    Dubow, Eric F.; Boxer, Paul; Huesmann, L. Rowell; Landau, Simha; Dvir, Shira; Shikaki, Khalil; Ginges, Jeremy

    2012-01-01

    We examine cumulative and prospective effects of exposure to conflict and violence across four contexts (ethnic-political, community, family, school) on posttraumatic stress (PTS) symptoms in Palestinian and Israeli youth. Interviews were conducted with 600 Palestinian and 901 Israeli (Jewish and Arab) children (ages 8, 11, and 14) and their…

  11. Effects of Multiple Context and Cumulative Stress on Urban Children's Adjustment in Elementary School

    Science.gov (United States)

    Morales, Julie R.; Guerra, Nancy G.

    2006-01-01

    Using longitudinal data collected over 2 years on a sample of 2,745 urban elementary school children (1st-6th graders, ages 6-11 years) from economically disadvantaged communities, effects of stressful experiences within 3 contexts (school, family, neighborhood), cumulative stress, and multiple context stress on 3 indices of children's adjustment…

  12. Separate and Cumulative Effects of Adverse Childhood Experiences in Predicting Adult Health and Health Care Utilization

    Science.gov (United States)

    Chartier, Mariette J.; Walker, John R.; Naimark, Barbara

    2010-01-01

    Objectives: Objectives of this population-based study were: (1) to examine the relative contribution of childhood abuse and other adverse childhood experiences to poor adult health and increased health care utilization and (2) to examine the cumulative effects of adverse childhood experiences on adult health and health care utilization. Methods:…

  13. Effect of cumulative strain on texture characteristics during wire drawing of eutectoid steels

    Energy Technology Data Exchange (ETDEWEB)

    Yang, F. [Jiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering, Southeast University, NanJing, 211189 (China)], E-mail: yangfan.hit@gmail.com; Ma, C.; Jiang, J.Q. [Jiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering, Southeast University, NanJing, 211189 (China); Feng, H.P.; Zhai, S.Y. [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China)

    2008-10-15

    The texture characteristics associated with plastic deformation of Fe-C steels near-eutectoid composition during a continuous cold drawing process were thoroughly investigated by orientation distribution function analysis based on X-ray diffraction. The effect of cumulative drawing strains on the <1 1 0> fiber texture in drawn hypereutectoid and hypoeutectoid steel wires was discussed.

  14. Separate and Cumulative Effects of Adverse Childhood Experiences in Predicting Adult Health and Health Care Utilization

    Science.gov (United States)

    Chartier, Mariette J.; Walker, John R.; Naimark, Barbara

    2010-01-01

    Objectives: Objectives of this population-based study were: (1) to examine the relative contribution of childhood abuse and other adverse childhood experiences to poor adult health and increased health care utilization and (2) to examine the cumulative effects of adverse childhood experiences on adult health and health care utilization. Methods:…

  15. Watershed Planning within a Quantitative Scenario Analysis Framework.

    Science.gov (United States)

    Merriam, Eric R; Petty, J Todd; Strager, Michael P

    2016-07-24

    There is a critical need for tools and methodologies capable of managing aquatic systems within heavily impacted watersheds. Current efforts often fall short as a result of an inability to quantify and predict complex cumulative effects of current and future land use scenarios at relevant spatial scales. The goal of this manuscript is to provide methods for conducting a targeted watershed assessment that enables resource managers to produce landscape-based cumulative effects models for use within a scenario analysis management framework. Sites are first selected for inclusion within the watershed assessment by identifying sites that fall along independent gradients and combinations of known stressors. Field and laboratory techniques are then used to obtain data on the physical, chemical, and biological effects of multiple land use activities. Multiple linear regression analysis is then used to produce landscape-based cumulative effects models for predicting aquatic conditions. Lastly, methods for incorporating cumulative effects models within a scenario analysis framework for guiding management and regulatory decisions (e.g., permitting and mitigation) within actively developing watersheds are discussed and demonstrated for 2 sub-watersheds within the mountaintop mining region of central Appalachia. The watershed assessment and management approach provided herein enables resource managers to facilitate economic and development activity while protecting aquatic resources and producing opportunity for net ecological benefits through targeted remediation.

  16. Assessing cumulative watershed stressors: Using LIDAR to assess the amount of open lands and young forest associated with in-channel erosion for North Shore tributaries

    Science.gov (United States)

    Hydrologists with the US Forest Service have demonstrated the cumulative impacts of land use change, particularly additional open lands and young forest (< 15 yrs) on bank full flows and in-channel erosion. Mapping these impacts has been difficult due to challenges associated ...

  17. Effects of different scale land cover maps in watershed modelling

    Science.gov (United States)

    Nunes, Antonio; Araújo, Antonio; Alexandridis, Thomas; Chambel, Pedro

    2013-04-01

    Water management is a rather complex process that usually involves multiple stakeholder, multiple data and sources, and complex mathematical modelling. One of the key data sets to understand a particular water system is the characterization of the land cover. Land cover maps are essential for the estimation of environmental variables (e.g. LAI, ETa) related to water quantity. Also, land cover maps are used for modelling the water quality. For instance, watersheds that have intensive agriculture can have poor water quality due to increase of nutrients loading; forest fires have a significant negative impact over the water quality by increasing the sediment loads; forest fires can increase flood risks. The land cover dynamics can as well severely affect the water quantity and quality in watersheds. In the MyWater project we are conducting a study to supply water quantity and quality information services for five study areas in five different countries (Brazil, Greece, Mozambique, Netherlands, and Portugal). In this project several land cover maps were produced both at regional and local scales, based on the exploitation of medium and high resolution satellite images (MERIS and SPOT 4). These maps were produced through semi-automatic supervised classification procedures, using an LCCS based nomenclature of 15 classes. Validation results pointed to global accuracy values greater than 80% for all maps. In this paper we focus on studying the effect of using different scale land cover maps in the watershed modelling and its impact in results. The work presented is part of the FP7-EU project "Merging hydrological models and Earth observation data for reliable information on water - MyWater".

  18. CEAMF study, volume 2 : cumulative effects indicators, thresholds, and case studies : final

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-03-01

    The four types of cumulative effects on the environment are: alteration, loss, and fragmentation of habitat; disturbance; barriers to movement; and direct and indirect mortality. Defining where and how human activities can be continued without irreversible net harm to the environment is part of cumulative effects management. Various land-use and habitat indicators were tested in the Blueberry and Sukunka study areas of British Columbia, to address the environmental effects associated with oil and gas development. As recommended, a tiered threshold approach was used to allow for flexibility in different land management regimes and ecological settings. Success will depend on defining acceptable change, threshold values, standard public database, standard processes to calculate indicator values using the database, and project-specific and cooperative management actions. A pilot study was suggested to test the candidate thresholds and implementation process. The two areas proposed for consideration were the Jedney Enhanced Resource Development Resource Management Zone in the Fort St. John Forest District, and the Etsho Enhanced Resource Development Resource Management Zone in the Fort Nelson Forest District. Both are of interest to the petroleum and forest sectors, and support the woodland caribou, a species which is extremely sensitive to cumulative effects of habitat fragmentation and disturbance. 117 refs., 11 tabs., 39 figs.

  19. Cumulative and Synergistic Effects of Physical, Biological, and Acoustic Signals on Marine Mammal Habitat Use

    Science.gov (United States)

    2013-10-28

    seasonal breakup of the ice has begun. The bowhead whales detections finally disappear as these mammals begin their annual migration to the Arctic Ocean...Final Report Cumulative and Synergistic Effects of Physical, Biological, and Acoustic Signals on Marine Mammal Habitat Use Jeffrey A Nystuen...signals impact marine mammal habitat use. This is especially critical in areas like the Bering Sea where global climate change can lead to rapid changes

  20. Cumulative (DisAdvantage and the Matthew Effect in Life-Course Analysis.

    Directory of Open Access Journals (Sweden)

    Miia Bask

    Full Text Available To foster a deeper understanding of the mechanisms behind inequality in society, it is crucial to work with well-defined concepts associated with such mechanisms. The aim of this paper is to define cumulative (disadvantage and the Matthew effect. We argue that cumulative (disadvantage is an intra-individual micro-level phenomenon, that the Matthew effect is an inter-individual macro-level phenomenon and that an appropriate measure of the Matthew effect focuses on the mechanism or dynamic process that generates inequality. The Matthew mechanism is, therefore, a better name for the phenomenon, where we provide a novel measure of the mechanism, including a proof-of-principle analysis using disposable personal income data. Finally, because socio-economic theory should be able to explain cumulative (disadvantage and the Matthew mechanism when they are detected in data, we discuss the types of models that may explain the phenomena. We argue that interactions-based models in the literature traditions of analytical sociology and statistical mechanics serve this purpose.

  1. Cumulative effects of fecal contamination from combined sewer overflows: Management for source water protection.

    Science.gov (United States)

    Jalliffier-Verne, Isabelle; Heniche, Mourad; Madoux-Humery, Anne-Sophie; Galarneau, Martine; Servais, Pierre; Prévost, Michèle; Dorner, Sarah

    2016-06-01

    The quality of a drinking water source depends largely on upstream contaminant discharges. Sewer overflows can have a large influence on downstream drinking water intakes as they discharge untreated or partially treated wastewaters that may be contaminated with pathogens. This study focuses on the quantification of Escherichia coli discharges from combined sewer overflows (CSOs) and the dispersion and diffusion in receiving waters in order to prioritize actions for source water protection. E. coli concentrations from CSOs were estimated from monitoring data at a series of overflow structures and then applied to the 42 active overflow structures between 2009 and 2012 using a simple relationship based upon the population within the drainage network. From these estimates, a transport-dispersion model was calibrated with data from a monitoring program from both overflow structures and downstream drinking water intakes. The model was validated with 15 extreme events such as a large number of overflows (n > 8) or high concentrations at drinking water intakes. Model results demonstrated the importance of the cumulative effects of CSOs on the degradation of water quality downstream. However, permits are typically issued on a discharge point basis and do not consider cumulative effects. Source water protection plans must consider the cumulative effects of discharges and their concentrations because the simultaneous discharge of multiple overflows can lead to elevated E. coli concentrations at a drinking water intake. In addition, some CSOs have a disproportionate impact on peak concentrations at drinking water intakes. As such, it is recommended that the management of CSOs move away from frequency based permitting at the discharge point to focus on the development of comprehensive strategies to reduce cumulative and peak discharges from CSOs upstream of drinking water intakes.

  2. Cumulative risk effects in the bullying of children and young people with autism spectrum conditions.

    Science.gov (United States)

    Hebron, Judith; Oldfield, Jeremy; Humphrey, Neil

    2017-04-01

    Students with autism are more likely to be bullied than their typically developing peers. However, several studies have shown that their likelihood of being bullied increases in the context of exposure to certain risk factors (e.g. behaviour difficulties and poor peer relationships). This study explores vulnerability to bullying from a cumulative risk perspective, where the number of risks rather than their nature is considered. A total of 722 teachers and 119 parents of young people with autism spectrum conditions participated in the study. Established risk factors were summed to form a cumulative risk score in teacher and parent models. There was evidence of a cumulative risk effect in both models, suggesting that as the number of risks increased, so did exposure to bullying. A quadratic effect was found in the teacher model, indicating that there was a disproportionate increase in the likelihood of being bullied in relation to the number of risk factors to which a young person was exposed. In light of these findings, it is proposed that more attention needs to be given to the number of risks to which children and young people with autism spectrum conditions are exposed when planning interventions and providing a suitable educational environment.

  3. Cumulative Risk Assessment: An Overview of Methodological Approaches for Evaluating Combined Health Effects from Exposure to Multiple Environmental Stressors

    Science.gov (United States)

    Sexton, Ken

    2012-01-01

    Systematic evaluation of cumulative health risks from the combined effects of multiple environmental stressors is becoming a vital component of risk-based decisions aimed at protecting human populations and communities. This article briefly examines the historical development of cumulative risk assessment as an analytical tool, and discusses current approaches for evaluating cumulative health effects from exposure to both chemical mixtures and combinations of chemical and nonchemical stressors. A comparison of stressor-based and effects-based assessment methods is presented, and the potential value of focusing on viable risk management options to limit the scope of cumulative evaluations is discussed. The ultimate goal of cumulative risk assessment is to provide answers to decision-relevant questions based on organized scientific analysis; even if the answers, at least for the time being, are inexact and uncertain. PMID:22470298

  4. Effects of agroecological land use succession on soil properties in Chemoga watershed, Blue Nile basin, Ethiopia

    NARCIS (Netherlands)

    Bewket, W.; Stroosnijder, L.

    2003-01-01

    This study appraises the effects of land use on soil properties in a typical watershed in the northwestern highland of Ethiopia. Soil samples were collected from major land use types in the watershed: natural forests, cultivated lands, grazing lands and Eucalyptus plantations. The natural forests se

  5. Minnesota Watersheds

    Data.gov (United States)

    Minnesota Department of Natural Resources — Statewide minor watershed delineations with major/minor watershed identifiers and names for provinces, major watersheds, and basins. Also included are watershed...

  6. Analysis of the cumulative effect of schizophrenia-related single nucleotide polymorphisms

    Directory of Open Access Journals (Sweden)

    Lozano R

    2014-06-01

    Full Text Available Roberto Lozano,1 Reyes Marín,2 Isabel Freire,2 María-Jesús Santacruz,2 Asunción Pascual-García21Pharmacy Department, 2Psychiatry Department, Hospital Real de Nuestra Señora de Gracia, Zaragoza, SpainIt is currently believed that predisposition for schizophrenia stems from the combined effect of multiple common polymorphisms. Thus, no genetic variant is considered to be fully responsible for the disease. For this reason, analysis of the cumulative effect of schizophrenia-related single nucleotide polymorphisms (SNPs could provide information about the genetic mechanisms that underlie susceptibility.

  7. Cumulative effects of noise and odour annoyances on environmental and health related quality of life.

    Science.gov (United States)

    Oiamo, Tor H; Luginaah, Isaac N; Baxter, Jamie

    2015-12-01

    Noise and odour annoyances are important considerations in research on health effects of air pollution and traffic noise. Cumulative exposures can occur via several chemical hazards or a combination of chemical and stressor-based hazards, and related health outcomes can be generalized as manifestations of physiological and/or psychological stress responses. A major research challenge in this field is to understand the combined health effects of physiological and psychological responses to exposure. The SF-12 Health Survey is a health related quality of life (HRQoL) instrument designed for the assessment of functional mental and physical health in clinical practice and therefore well suited to research on physiological health outcomes of exposure. However, previous research has not assessed its sensitivity to psychological stress as measured by noise annoyance and odour annoyance. The current study validated and tested this application of the SF-12 Health Survey in a cross-sectional study (n = 603) that included exposure assessment for traffic noise and air pollution in Windsor, Ontario, Canada. The results indicated that SF-12 scores in Windsor were lower than Canadian normative data. A structural equation model demonstrated that this was partially due to noise and odour annoyances, which were associated with covarying exposures to ambient nitrogen dioxide and traffic noise. More specifically, noise annoyance had a significant and negative effect on both mental and physical health factors of the SF-12 and there was a significant covariance between noise annoyance and odour annoyance. The study confirmed a significant effect of psychological responses to cumulative exposures on HRQoL. The SF-12 Health Survey shows promise with respect to assessing the cumulative health effects of outdoor air pollution and traffic noise.

  8. Mismatch or cumulative stress : Toward an integrated hypothesis of programming effects

    NARCIS (Netherlands)

    Nederhof, Esther; Schmidt, Mathias V.

    2012-01-01

    This paper integrates the cumulative stress hypothesis with the mismatch hypothesis, taking into account individual differences in sensitivity to programming. According to the cumulative stress hypothesis, individuals are more likely to suffer from disease as adversity accumulates. According to the

  9. Cumulative Effects of Coastal Habitat Alterations on Fishery Resources: toward Prediction at Regional Scales

    Directory of Open Access Journals (Sweden)

    Stephen J. Jordan

    2009-06-01

    Full Text Available Coastal habitat alterations such as the loss of submersed aquatic vegetation (SAV and hardening of shorelines could have cumulative effects on valuable fishery resources. To investigate this effect, we developed a multiscale modeling framework for blue crab (Callinectes sapidus in the northern Gulf of Mexico. Areal coverage of shoreline land cover and SAV for Mobile Bay, Alabama, were combined with information from small-scale biological studies and long-term, large-scale commercial fishery data to model the potential effects of marginal habitat losses on the blue crab fishery. We applied stochastic variation in annual recruitment to the fishery to estimate probabilities for sustainable harvests under scenarios of habitat loss. The simulations suggested that, accumulated over large areas, relatively small local losses of estuarine marsh edge and SAV habitats could have long-term negative effects on the sustainability of the fishery. Spatially extensive models are required to investigate the cumulative ecological effects of many local environmental changes. The requisite scaling adds uncertainty and reduces precision, but if model parameters are accurate at each scale, accurate predictions of long-term outcomes and probabilities are possible.

  10. Cumulative effects of developed road network on woodland--a landscape approach.

    Science.gov (United States)

    Hosseini Vardei, Mahla; Salmanmahiny, Abdolrasoul; Monavari, Seyed Masoud; Kheirkhah Zarkesh, Mir Masoud

    2014-11-01

    Population growth, during the twentieth century, has increased demand for new farmlands. Accordingly, road networks have rapidly been developed to facilitate and accelerate human access to the essential resources resulted in extensive land use changes. The present study aims at assessing cumulative effects of developed road network on tree cover of Golestan Province in northern Iran. In order to detect changes over the study period of 1987-2002, the LULC map of the study area was initially prepared from the satellite images of Landsat TM (1987) and ETM+ (2002) using maximum likelihood supervised classification method. Afterwards, a total number of seven landscape matrices were selected to detect cumulative effects of the developed road network on woodland cover. The obtained results indicated that the fragile patches are mainly located at a distance of 171-342 m from the roadside. Furthermore, the majority of the patches affected by cumulative effects of development activities are situated at a distance of 342-684 m from the roadside, over an approximate area of 55 ha. The analysis of landscape metrics revealed that the developed road network has increased the landscape metrics of "the number of patches" and "patches perimeter-area ratio". It has also followed by a decrease in metrics such as "patches area", "Euclidean nearest neighbor distance", "patches proximity", "shape index", "contiguity", and "mean patches fractal dimension". The road network has also increased the "number of patches" and decreased the "mean patches area" representing further fragmentation of the landscape. With identification of highly affected wooldland cover patches, it would be possible to apply adaptive environmental management strategies to preserve and rehabilitate high-priority patches.

  11. An Effective Parameter Screening Strategy for High Dimensional Watershed Models

    Science.gov (United States)

    Khare, Y. P.; Martinez, C. J.; Munoz-Carpena, R.

    2014-12-01

    Watershed simulation models can assess the impacts of natural and anthropogenic disturbances on natural systems. These models have become important tools for tackling a range of water resources problems through their implementation in the formulation and evaluation of Best Management Practices, Total Maximum Daily Loads, and Basin Management Action Plans. For accurate applications of watershed models they need to be thoroughly evaluated through global uncertainty and sensitivity analyses (UA/SA). However, due to the high dimensionality of these models such evaluation becomes extremely time- and resource-consuming. Parameter screening, the qualitative separation of important parameters, has been suggested as an essential step before applying rigorous evaluation techniques such as the Sobol' and Fourier Amplitude Sensitivity Test (FAST) methods in the UA/SA framework. The method of elementary effects (EE) (Morris, 1991) is one of the most widely used screening methodologies. Some of the common parameter sampling strategies for EE, e.g. Optimized Trajectories [OT] (Campolongo et al., 2007) and Modified Optimized Trajectories [MOT] (Ruano et al., 2012), suffer from inconsistencies in the generated parameter distributions, infeasible sample generation time, etc. In this work, we have formulated a new parameter sampling strategy - Sampling for Uniformity (SU) - for parameter screening which is based on the principles of the uniformity of the generated parameter distributions and the spread of the parameter sample. A rigorous multi-criteria evaluation (time, distribution, spread and screening efficiency) of OT, MOT, and SU indicated that SU is superior to other sampling strategies. Comparison of the EE-based parameter importance rankings with those of Sobol' helped to quantify the qualitativeness of the EE parameter screening approach, reinforcing the fact that one should use EE only to reduce the resource burden required by FAST/Sobol' analyses but not to replace it.

  12. Simulating the Hydrologic Effects of Climate Change in 5 Research Watersheds using a Distributed-Parameter Watershed Model

    Science.gov (United States)

    Walker, J. F.; Hunt, R.; Aulenbach, B. T.; Clow, D. W.; Murphy, S.; Shanley, J. B.; Scholl, M. A.; Hay, L.; Regan, R. S.; Markstrom, S. L.

    2013-12-01

    A new focus of the U.S. Geological Survey's Water, Energy, and Biogeochemical Budgets (WEBB) program is the development of watershed models to predict hydrologic response to future conditions including land-use and climate change. Fine-scale models of 5 WEBB watersheds were constructed and embedded in coarse-scale models of larger stream systems. The WEBB watersheds range in size from 41 to 3,260 hectares; the coarse-scale models range in size from 1,100 to 4,800 square kilometers. The coarse-scale models were calibrated using data collected from 1980 to 2012 and included streamflow, snow-water equivalent (where appropriate), and seasonal distributions of solar radiation and potential evapotranspiration. Solar radiation and potential evapotranspiration were retrieved from a national gridded dataset using the USGS Geodata Portal (GDP) tool. Snowpack data was available as a national gridded dataset from December 2003 through November 2012, and was retrieved using the GDP. A stepwise approach was taken to identify specific hydrologic processes pertinent to the calibration targets. Calibration was carried out using the Parameter ESTimation (PEST) suite of automated calibration tools. Several climate models and three emission scenarios were selected from a range of Intergovernmental Panel on Climate Change (IPCC) climate projections to investigate the potential hydrologic effects of climate change in the WEBB watersheds. The GDP was used to construct input data sets for each coarse-scale model using a national dataset of downscaled climate data. Comparisons include projected changes in the dominant hydrologic processes across the five WEBB headwater basins, as well as, differences between headwater streams and higher-order streams at a regional scale.

  13. A framework for adaptive monitoring of the cumulative effects of human footprint on biodiversity.

    Science.gov (United States)

    Burton, A Cole; Huggard, David; Bayne, Erin; Schieck, Jim; Sólymos, Péter; Muhly, Tyler; Farr, Dan; Boutin, Stan

    2014-06-01

    Effective ecological monitoring is imperative in a human-dominated world, as our ability to manage functioning ecosystems will depend on understanding biodiversity responses to anthropogenic impacts. Yet, most monitoring efforts have either been narrowly focused on particular sites, species and stressors - thus inadequately considering the cumulative effects of multiple, interacting impacts at scales of management relevance - or too unfocused to provide specific guidance. We propose a cumulative effects monitoring framework that integrates multi-scaled surveillance of trends in biodiversity and land cover with targeted evaluation of hypothesized drivers of change. The framework is grounded in a flexible conceptual model and uses monitoring to generate and test empirical models that relate the status of diverse taxonomic groups to the nature and extent of human "footprint" and other landscape attributes. An adaptive cycle of standardized sampling, model development, and model evaluation provides a means to learn about the system and guide management. Additional benefits of the framework include standardized data on status and trend for a wide variety of biodiversity elements, spatially explicit models for regional planning and scenario evaluation, and identification of knowledge gaps for complementary research. We describe efforts to implement the framework in Alberta, Canada, through the Alberta Biodiversity Monitoring Institute, and identify key challenges to be addressed.

  14. Framework tool for a rapid cumulative effects assessment: case of a prominent wetland in Myanmar.

    Science.gov (United States)

    Pradhan, N; Habib, H; Venkatappa, M; Ebbers, T; Duboz, R; Shipin, O

    2015-06-01

    The wetland of focus, Inle Lake, located in central Myanmar, is well known for its unique biodiversity and culture, as well as for ingenious floating garden agriculture. During the last decades, the lake area has seen extensive degradation in terms of water quality, erosion, deforestation, and biodiversity concomitant with a major shift to unsustainable land use. The study was conducted, with an emphasis on water quality, to analyze environmental impacts (effects) changing the ecosystem and to comprehensively evaluate the environmental state of the ecosystem through an innovative Rapid Cumulative Effects Assessment framework tool. The assessment started with a framework-forming Participatory Rural Appraisal (PRA), which quantified and prioritized impacts over space and time. Critically important impacts were assessed for "intra-inter interactions" using the loop analysis simulation. Water samples were analyzed while geographic information system (GIS) and remote sensing were used to identify water pollution hotspots. It was concluded that out of a plethora of impacts, pollution from municipal sources, sedimentation, and effects exerted by floating gardens had the most detrimental impacts, which cumulatively affected the entire ecosystem. The framework tool was designed in a broad sense with a reference to highly needed assessments of poorly studied wetlands where degradation is evident, but scarcely quantified, and where long-term field studies are fraught with security issues and resource unavailability (post-conflict, poor and remote regions, e.g., Afghanistan, Laos, Sudan, etc.).

  15. CUMULATIVE EFFECTS OF DIFFERENT CULTIVATING PATTERNS ON PROPERTIES OF ALBIC SOIL IN SANJIANG PLAIN

    Institute of Scientific and Technical Information of China (English)

    YUAN Zhao-hua; LU Xian-guo; ZHOU Jia

    2006-01-01

    This paper studied the cumulative effects of different cultivating patterns on the properties of albic soils in the Sanjiang Plain using correlation analysis. The results showed that the physical and chemical properties of the albic soil changed greatly when it was cultivated as farmland. As for physical properties of the soil, bulk density and specific gravity increased gradually, the porosity and field capacity decreased gradually year by year, but they increased after being abandoned. As for chemical properties, pH increased, organic matter and other nutrients decreased with increasing of the cultivating years. For the albic soil cultivated with forage, the cumulative effects were apparently strengthened with the increase of cultivating years, especially for the bulk density, total porosity, capillary porosity and capillary moisture capacity. Moreover, fertilization also had great effects on the albic soil. Applying magnetism fertilizer improved the physical properties such as bulk density, soil moisture and porosity, raised the utilization rate of nitrogen and phosphorus fertilizer. Compared with nutrient fertilizer, utilization of the magnetism fertilizer made production increase by 5.9%-13.9%. At the same time, using organic material and loosing the albic layer could improve not only the physical, chemical and biological properties of the cultivating layer, but also the ill properties of the albic layer, thus making organic carbon and heavy fraction carbon contents increase, and biological activity increase obviously.

  16. Cumulative high doses of inhaled formoterol have less systemic effects in asthmatic children 6-11 years-old than cumulative high doses of inhaled terbutaline

    DEFF Research Database (Denmark)

    Kaae, Rikke; Agertoft, Lone; Pedersen, Sören

    2004-01-01

    OBJECTIVES: To evaluate high dose tolerability and relative systemic dose potency between inhaled clinically equipotent dose increments of formoterol and terbutaline in children. METHODS: Twenty boys and girls (6-11 years-old) with asthma and normal ECGs were studied. Ten doses of formoterol (Oxis......) 4.5 microg (F4.5) or terbutaline (Bricanyl) 500 microg (T500) were inhaled cumulatively via a dry powder inhaler (Turbuhaler) over 1 h (three patients) or 2.5 h (17 patients) and compared to a day of no treatment, in a randomised, double-blind (active treatments only), crossover trial. Blood...... pressure (BP), ECG, plasma potassium, glucose, lactate, and adverse events were monitored up to 10 h to assess tolerability and relative systemic dose potency. RESULTS: Formoterol and terbutaline had significant beta2-adrenergic effects on most outcomes. Apart from the effect on systolic BP, QRS duration...

  17. Cumulative effects, creeping enclosure, and the marine commons of New Jersey

    Directory of Open Access Journals (Sweden)

    Grant Murray

    2010-02-01

    Full Text Available In response to declining fish stocks and increased societal concern, the marine ‘commons’ of New Jersey is no longer freely available to commercial and recreational fisheries. We discuss the concept of ‘creeping’ enclosure in relation to New Jersey’s marine fisheries and suggest that reduced access can be a cumulative process and function of multiple events and processes and need not be the result of a single regulatory moment. We begin with a short review of the ‘expected’ effects of enclosure, including loss of flexibility, erosion of community, proletarianization of fishermen, and corporatization of the fishery. We then present some findings of our research and discuss how the signs of enclosure are visible in fisheries that do not feature explicitly privatized property or access rights. We rely on an oral history approach and the rich detail that emerges from attention to the lived experiences of fish harvesters to provide a framework for understanding the range of cumulative effects that have resulted from this process of creeping enclosure. We conclude with a discussion of how the gradual process of enclosure has affected the flows of information between the bio-physical environment and fish harvesters, managers and scientists by reducing both participation in fisheries and the accumulation of knowledge itself.

  18. Estimating the Cumulative Ecological Effect of Local Scale Landscape Changes in South Florida

    Science.gov (United States)

    Hogan, Dianna M.; Labiosa, William; Pearlstine, Leonard; Hallac, David; Strong, David; Hearn, Paul; Bernknopf, Richard

    2012-01-01

    Ecosystem restoration in south Florida is a state and national priority centered on the Everglades wetlands. However, urban development pressures affect the restoration potential and remaining habitat functions of the natural undeveloped areas. Land use (LU) planning often focuses at the local level, but a better understanding of the cumulative effects of small projects at the landscape level is needed to support ecosystem restoration and preservation. The South Florida Ecosystem Portfolio Model (SFL EPM) is a regional LU planning tool developed to help stakeholders visualize LU scenario evaluation and improve communication about regional effects of LU decisions. One component of the SFL EPM is ecological value (EV), which is evaluated through modeled ecological criteria related to ecosystem services using metrics for (1) biodiversity potential, (2) threatened and endangered species, (3) rare and unique habitats, (4) landscape pattern and fragmentation, (5) water quality buffer potential, and (6) ecological restoration potential. In this article, we demonstrate the calculation of EV using two case studies: (1) assessing altered EV in the Biscayne Gateway area by comparing 2004 LU to potential LU in 2025 and 2050, and (2) the cumulative impact of adding limestone mines south of Miami. Our analyses spatially convey changing regional EV resulting from conversion of local natural and agricultural areas to urban, industrial, or extractive use. Different simulated local LU scenarios may result in different alterations in calculated regional EV. These case studies demonstrate methods that may facilitate evaluation of potential future LU patterns and incorporate EV into decision making.

  19. Cumulative effects of road de-icing salt on amphibian behavior.

    Science.gov (United States)

    Denoël, Mathieu; Bichot, Marion; Ficetola, Gentile Francesco; Delcourt, Johann; Ylieff, Marc; Kestemont, Patrick; Poncin, Pascal

    2010-08-15

    Despite growing evidence of the detrimental effect of chemical substances on organisms, limited research has focused on changes in behavioral patterns, in part due to the difficulties to obtain detailed quantitative data. Recent developments in efficient computer-based video analyses have allowed testing pesticide effects on model species such as the zebrafish. However, these new techniques have not yet been applied to amphibians and directly to conservation issues, i.e., to assess toxicological risks on threatened species. We used video-tracking analyses to test a quantitative effect of an environmental contaminant on the locomotion of amphibian tadpoles (Rana temporaria) by taking into account cumulative effects. Because recent research has demonstrated effects of de-icing salts on survival and community structure, we used sodium chloride in our experimental design (25 replicates, 4 concentrations, 4 times) to test for an effect at the scale of behavior at environmentally relevant concentrations. Analysis of 372 1-h video-tracks (5 samples/s) showed a complex action of salts on behavioral patterns with a dose and cumulative response over time. Although no effects were found on mortality or growth, the highest salt concentrations reduced the speed and movement of tadpoles in comparison with control treatments. The reduced locomotor performance could have detrimental consequences in terms of tadpoles' responses to competition and predation and may be an indicator of the low concentration effect of the contaminant. On one hand, this study demonstrates the usefulness of examining behavior to address conservation issues and understand the complex action of environmental factors and, more particularly, pollutants on organisms. On the other hand, our results highlight the need of new computerized techniques to quantitatively analyze these patterns.

  20. Behavior and finite-size effects of the sixth order cumulant in the three-dimensional Ising universality class

    Science.gov (United States)

    Pan, Xue; Chen, Li-Zhu; Wu, Yuan-Fang

    2016-09-01

    The high-order cumulants of conserved charges are suggested to be sensitive observables to search for the critical point of Quantum Chromodynamics (QCD). This has been calculated to the sixth order in experiments. Corresponding theoretical studies on the sixth order cumulant are necessary. Based on the universality of the critical behavior, we study the temperature dependence of the sixth order cumulant of the order parameter using the parametric representation of the three-dimensional Ising model, which is expected to be in the same universality class as QCD. The density plot of the sign of the sixth order cumulant is shown on the temperature and external magnetic field plane. We found that at non-zero external magnetic field, when the critical point is approached from the crossover side, the sixth order cumulant has a negative valley. The width of the negative valley narrows with decreasing external field. Qualitatively, the trend is similar to the result of Monte Carlo simulation on a finite-size system. Quantitatively, the temperature of the sign change is different. Through Monte Carlo simulation of the Ising model, we calculated the sixth order cumulant of different sizes of systems. We discuss the finite-size effects on the temperature at which the cumulant changes sign. Supported by Fund Project of Sichuan Provincial Department of Education (16ZB0339), Fund Project of Chengdu Technological University for Doctor (2016RC004), Major State Basic Research Development Program of China (2014CB845402) and National Natural Science Foundation of China (11405088, 11221504)

  1. Closing the performance gap : the challenge for cumulative effects management in Alberta's Athabasca oil sands region

    Energy Technology Data Exchange (ETDEWEB)

    Kennett, S.A. [Calgary Univ., AB (Canada). Canadian Inst. of Resources Law

    2007-05-15

    This paper examined cumulative effects management strategies adopted by the Cumulative Environmental Management Association (CEMA) and the Regional Sustainable Development Strategy (RSDS), multi-stakeholder collaborations established after a set of public hearings conducted before Alberta's Energy and Utilities Board (EUB) in 1997. The initiatives were designed to examine challenges related to the management of cumulative effects of large-scale oil sands developments. However, the scale, pace, and intensity of oil sands development has now exceeded initial expectations, and concerns have been expressed over the inability of the initiatives to adequately address cumulative effects management issues. Stakeholders involved in the initiatives have also expressed doubts over the ability of the initiatives to achieve tangible results. This paper provided details of 16 interviews conducted with participants in CEMA as well as a variety of industry members, and government agencies. Respondents indicated that CEMA's performance gap was caused by the complexity of issues related to cumulative effects management, deficiencies in the initiative's organizational processes, and divergence between participants on objectives. Approaches to narrowing CEMA's performance gap must consider the rapid pace of oil sands development and the significant obstacles to cumulative effects management within legal, institutional, and policy structures. It was concluded that intense conflict around oil sands development is likely if CEMA's performance gaps are not addressed. refs.

  2. Effects of mountain tea plantations on nutrient cycling at upstream watersheds

    Science.gov (United States)

    Lin, T.-C.; Shaner, P.-J. L.; Wang, L.-J.; Shih, Y.-T.; Wang, C.-P.; Huang, G.-H.; Huang, J.-C.

    2015-11-01

    The expansion of agriculture to rugged mountains can exacerbate negative impacts of agricultural activities on ecosystem function. In this study, we monitored streamwater and rainfall chemistry of mountain watersheds at the Feitsui Reservoir Watershed in northern Taiwan to examine the effects of agriculture on watershed nutrient cycling. We found that the greater the proportion of tea plantation cover, the higher the concentrations of fertilizer-associated ions (NO3-, K+) in streamwater of the four mountain watersheds examined; on the other hand, the concentrations of the ions that are rich in soils (SO42-, Ca2+, Mg2+) did not increase with the proportion of tea plantation cover, suggesting that agriculture enriched fertilizer-associated nutrients in streamwater. Of the two watersheds for which rainfall chemistry was available, the one with higher proportion of tea plantation cover had higher concentrations of ions in rainfall and retained less nitrogen in proportion to input compared to the more pristine watershed, suggesting that agriculture can influence atmospheric deposition of nutrients and a system's ability to retain nutrients. As expected, we found that a forested watershed downstream of agricultural activities can dilute the concentrations of NO3- in streamwater by more than 70 %, indicating that such a landscape configuration helps mitigate nutrient enrichment in aquatic systems even for watersheds with steep topography. We estimated that tea plantation at our study site contributed approximately 450 kg ha-1 yr-1 of NO3-N via streamwater, an order of magnitude greater than previously reported for agricultural lands around the globe, which can only be matched by areas under intense fertilizer use. Furthermore, we constructed watershed N fluxes to show that excessive leaching of N, and additional loss to the atmosphere via volatilization and denitrification can occur under intense fertilizer use. In summary, this study demonstrated the pervasive impacts of

  3. Application of SWAT model for assessing effect on main functions of watershed ecosystem in Headwater, Thailand

    Directory of Open Access Journals (Sweden)

    W. Sudjarit

    2015-06-01

    Full Text Available The Soil and Water Assessment Tool (SWAT is a well prediction accuracy of agricultural watershed ecosystem depends on how well model input spatial parameters describe the characteristics of watershed. The aim of this study was to assess the effects on watershed ecosystem main functions in terms of water and sediment yield. It was calibrated and validated for streamflow in the watershed to evaluate alternative management scenarios and estimate their effects on watershed functions. The goodness of the calibration results was assessed by the coefficient of determination (R2. Results indicated that the average annual rainfall and streamflow estimations were quite satisfactory. On a daily scale R2 was about 0.69 and a monthly scale was 0.97 which can be considered as acceptable. However, using for the case study of an intensive agricultural watershed ecosystem, it was shown that model versions are able to appropriately reproduce the water balance, nutrients balance, carbon balance, and energy balance. Crop yield, total streamflow and total suspended sediment (TSS losses calibration were performed using field survey information and data during 2008-2012. This study showed that SWAT model was able to apply for simulating and assessing streamflow, sediment, and nutrients successfully and can be used to study the effects of land use practices on water balance, nutrient balance, carbon balance and energy balance in the small scale of sub-watershed ecosystem as well.

  4. Cumulative Effect of Racial Discrimination on the Mental Health of Ethnic Minorities in the United Kingdom.

    Science.gov (United States)

    Wallace, Stephanie; Nazroo, James; Bécares, Laia

    2016-07-01

    To examine the longitudinal association between cumulative exposure to racial discrimination and changes in the mental health of ethnic minority people. We used data from 4 waves (2009-2013) of the UK Household Longitudinal Study, a longitudinal household panel survey of approximately 40 000 households, including an ethnic minority boost sample of approximately 4000 households. Ethnic minority people who reported exposure to racial discrimination at 1 time point had 12-Item Short Form Health Survey (SF-12) mental component scores 1.93 (95% confidence interval [CI] = -3.31, -0.56) points lower than did those who reported no exposure to racial discrimination, whereas those who had been exposed to 2 or more domains of racial discrimination, at 2 different time points, had SF-12 mental component scores 8.26 (95% CI = -13.33, -3.18) points lower than did those who reported no experiences of racial discrimination. Controlling for racial discrimination and other socioeconomic factors reduced ethnic inequalities in mental health. Cumulative exposure to racial discrimination has incremental negative long-term effects on the mental health of ethnic minority people in the United Kingdom. Studies that examine exposure to racial discrimination at 1 point in time may underestimate the contribution of racism to poor health.

  5. Effect of dry spells and soil cracking on runoff generation in a semiarid micro watershed under land use change

    Science.gov (United States)

    dos Santos, Julio Cesar Neves; de Andrade, Eunice Maia; Guerreiro, Maria João Simas; Medeiros, Pedro Henrique Augusto; de Queiroz Palácio, Helba Araújo; de Araújo Neto, José Ribeiro

    2016-10-01

    Soil and water resources effective management and planning in a river basin rely on understanding of runoff generation processes, yield, and their relations to rainfall. This study analyzes the effects of antecedent soil moisture in an expansive soil and the influence of dry spells on soil cracking, runoff generation and yield in a semiarid tropical region in Brazil subject to land use change. Data were collected from 2009 to 2013 in a 2.8 ha watershed, totaling 179 natural rainfall events. In the first year of study (2009), the watershed maintained a typical dry tropical forest cover (arboreal-shrub Caatinga cover). Before the beginning of the second year of study, gamba grass (Andropogon gayanus Kunth) was cultivated after slash and burn of native vegetation. Gamba grass land use was maintained for the rest of the monitoring period. The occurrence of dry spells and the formation of cracks in the Vertisol soil were the most important factors controlling flow generation. Dry spells promoted crack formation in the expansive soil, which acted as preferential flow paths leading to high initial abstractions: average conditions for runoff to be generated included soil moisture content above 20%, rainfall above 70 mm, I30max above 60 mm h-1 and five continuous dry days at the most. The change of vegetation cover in the second year of study did not alter significantly the overall conditions for runoff initiation, showing similar cumulative flow vs. rainfall response, implying that soil conditions, such as humidity and cracks, best explain the flow generation process on the semiarid micro-scale watershed with Vertisol soil.

  6. Effects of urbanization on stream chemistry in the Croton Watershed

    Science.gov (United States)

    Lee, C. N.; Boyer, E. W.; Curry, D. S.; Hassett, J. M.

    2001-05-01

    We studied the impacts of urbanization on flow paths and water quality in the Croton Watershed, a forested area east of the Hudson River that supplies about 10% of the drinking water to residents of New York City. We focused on three small sub-catchments along an urban gradient: one that is forested and undeveloped, one that is developing a residential base, and one that is fully developed with homes. To evaluate the effects of urbanization on concentration/discharge relationships, we monitored longitudinal profiles of streamflow and chemistry (cations, anions, nutrients, pH) in each catchment under varying flow conditions. Our work shows that urbanization impacts stream chemistry in several ways: by altering flow paths of water and by providing anthropogenic sources of solutes to streamflow. The urbanized catchments had a much higher fraction of quick flow contributing to the stream than the forested catchment. Solutes associated with residential development, such as road salt and septic systems, affected stream chemistry in the developed catchments. Total dissolved solids (TDS) were highest in the urban catchment and lowest in the forested catchment. Chloride, sodium, and calcium were the largest components of TDS in the urban and developing catchments, while calcium, silica, and sulfate were the largest components of TDS in the forested catchment.

  7. Pteropods on the edge: Cumulative effects of ocean acidification, warming, and deoxygenation

    Science.gov (United States)

    Bednaršek, Nina; Harvey, Chris J.; Kaplan, Isaac C.; Feely, Richard A.; Možina, Jasna

    2016-06-01

    We review the state of knowledge of the individual and community responses of euthecosome (shelled) pteropods in the context of global environmental change. In particular, we focus on their responses to ocean acidification, in combination with ocean warming and ocean deoxygenation, as inferred from a growing body of empirical literature, and their relatively nascent place in ecosystem-scale models. Our objectives are: (1) to summarize the threats that these stressors pose to pteropod populations; (2) to demonstrate that pteropods are strong candidate indicators for cumulative effects of OA, warming, and deoxygenation in marine ecosystems; and (3) to provide insight on incorporating pteropods into population and ecosystem models, which will help inform ecosystem-based management of marine resources under future environmental regimes.

  8. Expanding the notion of researcher distress: the cumulative effects of coding.

    Science.gov (United States)

    Woodby, Lesa L; Williams, Beverly Rosa; Wittich, Angelina R; Burgio, Kathryn L

    2011-06-01

    Qualitative researchers who explore the individual's experience of health, illness, death, and dying often experience emotional stress in their work. In this article, we describe the emotional stress we experienced while coding semistructured, after-death interviews conducted with 38 next of kin of deceased veterans. Coding sensitive topic data required an unexpected level of emotional labor, the impact of which has not been addressed in the literature. In writing this discussion article, we stepped back from our roles as interviewers/coders and reflected on how our work affected us individually and as a team, and how a sequence of exposures could exert a cumulative effect for researchers in such a dual role. Through this article, we hope to generate an expanded discourse on how qualitative inquiry impacts the emotional well-being of researchers.

  9. Topographic effects on solar radiation distribution in mountainous watersheds and their influence on reference evapotranspiration estimates at watershed scale

    Directory of Open Access Journals (Sweden)

    C. Aguilar

    2010-12-01

    Full Text Available Distributed energy and water balance models require time-series surfaces of the climatological variables involved in hydrological processes. Among them, solar radiation constitutes a key variable to the circulation of water in the atmosphere. Most of the hydrological GIS-based models apply simple interpolation techniques to data measured at few weather stations disregarding topographic effects. Here, a topographic solar radiation algorithm has been included for the generation of detailed time-series solar radiation surfaces using limited data and simple methods in a mountainous watershed in southern Spain. The results show the major role of topography in local values and differences between the topographic approximation and the direct interpolation to measured data (IDW of up to +42% and −1800% in the estimated daily values. Also, the comparison of the predicted values with experimental data proves the usefulness of the algorithm for the estimation of spatially-distributed radiation values in a complex terrain, with a good fit for daily values (R2 = 0.93 and the best fits under cloudless skies at hourly time steps. Finally, evapotranspiration fields estimated through the ASCE-Penman-Monteith equation using both corrected and non-corrected radiation values address the hydrologic importance of using topographically-corrected solar radiation fields as inputs to the equation over uniform values with mean differences in the watershed of 61 mm/year and 142 mm/year of standard deviation. High speed computations in a 1300 km2 watershed in the south of Spain with up to a one-hour time scale in 30 × 30 m2 cells can be easily carried out on a desktop PC.

  10. The Scarring Effects of Bankruptcy: Cumulative Disadvantage across Credit and Labor Markets

    Science.gov (United States)

    Maroto, Michelle

    2012-01-01

    As the recent economic crisis has demonstrated, inequality often spans credit and labor markets, supporting a system of cumulative disadvantage. Using data from the National Longitudinal Survey of Youth, this research draws on stigma, cumulative disadvantage and status characteristics theories to examine whether credit and labor markets intersect…

  11. Short- and Long-Term Effects of Cumulative Finals on Student Learning

    Science.gov (United States)

    Khanna, Maya M.; Brack, Amy S. Badura; Finken, Laura L.

    2013-01-01

    In two experiments, we examined the benefits of cumulative and noncumulative finals on students' short- and long-term course material retention. In Experiment 1, we examined results from course content exams administered immediately after course finals. Course sections including cumulative finals had higher content exam scores than sections…

  12. The Scarring Effects of Bankruptcy: Cumulative Disadvantage across Credit and Labor Markets

    Science.gov (United States)

    Maroto, Michelle

    2012-01-01

    As the recent economic crisis has demonstrated, inequality often spans credit and labor markets, supporting a system of cumulative disadvantage. Using data from the National Longitudinal Survey of Youth, this research draws on stigma, cumulative disadvantage and status characteristics theories to examine whether credit and labor markets intersect…

  13. Simulated wetland conservation-restoration effects on water quantity and quality at watershed scale.

    Science.gov (United States)

    Wang, Xixi; Shang, Shiyou; Qu, Zhongyi; Liu, Tingxi; Melesse, Assefa M; Yang, Wanhong

    2010-07-01

    Wetlands are one of the most important watershed microtopographic features that affect hydrologic processes (e.g., routing) and the fate and transport of constituents (e.g., sediment and nutrients). Efforts to conserve existing wetlands and/or to restore lost wetlands require that watershed-level effects of wetlands on water quantity and water quality be quantified. Because monitoring approaches are usually cost or logistics prohibitive at watershed scale, distributed watershed models such as the Soil and Water Assessment Tool (SWAT), enhanced by the hydrologic equivalent wetland (HEW) concept developed by Wang [Wang, X., Yang, W., Melesse, A.M., 2008. Using hydrologic equivalent wetland concept within SWAT to estimate streamflow in watersheds with numerous wetlands. Trans. ASABE 51 (1), 55-72.], can be a best resort. However, there is a serious lack of information about simulated effects using this kind of integrated modeling approach. The objective of this study was to use the HEW concept in SWAT to assess effects of wetland restoration within the Broughton's Creek watershed located in southwestern Manitoba, and of wetland conservation within the upper portion of the Otter Tail River watershed located in northwestern Minnesota. The results indicated that the HEW concept allows the nonlinear functional relations between watershed processes and wetland characteristics (e.g., size and morphology) to be accurately represented in the models. The loss of the first 10-20% of the wetlands in the Minnesota study area would drastically increase the peak discharge and loadings of sediment, total phosphorus (TP), and total nitrogen (TN). On the other hand, the justifiable reductions of the peak discharge and loadings of sediment, TP, and TN in the Manitoba study area may require that 50-80% of the lost wetlands be restored. Further, the comparison between the predicted restoration and conservation effects revealed that wetland conservation seems to deserve a higher priority

  14. Depressive Symptoms in College Women: Examining the Cumulative Effect of Childhood and Adulthood Domestic Violence.

    Science.gov (United States)

    Al-Modallal, Hanan

    2016-10-01

    The purpose of this study was to examine the cumulative effect of childhood and adulthood violence on depressive symptoms in a sample of Jordanian college women. Snowball sampling technique was used to recruit the participants. The participants were heterosexual college-aged women between the ages of 18 and 25. The participants were asked about their experiences of childhood violence (including physical violence, sexual violence, psychological violence, and witnessing parental violence), partner violence (including physical partner violence and sexual partner violence), experiences of depressive symptoms, and about other demographic and familial factors as possible predictors for their complaints of depressive symptoms. Multiple linear regression analysis was implemented to identify demographic- and violence-related predictors of their complainants of depressive symptoms. Logistic regression analysis was further performed to identify possible type(s) of violence associated with the increased risk of depressive symptoms. The prevalence of depressive symptoms in this sample was 47.4%. For the violence experience, witnessing parental violence was the most common during childhood, experienced by 40 (41.2%) women, and physical partner violence was the most common in adulthood, experienced by 35 (36.1%) women. Results of logistic regression analysis indicated that experiencing two types of violence (regardless of the time of occurrence) was significant in predicting depressive symptoms (odds ratio [OR] = 3.45, p women's demographic characteristics, marital status (single vs. engaged), mothers' level of education, income, and smoking were significant in predicting depressive symptoms. Assessment of physical violence and depressive symptoms including the cumulative impact of longer periods of violence on depressive symptoms is recommended to be explored in future studies.

  15. Multiscale impacts of armoring on Salish Sea shorelines: Evidence for cumulative and threshold effects

    Science.gov (United States)

    Dethier, Megan N.; Raymond, Wendel W.; McBride, Aundrea N.; Toft, Jason D.; Cordell, Jeffery R.; Ogston, Andrea S.; Heerhartz, Sarah M.; Berry, Helen D.

    2016-06-01

    Shoreline armoring is widespread in many parts of the protected inland waters of the Pacific Northwest, U.S.A, but impacts on physical and biological features of local nearshore ecosystems have only recently begun to be documented. Armoring marine shorelines can alter natural processes at multiple spatial and temporal scales; some, such as starving the beach of sediments by blocking input from upland bluffs may take decades to become visible, while others such as placement loss of armoring construction are immediate. We quantified a range of geomorphic and biological parameters at paired, nearby armored and unarmored beaches throughout the inland waters of Washington State to test what conditions and parameters are associated with armoring. We gathered identical datasets at a total of 65 pairs of beaches: 6 in South Puget Sound, 23 in Central Puget Sound, and 36 pairs North of Puget Sound proper. At this broad scale, demonstrating differences attributable to armoring is challenging given the high natural variability in measured parameters among beaches and regions. However, we found that armoring was consistently associated with reductions in beach width, riparian vegetation, numbers of accumulated logs, and amounts and types of beach wrack and associated invertebrates. Armoring-related patterns at lower beach elevations (further vertically from armoring) were progressively harder to detect. For some parameters, such as accumulated logs, there was a distinct threshold in armoring elevation that was associated with increased impacts. This large dataset for the first time allowed us to identify cumulative impacts that appear when increasing proportions of shorelines are armored. At large spatial and temporal scales, armoring much of a sediment drift cell may result in reduction of the finer grain-size fractions on beaches, including those used by spawning forage fish. Overall we have shown that local impacts of shoreline armoring can scale-up to have cumulative and

  16. On the development of online cities and neighborhoods: an exploration of cumulative and segmentive network effects in social media

    NARCIS (Netherlands)

    Maris, I.; Huizinga, A; Bouman, W.; Tuunainen, V.K.; Rossi, M.; Nandhakumar, J.

    2011-01-01

    This paper outlines a research in progress set to study network effects in social media. The focus is on outlining the theoretical framework in which this study is embedded. The concepts of cumulative network effects and segmentive network effects are introduced to explain the processes by which

  17. On the development of online cities and neighborhoods: an exploration of cumulative and segmentive network effects in social media

    NARCIS (Netherlands)

    Maris, I.; Huizinga, A; Bouman, W.; Tuunainen, V.K.; Rossi, M.; Nandhakumar, J.

    2011-01-01

    This paper outlines a research in progress set to study network effects in social media. The focus is on outlining the theoretical framework in which this study is embedded. The concepts of cumulative network effects and segmentive network effects are introduced to explain the processes by which soc

  18. Cumulative childhood trauma and psychological maladjustment of sexually abused children in Korea: mediating effects of emotion regulation.

    Science.gov (United States)

    Choi, Ji Young; Oh, Kyung Ja

    2014-02-01

    The purpose of the present study was to identify the mediating effects of emotion regulation on the association between cumulative childhood trauma and behavior problems in sexually abused children in Korea, using structural equation modeling (SEM). Data were collected on 171 children (ages 6-13 years) referred to a public counseling center for sexual abuse in Seoul, Korea. Cumulative childhood traumas were defined on the basis of number of traumas (physical abuse, witnessing domestic violence, neglect, traumatic separation from parent, and sexual abuse) and the severity and duration of traumas. Children were evaluated by their parents on emotion regulation using the Emotion Regulation Checklist and internalizing and externalizing behavior problems using the Korean-Child Behavior Checklist. SEM analyses confirmed the complete mediation model, in which emotion dysregulation fully mediates the relationship between cumulative childhood traumas and internalizing/externalizing behavior problems. These findings indicate that emotion regulation is an important mechanism that can explain the negative effects of cumulative childhood traumas and that there is a need to focus on emotion regulation in sexually abused children exposed to cumulative trauma. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Do self-reported concussions have cumulative or enduring effects on drivers' anticipation of traffic hazards?

    Science.gov (United States)

    Preece, Megan H W; Horswill, Mark S; Ownsworth, Tamara

    2016-01-01

    To investigate the cumulative effect of multiple self-reported concussions and the enduring effect of concussion on drivers' hazard perception ability. It was hypothesized: (1) that individuals reporting multiple previous concussions would be slower to anticipate traffic hazards than individuals reporting either one previous concussion or none; and (2) that individuals reporting a concussion within the past 3 months would be slower to anticipate traffic hazards than individuals reporting either an earlier concussion or no prior concussion. Two hundred and eighty-two predominantly young drivers (nconcussed = 68, Mage = 21.57 years, SDage = 6.99 years, 66% female) completed a validated hazard perception test (HPT) and measures of emotional, cognitive, health and driving status. A one-way analysis of variance showed that there was no significant effect of concussion number on HPT response times. Similarly, pairwise comparisons showed no significant differences between the HPT response times of individuals reporting a concussion within the previous 3 months, individuals reporting an earlier concussion and the never concussed group. The findings suggest that previous concussions do not adversely affect young drivers' ability to anticipate traffic hazards; however, due to reliance on self-reports of concussion history, further prospective longitudinal research is needed.

  20. Experimental assessment of cumulative temperature and UV-B radiation effects on Mediterranean plankton metabolism

    KAUST Repository

    Garcia-Corral, Lara S.

    2015-07-07

    The Mediterranean Sea is a vulnerable region for climate change, warming at higher rates compare to the global ocean. Warming leads to increased stratification of the water column and enhanced the oligotrophic nature of the Mediterranean Sea. The oligotrophic waters are already highly transparent, however, exposure of Mediterranean plankton to ultraviolet radiation (UV-B and UV-A) may increase further if the waters become more oligotrophic, thereby, allowing a deeper UV radiation penetration and likely enhancing impacts to biota. Here we experimentally elucidate the cumulative effects of warming and natural UV-B radiation on the net community production (NCP) of plankton communities. We conducted five experiments at monthly intervals, from June to October 2013, and evaluated the responses of NCP to ambient UV-B radiation and warming (+3°C), alone and in combination, in a coastal area of the northwest Mediterranean Sea. UV-B radiation and warming lead to reduced NCP and resulted in a heterotrophic (NCP < 0) metabolic balance. Both UV-B radiation and temperature, showed a significant individual effect in NCP across treatments and time. However, their joint effect showed to be synergistic as the interaction between them (UV × Temp) was statistically significant in most of the experiments performed. Our results showed that both drivers, would affect the gas exchange of CO2−O2 from and to the atmosphere and the role of plankton communities in the Mediterranean carbon cycle.

  1. The cumulative analgesic effect of repeated electroacupuncture involves synaptic remodeling in the hippocampal CA3 region

    Institute of Scientific and Technical Information of China (English)

    Qiuling Xu; Tao Liu; Shuping Chen; Yonghui Gao; Junying Wang; Lina Qiao; Junling Liu

    2012-01-01

    In the present study, we examined the analgesic effect of repeated electroacupuncture at bilateral Zusanli (ST36) and Yanglingquan (GB34) once a day for 14 consecutive days in a rat model of chronic sciatic nerve constriction injury-induced neuropathic pain. In addition, concomitant changes in calcium/calmodulin-dependent protein kinase II expression and synaptic ultrastructure of neurons in the hippocampal CA3 region were examined. The thermal pain threshold (paw withdrawal latency) was increased significantly in both groups at 2 weeks after electroacupuncture intervention compared with 2 days of electroacupuncture. In ovariectomized rats with chronic constriction injury, the analgesic effect was significantly reduced. Electroacupuncture for 2 weeks significantly diminished the injury-induced increase in synaptic cleft width and thinning of the postsynaptic density, and it significantly suppressed the down-regulation of intracellular calcium/ calmodulin-dependent protein kinase II expression in the hippocampal CA3 region. Repeated electroacupuncture intervention had a cumulative analgesic effect on injury-induced neuropathic pain reactions, and it led to synaptic remodeling of hippocampal neurons and upregulated calcium/calmodulin-dependent protein kinase II expression in the hippocampal CA3 region.

  2. Experimental assessment of cumulative temperature and UV-B radiation effects on Mediterranean plankton metabolism

    Directory of Open Access Journals (Sweden)

    Lara S. eGarcia-Corral

    2015-07-01

    Full Text Available The Mediterranean Sea is a vulnerable region for climate change, warming at higher rates compare to the global ocean. Warming leads to increased stratification of the water column and enhanced the oligotrophic nature of the Mediterranean Sea. The oligotrophic waters are already highly transparent, however, exposure of Mediterranean plankton to ultraviolet radiation (UV-B and UV-A may increase further if the waters become more oligotrophic, thereby, allowing a deeper UV radiation penetration and likely enhancing impacts to biota.Here we experimentally elucidate the cumulative effects of warming and natural UV-B radiation on the net community production (NCP of plankton communities. We conducted five experiments at monthly intervals, from June to October 2013, and evaluated the responses of NCP to ambient UV-B radiation and warming (+3ºC, alone and in combination, in a coastal area of the northwest Mediterranean Sea. UV-B radiation and warming lead to reduced net community production and resulted in a heterotrophic (NCP<0 metabolic balance. Both UV-B radiation and temperature, showed a significant individual effect in NCP across treatments and time. However, their joint effect showed to be synergistic as the interaction between them (UV x Temp was statistically significant in most of the experiments performed. Our results showed that both drivers, would affect the gas exchange of CO2-O2 from and to the atmosphere and the role of plankton communities in the Mediterranean carbon cycle

  3. Residual, direct and cumulative effect of zinc application on wheat and rice yield under rice-wheat syst

    Directory of Open Access Journals (Sweden)

    R. Khan

    2009-05-01

    Full Text Available Zinc (Zn deficiency is prevalent particularly on calcareous soils of arid and semiarid region. A field experiment was conducted to investigate the direct, residual and cumulative effect of zinc on the yield of wheat and rice in permanent layout for two consecutive years, 2004-05 and 2005-06 at Arid Zone Research Institute D.I. Khan. Soil under study was deficient in Zn (0.8 mg kg-1. Effect of Zn on yield, Zn concentrations in leaf and soils were assessed using wheat variety Naseer-2000 and rice variety IRRI-6. Three rates of Zn, ranging from 0 to 10 kg ha-1 in soil, were applied as zinc sulphate (ZnSO4. 7H2O along with basal dose fertilization of nitrogen, phosphorus and potassium. Mature leaf and soil samples were collected at panicle initiation stage. The results showed that grain yield of wheat and rice was significantly increased by the direct application of 5 and 10 kg Zn ha-1. Highest grain yield of wheat (5467 kg ha-1 was recorded with the direct application of 10 kg Zn ha-1 while 4994 kg ha-1 was recorded with the cumulative application of 10 kg Zn ha-1 but the yield increase due to residual effect of Zn was statistically lower than the cumulative effect of Zn. Maximum paddy yield was recorded with the cumulative application ofZn followed by residual and direct applied 10 and 5 kg Zn kg ha-1, respectively. Zn concentration in soils ranged from 0.3 to 1.5 mg kg-1 in wheat and 0.24 to 2.40 mg kg-1 in rice, while in leaves it ranged from 18-48 mg kg-1 in wheat and 15-52 mg kg-1 in rice. The concentration of Zn in soil and leaves increased due to the treatments in the order; cumulative > residual > direct effect > control (without Zn. The yield attributes like 1000- grain weight, number of spikes, spike length and plant height were increased by the residual, direct and cumulative effect of Zn levels; however, the magnitude of increase was higher in cumulative effect than residual and direct effect of Zn, respectively. Under Zn-deficient soil

  4. The cumulative effects of using fine particles and cyanobacteria for rehabilitation of disturbed active sand dunes

    Science.gov (United States)

    Zaady, Eli; Katra, Itzhak; Barkai, Daniel; Knoll, Yaakov; Sarig, Shlomo

    2016-04-01

    One of the main problems in desertified lands worldwide is active wind-borne sand dunes, which lead to covering of fertile soils and agricultural fields. In regions with more than 100 mm of annual rainfall, sand dunes may be naturally stabilized by biocrusts (biological soil crusts). One of the main restraints of biocrust development is the typical lack of fine particles in sand dunes. Our study investigated the combined application of fine particles [coal fly-ash <100 micrometer] and bio-inoculant of filamentous cyanobacteria, isolated from nearby natural stabilized sand dunes, on the soil surface of active sands for increasing resistance to wind erosion. Boundary-layer wind tunnel experiments were conducted in experimental plots within a greenhouse for examining the effects of adding coal fly-ash and bio-inoculant to active sands. The biocrust development was evaluated via several physical and bio-physiological variables. In all the physical measurements and the bio-physiological variables, the treatment of "sand+inoculum+coal fly-ash" showed significant differences from the "sand-control". The combination led to the best results of surface stabilization in boundary-layer wind tunnel experiments, with the lowest sand fluxes. The filamentous cyanobacteria use the fine particles of the coal fly-ash as bridges for growing toward and adhering to the large sand particles. The cumulative effects of biocrusts and coal fly-ash enhance soil surface stabilization and may allow long-term sustainability.

  5. The effect of camera viewing angle on posture assessment repeatability and cumulative spinal loading.

    Science.gov (United States)

    Sutherland, C A; Albert, W J; Wrigley, A T; Callaghan, J P

    2007-06-01

    Video-based task analysis in the workplace is often limited by equipment location and production line arrangement, therefore making it difficult to capture the motion in a single plane. The purpose of this study was to investigate the effects of camera placement on an observer's ability to accurately assess working postures in three dimensions and the resultant influence on the reliability and repeatability of calculated cumulative loading variables. Four video cameras were placed at viewing angles of 0 degrees, 45 degrees, 60 degrees and 90 degrees to the frontal plane, enabling the simultaneous collection of views of four lifting tasks (two symmetric and two asymmetric). A total of 11 participants were trained in the use of the 3DMatch 3-D posture matching software package (developed at the University of Waterloo) and were required to analyse 16 lifting trials. Four of the participants were randomly selected to return within 72 h and repeat the analysis protocol to test intra-observer repeatability. Posture matching agreement between camera views was higher when the body segments had a minimal range of motion during the task. There was no significant participant main effect; however, there was a significant (p 0.75). Joint anterior shear and joint posterior shear both provided fair to good reliability (0.4 > ICC camera viewing angle on an observer's ability to match working postural exposure was found to be small.

  6. Topographic effects on solar radiation distribution in mountainous watersheds and their influence on reference evapotranspiration estimates at watershed scale

    Directory of Open Access Journals (Sweden)

    C. Aguilar

    2010-04-01

    Full Text Available Distributed energy and water balance models require time-series surfaces of the climatological variables involved in hydrological processes. Among them, solar radiation plays an important role, especially in arid environments, as it is a key variable to the circulation of water in the atmosphere. The lack of reliable data for the assessment of solar radiation has led to the use of models. Most of the hydrological GIS-based models apply simple interpolation techniques to data measured at sparse meteorological stations disregarding topographic effects. Here, a topographic solar radiation algorithm is included for the generation of detailed time-series solar radiation surfaces using limited data and relatively simple methods, in order to quantify the effects of topography on the water losses through evapotranspiration estimates in a mountainous watershed in southern Spain. First, the comparison between the topographically corrected interpolated values of daily solar radiation and those obtained by a direct spatial interpolation technique (Inverse Distance Weighed, IDW is provided. The results show the major role of topography in local values and differences of up to +60% and −90% in the estimated daily values. Besides, the results are compared to experimental data proving the usefulness of the model for the estimation of spatially distributed radiation values in complex terrain, with a good adjustment for daily values and the best fits under cloudless skies at hourly time steps. Finally, evapotranspiration fields estimated through the ASCE-Penman-Monteith equation using both corrected and non-corrected radiation values address the hydrologic importance of using topographically corrected solar radiation fields as inputs to the equation over uniform values with mean differences in the watershed of 62 mm/year and 142 mm/year of standard deviation. High speed computations in a 1300 km2 watershed in the south of Spain with up to a one

  7. CUMULATIVE EFFECTS OF COASTAL HABITAT ALTERATIONS ON FISHERY RESOURCES: TOWARD PREDICTION AT REGIONAL SCALES

    Science.gov (United States)

    The integrity of aquatic ecosystems and habitats at the land-sea interface is challeneged by several forces, ranging from plot scale destruction and disturbance, to watershed scale perturbations, to global changes in climate and human demographis. The scientific challenge is to ...

  8. Methodologies for Assessing the Cumulative Environmental Effects of Hydroelectric Development of Fish and Wildlife in the Columbia River Basin, Volume 1, Recommendations, 1987 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Stull, Elizabeth Ann

    1987-07-01

    This volume is the first of a two-part set addressing methods for assessing the cumulative effects of hydropower development on fish and wildlife in the Columbia River Basin. Species and habitats potentially affected by cumulative impacts are identified for the basin, and the most significant effects of hydropower development are presented. Then, current methods for measuring and assessing single-project effects are reviewed, followed by a review of methodologies with potential for use in assessing the cumulative effects associated with multiple projects. Finally, two new approaches for cumulative effects assessment are discussed in detail. Overall, this report identifies and reviews the concepts, factors, and methods necessary for understanding and conducting a cumulative effects assessment in the Columbia River Basin. Volume 2 will present a detailed procedural handbook for performing a cumulative assessment using the integrated tabular methodology introduced in this volume. 308 refs., 18 figs., 10 tabs.

  9. Powdery Mildew Decreases the Radial Growth of Oak Trees with Cumulative and Delayed Effects over Years

    Science.gov (United States)

    Bert, Didier; Lasnier, Jean-Baptiste; Capdevielle, Xavier; Dugravot, Aline; Desprez-Loustau, Marie-Laure

    2016-01-01

    Quercus robur and Q. petraea are major European forest tree species. They have been affected by powdery mildew caused by Erysiphe alphitoides for more than a century. This fungus is a biotrophic foliar pathogen that diverts photosynthetate from the plant for its own nutrition. We used a dendrochronological approach to investigate the effects of different levels of infection severity on the radial growth of young oak trees. Oak infection was monitored at individual tree level, at two sites in southwestern France, over a five-year period (2001–2005). Mean infection severity was almost 75% (infected leaf area) at the end of the 2001 growing season, at both sites, but only about 40% in 2002, and 8%, 5% and 2% in 2003, 2004 and 2005, respectively. Infection levels varied considerably between trees and were positively related between 2001 and 2002. Increment cores were taken from each tree to assess annual ring widths and increases in basal area. Annual radial growth was standardised to take the effect of tree size into account. Annual standardised radial growth was significantly and negatively correlated with infection severity in the same year, for both 2001 and 2002, and at both sites. The decrease in growth reached 70–90% for highly infected trees. The earlywood width was poorly correlated with infection severity, but the proportion of latewood in tree rings was lower in highly infected trees (60%) than in less heavily infected trees (85%). Infection in 2001 and 2002 was found to have a cumulative effect on radial growth in these years, together with a delayed effect detectable in 2003. Thus, even non-lethal pathogens like powdery mildew can have a significant impact on tree functioning. This impact should be taken into account in growth and yield models, to improve predictions of forest net primary production. PMID:27177029

  10. Powdery Mildew Decreases the Radial Growth of Oak Trees with Cumulative and Delayed Effects over Years.

    Directory of Open Access Journals (Sweden)

    Didier Bert

    Full Text Available Quercus robur and Q. petraea are major European forest tree species. They have been affected by powdery mildew caused by Erysiphe alphitoides for more than a century. This fungus is a biotrophic foliar pathogen that diverts photosynthetate from the plant for its own nutrition. We used a dendrochronological approach to investigate the effects of different levels of infection severity on the radial growth of young oak trees. Oak infection was monitored at individual tree level, at two sites in southwestern France, over a five-year period (2001-2005. Mean infection severity was almost 75% (infected leaf area at the end of the 2001 growing season, at both sites, but only about 40% in 2002, and 8%, 5% and 2% in 2003, 2004 and 2005, respectively. Infection levels varied considerably between trees and were positively related between 2001 and 2002. Increment cores were taken from each tree to assess annual ring widths and increases in basal area. Annual radial growth was standardised to take the effect of tree size into account. Annual standardised radial growth was significantly and negatively correlated with infection severity in the same year, for both 2001 and 2002, and at both sites. The decrease in growth reached 70-90% for highly infected trees. The earlywood width was poorly correlated with infection severity, but the proportion of latewood in tree rings was lower in highly infected trees (60% than in less heavily infected trees (85%. Infection in 2001 and 2002 was found to have a cumulative effect on radial growth in these years, together with a delayed effect detectable in 2003. Thus, even non-lethal pathogens like powdery mildew can have a significant impact on tree functioning. This impact should be taken into account in growth and yield models, to improve predictions of forest net primary production.

  11. Effects of forest vegetation on runoff and sediment transport of watershed in Loess area,west China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaoming; YU Xinxiao; WU Sihong; LIU Huifang

    2007-01-01

    This paper aims to study the effects of vegetation on runoff and sediment transport at the watershed scale,and to provide a theoretical basis for afforestation in the Loess area,in the nested Caijiachuan watershed,Jixian County,Shanxi Province of west China.Forest watersheds and farmland watersheds with similar ten'ain features were selected through cluster analysis to study their runoff and sediment transport characteristics.Results showed that compared with farmland watersheds,runoff generation time in forest watersheds was delayed remarkably,and peak flow was reduced greatly,which indicates that vegetation played an important role in holding and absorbing rainfall.Besides,with the increase of forest coverage,the runoff amount,runoff depth and runoff coefficient decreased during the rainy seasons.The runoff depth and runoff coefficient of farmland watersheds in the rainy season were 5-20-fold as much as that of forest watersheds,and runoff and sediment yield of watersheds with low forest coverage were 2.7-2.9-fold and 3-5-fold as great as those with high coverage during rainstorms,and low forest coverage had larger variation in sediment hydrograph.For the complexity and scale dependence of the influence of forest vegetation on runoff,forest hydrological functions based on regional scale or watershed scale were worthy of further studies.

  12. The Effect of a Summarization-Based Cumulative Retelling Strategy on Listening Comprehension of College Students with Visual Impairments

    Science.gov (United States)

    Tuncer, A. Tuba; Altunay, Banu

    2006-01-01

    Because students with visual impairments need auditory materials in order to access information, listening comprehension skills are important to their academic success. The present study investigated the effectiveness of summarization-based cumulative retelling strategy on the listening comprehension of four visually impaired college students. An…

  13. Cumulative Advantages and the Emergence of Social and Ethnic Inequality: Matthew Effects in Reading and Mathematics Development within Elementary Schools?

    Science.gov (United States)

    Baumert, Jurgen; Nagy, Gabriel; Lehmann, Rainer

    2012-01-01

    This article examines the development of social and ethnic disparities in academic achievement in elementary schooling. It investigated whether reading and mathematics development in 136 mixed-ability classes shows path-dependent processes of cumulative advantage (Matthew effects) from Grades 4 to 6 (Grade 4 mean age = 10.62, SD = 0.57) resulting…

  14. Cost-effective raingauge deployment and rainfall heterogeneity effect on hydrograph simulation in mountainous watersheds

    Science.gov (United States)

    Huang-Chuan, Jr.; Kao, Shuh-Ji; Chang, Kang-Tsung; Lin, Chuan-Yao; Chang, Pao-Liang

    2008-08-01

    To what extent hydrograph simulation was influenced by the representativeness of rainfall input were examined in meso-scale subtropical mountainous watersheds, accordingly, cost-effective raingauge deployment was suggested. Two nested watersheds in northern Taiwan and two extreme typhoons with torrential rains were undertaken as case studies. The input of radar rainfall estimates with high spatial resolution of 1.3 km2 served as a reference, which was applied onto hydrograph simulation in TOPMODEL. After calibration, optimal parameters were obtained and fixed to examine effect of deviated rainfall on hydrograph. To mimic possible raingauge networks we designed four raingauge number classes: very low (3 points/total pixels), low (10 points/total), medium (20 points/total), and high (50 points/total) based on radar rainfall for the two watersheds in different size, thus, creating wide spectrum of raingauge density. All the corresponding hydrographs were compared with the reference hydrograph to probe errors in event discharge induced by calculated rainfall input. Results showed that with the decreasing of raingauge density the biases (indicated by RMSE) of rainfall field estimates increase and the potential variability in rainfall field due to random sampling in raingauge location is exaggerated. By contrast, biases in model hydrographs are significantly smaller than that in rainfall field. When the raingauge governing area is <10 km2/gauge, the biased rainfall field shows no detectable effect on hydrographs. Incomparably lower RMSE in hydrograph indicates that surplus and deficit rainfalls at different locations were compensated in model simulation. In term of reliable hydrograph simulation, obviously, the criterion for raingauge density is not as high as that for rainfall estimate. When gauge governing is <20 km2/gauge, both the rainfall and discharge were successfully (±10% error) estimated in term of total volume. Accordingly, we suggested that covering area ~20

  15. Cumulative effects of rapid climate and land-use changes on the Yamal Peninsula, Russia

    Science.gov (United States)

    Walker, D. A.; Leibman, M. O.; Forbes, B. C.; Epstein, H. E.

    2008-12-01

    Our principal goal is to develop better, more far-looking tools to predict the cumulative effects of resource development, climate-change, and traditional land use. Here we use remote sensing, climate-change analyses, socio-economic analyses, and vegetation-change models to examine the cumulative effects of climate change, gas development, and reindeer herding on the Yamal Peninsula in northwest Siberia as part of the Northern Eurasia Earth Science Partnership Initiative (NEESPI). We find: 1. Direct (planned) impacts of industrial activities on the Yamal Peninsula are currently local and limited in extent, but this is changing rapidly as extensive gas fields are developed and land and sea transportation corridors are developed to get the gas to market. Indirect impacts of the development at Bovanenkovo, the largest gas field, exceed the direct impacts by a factor of three, and the total area of influence of the development on the reindeer pasturelands (e.g., area where migration routes and access to pasturelands is affected) exceeds the direct impacts by a factor of about 40. 2. The trend in land-surface temperatures has co-varied with the trend in sea-ice. Low sea ice in the preceding December-March period is correlated to warmer land temperature the following summer. The sea- ice trends in the Kara Sea-Yamal region are tied to variation in the North Atlantic Oscillation index. 4. Only a small greening response to warming has been detected on the Yamal in comparison with some other areas in the Arctic (e.g. Northern Alaska). The actual effects of climate-change on vegetation are currently hard to document at the ground level because of lack of baseline and long-term ground observations and difficulty of excluding reindeer in these studies. 5. There is high potential for extensive landscape effects due to unstable sandy soils, and extremely ice-rich permafrost near the surface on slopes. 6. Two different vegetation modeling approaches are being used to predict

  16. Indirect Effects and Potential Cumulative Impacts of Dredging in an Urbanized Estuary

    Science.gov (United States)

    Sommerfield, C. K.; Chen, J.; Ralston, D. K.; Geyer, W. R.

    2016-02-01

    For over two centuries, the Delaware River and Bay estuary has supported one of the most economically important ports in the United States. To accommodate ships of ever-increasing size, the 165-km axial shipping channel has been deepened to over twice the natural depth of the estuary. While it is known that the channel has modified tides and sedimentation patterns in the estuary, unknown are the impacts on the ecosystem as a whole. A concern is the influence of channelization on sediment movement to the tidal wetland coast, which is eroding at rates on the order of meters per year. Tidal wetlands frame the entire estuary and provide vital ecosystem services ranging from recreation to carbon sequestration. To identify shifts in baseline conditions, we are performing a retrospective analysis of estuarine dynamics using historical bathymetry, numerical modeling, and observational studies. The period of interest extends from 1848 (50 years prior to channel construction) to present. During this period the channel was progressively deepened from its natural depth of 5.5 m to the current depth of 14 m. Preliminary modeling results support independent evidence that the salt intrusion and zone of rapid sediment deposition migrated several 10s of kilometers up-estuary as an indirect effect of deepening. Ironically, the locus of intense deposition now falls squarely within the Wilmington-Philadelphia port complex; river sediment that initially settles in this area is removed by maintenance dredging before it can disperse seaward. Sediment budgetary analysis indicates that the mass of sediment dredged from the upper estuary on average exceeds the mass of the new sediment supplied from the drainage basin. Hence, a probable cumulative impact of dredging is a reduction in sediment delivery to the lower estuary and fringing wetlands. Connections among the shipping channel, wave-tide interactions, and marsh edge erosion are a topic of ongoing modeling and observational research.

  17. Spatial-temporal characteristics of the "cumulative effect" of torrential rain over South China

    Science.gov (United States)

    Chu, Qucheng; Wang, Qiguang; Qiao, Shaobo; Feng, Guolin

    2017-02-01

    To expand torrential rain, which is a meso- and microscale weather process, to a meso- and long-scale weather process, in this paper, we choose South China as a sample region and propose the conception of the "Cumulative Effect" of torrential rain (CETR) by using daily precipitation observational data from 740 stations. Through a statistical analysis of the observations, three indexes—continuous time ( L d), control area ( A r), and precipitation contribution rate ( Q s)—are used to define the CETR and indicate the torrential rain processes. The relationships between the CETR and simultaneous total precipitation over South China are analyzed in the pre-flooding and latter flooding seasons. This analysis shows that on both interannual and interdecadal scales, the three indexes are highly correlated with simultaneous total precipitation over South China in the pre-flooding season and latter flooding season. Moreover, an empirical orthogonal function (EOF) analysis is performed to classify the spatial distribution of the CETR. In both the pre-flooding season and the latter flooding season, the four major spatial models of torrential rain are similar to those of total precipitation over South China. With regard to the amount of precipitation caused by the CETR, the latter flooding season is affected more significantly than the pre-flooding season. Regarding the geographical distribution of precipitation, the opposite result occurs. In conclusion, in both the pre-flooding season and the latter flooding season, the CETR influences and even determines the amount and distribution of precipitation over South China.

  18. Fur-bearers in the field : study examines cumulative effects of activity at Chinchaga

    Energy Technology Data Exchange (ETDEWEB)

    Jaremko, D.

    2005-08-01

    The challenges facing the oil and gas industry regarding cumulative environmental impacts were discussed. This issue has become important to the oil and gas industry, particularly as communities, governments, environmental groups and investors seek better understanding of the long-term consequences of development and how its effects can be mitigated. Long-term studies and baseline data are important. For the last 8 winters, Ernst Environmental Services (EES) has conducted wildlife monitoring at Chinchaga, which straddles the border between north-Western Alberta and northeastern British Columbia (BC). The area has been described as one of the last boreal wilderness areas in the province. It also has a very rich oil field. There are now more than 140 wells, and this boom has brought along much associated infrastructure, including pipelines, winter roads and a gas plant on the BC side. Each winter, as activity increases, EES uses snow-tracking, photo documentation, remote-camera monitoring and scat collection to capture data about the effects of drilling activities. Scat is collected for stress-level analysis. Although initial studies indicate that wolverines have not been displaced by oil and gas activity, new data has shown that wolverines have returned to territories where oil and gas activity has stopped. Data continues to support the idea that activity does not displace moose, marten, lynx or fisher populations. Using this data, the EES has made several recommendations about wildlife and industry interactions, including no use of recreational vehicles; no harassment of wildlife; the restriction of engine retarder brakes in specified areas; and no idling of vehicles. Additionally, well sites should not be located in old-growth areas, all activities should stop by March 15, and workers should be educated about the consequences of their actions. Controversies concerning the EES's methods were presented. It was suggested that the inefficacy of the procedure was

  19. Effects of Cumulative Family Risk Factors on American Students' Academic Performance

    Science.gov (United States)

    Dunst, Carl J.; Hamby, Deborah W.

    2016-01-01

    The relationships between cumulative family risk factors and American students' academic performance were examined in all 50 States and the District of Columbia. Data from the 2007 "American Community Survey" were used to ascertain the percent of birth to 18 year old children in the United States who experienced three or more risk…

  20. Cumulative versus end-of-course assessment : effects on self-study time and test performance

    NARCIS (Netherlands)

    Kerdijk, Wouter; Cohen-Schotanus, Janke; Mulder, B. Florentine; Muntinghe, Friso L. H.; Tio, Rene A.

    2015-01-01

    ContextStudents tend to postpone preparation for a test until the test is imminent, which raises various risks associated with cramming' behaviours, including that for suboptimal learning. Cumulative assessment utilises spaced testing to stimulate students to study more frequently and to prevent pro

  1. Cumulative effects of early poverty on cortisol in young children: moderation by autonomic nervous system activity.

    Science.gov (United States)

    Blair, Clancy; Berry, Daniel; Mills-Koonce, Roger; Granger, Douglas

    2013-11-01

    The relation of the cumulative experience of poverty in infancy and early childhood to child cortisol at age 48 months was examined in a prospective longitudinal sample of children and families (N=1292) in predominantly low-income and rural communities in two distinct regions of the United States. Families were seen in the home for data collection and cumulative experience of poverty was indexed by parent reported income-to-need ratio and household chaos measures collected between child ages 2 months and 48 months. For the analysis presented here, three saliva samples were also collected over an approximate 90 min interval at child age 48 months and were assayed for cortisol. ECG data were also collected during a resting period and during the administration of a mildly challenging battery of cognitive tasks. Mixed model analysis indicated that child cortisol at 48 months decreased significantly over the sampling time period and that cumulative time in poverty (number of years income-to-need less than or equal to 1) and cumulative household chaos were significantly related to a flatter trajectory for cortisol change and to an overall higher level of cortisol, respectively. Findings also indicated that respiratory sinus arrhythmia derived from the ECG data moderated the association between household chaos and child cortisol and that increase in respiratory sinus arrhythmia during the cognitive task was associated with an overall lower level of cortisol at 48 months.

  2. Climate and Land Use Change Effects on Ecological Resources in Three Watersheds: A Synthesis Report (Final Report)

    Science.gov (United States)

    EPA announced the availability of the final report, Climate and Land-Use Change Effects on Ecological Resources in Three Watersheds: A Synthesis Report. This report provides a summary of climate change impacts to selected watersheds and recommendations for how to improv...

  3. The Choptank Watershed Wetland Conservation Effects Assessment Project: Monitoring the Delivery of Wetland Ecosystem Services across the Landscape

    Science.gov (United States)

    CEAP-Wetlands (NRCS) and the Choptank Benchmark Watershed CEAP (ARS) have established a partnership to assess and ultimately enhance the effect of conservation practices on ecosystem services provided by wetlands in the Choptank Watershed. The provision of these wetland services (e.g., pollutant red...

  4. Identifying Riparian Buffer Effects on Stream 1 Nitrogen in Southeastern Coastal Plain Watersheds

    Science.gov (United States)

    Riparian areas have long demonstrated their ability to attenuate nutrients and sediments from agricultural runoff at the field scale; however, to inform effective nutrient management choices, the impact of riparian buffers on water quality services must be assessed at watershed s...

  5. Watershed-scale effects of urbanization on sediment export: Assessment and policy

    Science.gov (United States)

    Randhir, Timothy

    2003-06-01

    Built components of watersheds are associated with impervious surfaces that alter hydrology, disrupt ecosystems, and affect water quality. This study focuses on the impervious factor as a tool for assessment and policy design to address water quality impacts. The empirical model uses a combination of watershed simulation and statistical regression modeling to study sediment loading at various stages of urbanization. The policy design is based on private behavior in a watershed setting to develop appropriate economic approaches. The incentives through taxes, subsidies, and cost sharing are based on water quality impacts. It was observed that nonlinearity in response functions resulted in transition effects that are continuous. This is due to gradual shifts in landscape characteristics as a result of urbanization. On a regional basis, impervious factor had a varying effect on water quality and depend on the state of urbanization and spatial characteristics. Economic policies based on a metric like impervious cover can be used to mitigate the negative effects of urbanization in watersheds through use of appropriate BMPs, urban forestry methods, and spatial targeting. While linear rules in policy are easier to implement, nonlinear rules were more effective in representing the changes in marginal social cost of impervious factor, especially initial and late stages of urbanization. There exists excellent scope in using this targeted policy to address specific problems associated with complex urban systems.

  6. The Effect of Lifting Speed on Cumulative and Peak Biomechanical Loading for Symmetric Lifting Tasks

    Directory of Open Access Journals (Sweden)

    Kasey O. Greenland

    2013-06-01

    Conclusion: Based on peak values, BCF is highest for fast speeds, but the BCF cumulative loading is highest for slow speeds, with the largest difference between fast and slow lifts. This may imply that a slow lifting speed is at least as hazardous as a fast lifting speed. It is important to consider the duration of lift when determining risks for back and shoulder injuries due to lifting and that peak values alone are likely not sufficient.

  7. Developing the scientific basis for assessing cumulative effects of wetland loss and degradation on landscape functions: Status, perspectives, and prospects

    Science.gov (United States)

    Bedford, Barbara L.; Preston, Eric M.

    1988-09-01

    The incongruity between the regional and national scales at which wetland losses are occurring, and the project-specific scale at which wetlands are regulated and studied, has become obvious. This article presents a synthesis of recent efforts by the US Environmental Protection Agency and the Ecosystems Research Center at Cornell University to bring wetland science and regulation into alignment with the reality of the cumulative effects of wetland loss and degradation on entire landscapes and regions. The synthesis is drawn from the other articles in this volume, the workshop that initiated them, and the scientific literature. It summarizes the status of our present scientific understanding, discusses means by which to actualize the existing potential for matching the scales of research and regulation with the scales at which effects are observed, and provides guidelines for building a stronger scientific base for landscape-level assessments of cumulative effects. It also provides the outlines for a synoptic and qualitative approach to cumulative effects assessment based on a reexamination of the generic assessment framework we proposed elsewhere in this volume. The primary conclusion to be drawn from the articles and the workshop is that a sound scientific basis for regulation will not come merely from acquiring more information on more variables. It will come from recognizing that a perceptual shift to larger temporal, spatial, and organizational scales is overdue. The shift in scale will dictate different—not necessarily more—variables to be measured in future wetland research and considered in wetland regulation.

  8. Cumulative Small Effect Genetic Markers and the Risk of Colorectal Cancer in Poland, Estonia, Lithuania, and Latvia

    Directory of Open Access Journals (Sweden)

    Pablo Serrano-Fernandez

    2015-01-01

    Full Text Available The continued identification of new low-penetrance genetic variants for colorectal cancer (CRC raises the question of their potential cumulative effect among compound carriers. We focused on 6 SNPs (rs380284, rs4464148, rs4779584, rs4939827, rs6983267, and rs10795668, already described as risk markers, and tested their possible independent and combined contribution to CRC predisposition. Material and Methods. DNA was collected and genotyped from 2330 unselected consecutive CRC cases and controls from Estonia (166 cases and controls, Latvia (81 cases and controls, Lithuania (123 cases and controls, and Poland (795 cases and controls. Results. Beyond individual effects, the analysis revealed statistically significant linear cumulative effects for these 6 markers for all samples except of the Latvian one (corrected P value = 0.018 for the Estonian, corrected P value = 0.0034 for the Lithuanian, and corrected P value = 0.0076 for the Polish sample. Conclusions. The significant linear cumulative effects demonstrated here support the idea of using sets of low-risk markers for delimiting new groups with high-risk of CRC in clinical practice that are not carriers of the usual CRC high-risk markers.

  9. Insights into integrating cumulative effects and collaborative co-management for migratory tundra caribou herds in the Northwest Territories, Canada

    Directory of Open Access Journals (Sweden)

    Anne Gunn

    2014-12-01

    Full Text Available Globally, many migratory mammals are facing threats. In northern Canada, large annual ranges expose migratory caribou to an array of human activities, including industrial exploration and development. Recognition that responses to human activities can accumulate for caribou is long-standing, but is heightened by recent declines in caribou abundance. For example, since the mid-1990s, the Bathurst herd has declined by approximately 90%, leading to severe harvest restrictions. More mines are being proposed and developed across the herd's annual range, raising questions about cumulative effects. Despite progress on assessment techniques, aboriginal groups are expressing strong concerns and frustration about gaps in responsibilities for who should monitor, mitigate, and manage cumulative effects. The core of the concern is sustainability and the related trade-offs between industrial developments relative to continued access to healthy caribou for harvesting. We offer insights into how these concerns can be addressed by building on existing concepts (adaptive management and approaches (herd management.

  10. Cumulative risk effects for the development of behaviour difficulties in children and adolescents with special educational needs and disabilities.

    Science.gov (United States)

    Oldfield, Jeremy; Humphrey, Neil; Hebron, Judith

    2015-01-01

    Research has identified multiple risk factors for the development of behaviour difficulties. What have been less explored are the cumulative effects of exposure to multiple risks on behavioural outcomes, with no study specifically investigating these effects within a population of young people with special educational needs and disabilities (SEND). Furthermore, it is unclear whether a threshold or linear risk model better fits the data for this population. The sample included 2660 children and 1628 adolescents with SEND. Risk factors associated with increases in behaviour difficulties over an 18-month period were summed to create a cumulative risk score, with this explanatory variable being added into a multi-level model. A quadratic term was then added to test the threshold model. There was evidence of a cumulative risk effect, suggesting that exposure to higher numbers of risk factors, regardless of their exact nature, resulted in increased behaviour difficulties. The relationship between risk and behaviour difficulties was non-linear, with exposure to increasing risk having a disproportionate and detrimental impact on behaviour difficulties in child and adolescent models. Interventions aimed at reducing behaviour difficulties need to consider the impact of multiple risk variables. Tailoring interventions towards those exposed to large numbers of risks would be advantageous.

  11. Quantifying process-based mitigation strategies in historical context: separating multiple cumulative effects on river meander migration.

    Directory of Open Access Journals (Sweden)

    Alexander K Fremier

    Full Text Available Environmental legislation in the US (i.e. NEPA requires defining baseline conditions on current rather than historical ecosystem conditions. For ecosystems with long histories of multiple environmental impacts, this baseline method can subsequently lead to a significantly altered environment; this has been termed a 'sliding baseline'. In river systems, cumulative effects caused by flow regulation, channel revetment and riparian vegetation removal significantly impact floodplain ecosystems by altering channel dynamics and precluding subsequent ecosystem processes, such as primary succession. To quantify these impacts on floodplain development processes, we used a model of river channel meander migration to illustrate the degree to which flow regulation and riprap impact migration rates, independently and synergistically, on the Sacramento River in California, USA. From pre-dam conditions, the cumulative effect of flow regulation alone on channel migration is a reduction by 38%, and 42-44% with four proposed water diversion project scenarios. In terms of depositional area, the proposed water project would reduce channel migration 51-71 ha in 130 years without current riprap in place, and 17-25 ha with riprap. Our results illustrate the utility of a modeling approach for quantifying cumulative impacts. Model-based quantification of environmental impacts allow scientists to separate cumulative and synergistic effects to analytically define mitigation measures. Additionally, by selecting an ecosystem process that is affected by multiple impacts, it is possible to consider process-based mitigation scenarios, such as the removal of riprap, to allow meander migration and create new floodplains and allow for riparian vegetation recruitment.

  12. Examining water quality effects of riparian wetland loss and restoration scenarios in a southern ontario watershed.

    Science.gov (United States)

    Yang, Wanhong; Liu, Yongbo; Ou, Chunping; Gabor, Shane

    2016-06-01

    Wetland conservation has two important tasks: The first is to halt wetland loss and the second is to conduct wetland restoration. In order to facilitate these tasks, it is important to understand the environmental degradation from wetland loss and the environmental benefits from wetland restoration. The purpose of the study is to develop SWAT based wetland modelling to examine water quality effects of riparian wetland loss and restoration scenarios in the 323-km(2) Black River watershed in southern Ontario, Canada. The SWAT based wetland modelling was set up, calibrated and validated to fit into watershed conditions. The modelling was then applied to evaluate various scenarios of wetland loss from existing 7590 ha of riparian wetlands (baseline scenario) to 100% loss, and wetland restoration up to the year 1800 condition with 11,237 ha of riparian wetlands (100% restoration). The modelling was further applied to examine 100% riparian wetland loss and restoration in three subareas of the watershed to understand spatial pattern of water quality effects. Modelling results show that in comparing to baseline condition, the sediment, total nitrogen (TN), and total phosphorus (TP) loadings increase by 251.0%, 260.5%, and 890.9% respectively for 100% riparian wetland loss, and decrease by 34.5%, 28.3%, and 37.0% respectively for 100% riparian wetland restoration. Modelling results also show that as riparian wetland loss increases, the corresponding environmental degradation worsens at accelerated rates. In contrast, as riparian wetland restoration increases, the environmental benefits improve but at decelerated rates. Particularly, the water quality effects of riparian wetland loss or restoration show considerable spatial variations. The watershed wetland modelling contributes to inform decisions on riparian wetland conservation or restoration at different rates. The results further demonstrate the importance of targeting priority areas for stopping riparian wetland loss

  13. Effect of land use land cover change on soil erosion potential in an agricultural watershed.

    Science.gov (United States)

    Sharma, Arabinda; Tiwari, Kamlesh N; Bhadoria, P B S

    2011-02-01

    Universal soil loss equation (USLE) was used in conjunction with a geographic information system to determine the influence of land use and land cover change (LUCC) on soil erosion potential of a reservoir catchment during the period 1989 to 2004. Results showed that the mean soil erosion potential of the watershed was increased slightly from 12.11 t ha(-1) year(-1) in the year 1989 to 13.21 t ha(-1) year(-1) in the year 2004. Spatial analysis revealed that the disappearance of forest patches from relatively flat areas, increased in wasteland in steep slope, and intensification of cultivation practice in relatively more erosion-prone soil were the main factors contributing toward the increased soil erosion potential of the watershed during the study period. Results indicated that transition of other land use land cover (LUC) categories to cropland was the most detrimental to watershed in terms of soil loss while forest acted as the most effective barrier to soil loss. A p value of 0.5503 obtained for two-tailed paired t test between the mean erosion potential of microwatersheds in 1989 and 2004 also indicated towards a moderate change in soil erosion potential of the watershed over the studied period. This study revealed that the spatial location of LUC parcels with respect to terrain and associated soil properties should be an important consideration in soil erosion assessment process.

  14. Modeling flood reduction effects of low impact development at a watershed scale.

    Science.gov (United States)

    Ahiablame, Laurent; Shakya, Ranish

    2016-04-15

    Low impact development (LID) is a land development approach that seeks to mimic a site's pre-development hydrology. This study is a case study that assessed flood reduction capabilities of large-scale adoption of LID practices in an urban watershed in central Illinois using the Personal Computer Storm Water Management Model (PCSWMM). Two flood metrics based on runoff discharge were developed to determine action flood (43 m(3)/s) and major flood (95 m(3)/s). Four land use scenarios for urban growth were evaluated to determine the impacts of urbanization on runoff and flooding. Flood attenuation effects of porous pavement, rain barrel, and rain garden at various application levels were also evaluated as retrofitting technologies in the study watershed over a period of 30 years. Simulation results indicated that increase in urban land use from 50 to 94% between 1992 and 2030 increased average annual runoff and flood events by more than 30%, suggesting that urbanization without sound management would increase flood risks. The various implementation levels of the three LID practices resulted in 3-47% runoff reduction in the study watershed. Flood flow events that include action floods and major floods were also reduced by 0-40%, indicating that LID practices can be used to mitigate flood risk in urban watersheds. The study provides an insight into flood management with LID practices in existing urban areas.

  15. Feeding broiler breeder males. 2. Effect of cumulative rearing nutrition on body weight, shank length, comb height, and fertility.

    Science.gov (United States)

    Romero-Sanchez, H; Plumstead, P W; Leksrisompong, N; Brake, J

    2007-01-01

    Two experiments were conducted to evaluate the effects of 2 planes (low and high) of cumulative nutrient intake during the rearing period on performance of broiler breeder males. The low cumulative nutrition program supplied 29,580 kcal of ME and 1,470 g of CP, whereas the high cumulative nutrition program supplied 33,500 kcal of ME and 1,730 g of CP to photostimulation at 21 wk of age. Two diets (LoDiet and HiDiet) were used with a single feeding program in experiment 1. In experiment 2, a single diet with 2 feeding programs (LoFeed and HiFeed) was used. In experiment 1, the 2 diets were blended from 21 to 24 wk to provide a gradual transition to a single common laying breeder diet that was fed during the production period. At 21 wk of age in experiment 2, males were divided into light or heavy BW groups to complete a 2 x 2 factorial design during the production period. The high plane of nutrition increased BW, shank length, and comb height during the rearing period, but the differences disappeared after 28 wk of age. Retrospective analysis showed that the heavy males at 21 wk of age in experiment 2 were also the heaviest males at 8 wk of age. Both low plane groups (LoDiet in experiment 1 and LoFeed in experiment 2) exhibited better fertility during late production. A cumulative nutrient intake during the rearing period of 29,580 kcal of ME and 1,470 g of CP was minimally sufficient for subsequent male reproductive performance.

  16. Instrumental variables estimation of exposure effects on a time-to-event response using structural cumulative survival models

    DEFF Research Database (Denmark)

    Martinussen, T.; Vansteelandt, S.; Tchetgen, E. J. Tchetgen;

    2016-01-01

    of complications due to censoring and survivorship bias. In this paper, we make a novel proposal under a class of structural cumulative survival models which parameterize time-varying effects of a point exposure directly on the scale of the survival function; these models are essentially equivalent with a semi......-parametric variant of the instrumental variables additive hazards model. We propose a class of recursive instrumental variable estimators for these exposure effects, and derive their large sample properties along with inferential tools. We examine the performance of the proposed method in simulation studies...

  17. An Adaptive Watershed Management Assessment Based on Watershed Investigation Data

    Science.gov (United States)

    Kang, Min Goo; Park, Seung Woo

    2015-05-01

    The aim of this study was to assess the states of watersheds in South Korea and to formulate new measures to improve identified inadequacies. The study focused on the watersheds of the Han River basin and adopted an adaptive watershed management framework. Using data collected during watershed investigation projects, we analyzed the management context of the study basin and identified weaknesses in water use management, flood management, and environmental and ecosystems management in the watersheds. In addition, we conducted an interview survey to obtain experts' opinions on the possible management of watersheds in the future. The results of the assessment show that effective management of the Han River basin requires adaptive watershed management, which includes stakeholders' participation and social learning. Urbanization was the key variable in watershed management of the study basin. The results provide strong guidance for future watershed management and suggest that nonstructural measures are preferred to improve the states of the watersheds and that consistent implementation of the measures can lead to successful watershed management. The results also reveal that governance is essential for adaptive watershed management in the study basin. A special ordinance is necessary to establish governance and aid social learning. Based on the findings, a management process is proposed to support new watershed management practices. The results will be of use to policy makers and practitioners who can implement the measures recommended here in the early stages of adaptive watershed management in the Han River basin. The measures can also be applied to other river basins.

  18. Fire effects on hydrochemistry of streams draining watersheds with continuous permafrost distribution in Central Siberia

    Science.gov (United States)

    Prokushkin, Anatoly; Pokrovsky, Oleg; Kawahigashi, Masayuki; Viers, Jerome

    2010-05-01

    Wildfires, assumed to be the main disturbance factor in the boreal biome, are tended to increase in frequency and severity under "dry warming" (Conard et al. 2002). Short fire-return interval in larch dominated permafrost terrains of Siberia (Kharuk et al., 2008) exert significant control on ecosystem biogeochemical cycling throughout the complex influences of deforestation, ground vegetation and organic layer combustion as well as deepen soil active layer. Despite extensive research of fire impact on carbon exchange between soil, forest biomass and atmosphere in permafrost affected regions of Siberia, much less is known on the role of fire in control of element transport in rivers and watersheds affected by fire events. To analyze the effect of fires on chemical composition of surface fluids in permafrost zone, fourteen small forested watersheds (3-25 km2) have been selected in mid-stream of Nizhnyaya Tunguska River (Yenissey basin, Central Siberia, Russia). Analysis of larch trees in forest stands of the area demonstrated that presumably all basins were affected by wildfires in the past. Selected watersheds have been influenced by ground fires (>90% of watershed area) ca 110, 60 and 15 years ago (respectively in 1899, 1947 and 1993). Water sampling campaign has been conducted from snowmelt (mid-May) to the start of freezing (mid-October) on weekly and/or monthly interval in 2006-2009. In this study, we analyzed the dissolved loads for major and trace element concentrations. In terms of concentration changes in the course of the year, concentrations of dissolved organic carbon (DOC as well as associated elements like Fe, Al, Y and REE) and inorganic ions (e.g. DIC, Cl, Ca, Na, Mg etc.) demonstrated opposite tendencies during a frost-free season in all streams. However, basins with recent fire effect exhibited generally lower DOC concentrations in streams along with much more pronounced seasonal increase in concentrations of inorganic compounds. The increased

  19. Unknown age in health disorders: A method to account for its cumulative effect and an application to feline viruses interactions.

    Science.gov (United States)

    Hellard, Eléonore; Pontier, Dominique; Siberchicot, Aurélie; Sauvage, Frank; Fouchet, David

    2015-06-01

    Parasite interactions have been widely evidenced experimentally but field studies remain rare. Such studies are essential to detect interactions of interest and access (co)infection probabilities but face methodological obstacles. Confounding factors can create statistical associations, i.e. false parasite interactions. Among them, host age is a crucial covariate. It influences host exposition and susceptibility to many infections, and has a mechanical effect, older individuals being more at risk because of a longer exposure time. However, age is difficult to estimate in natural populations. Hence, one should be able to deal at least with its cumulative effect. Using a SI type dynamic model, we showed that the cumulative effect of age can generate false interactions theoretically (deterministic modeling) and with a real dataset of feline viruses (stochastic modeling). The risk to wrongly conclude to an association was maximal when parasites induced long-lasting antibodies and had similar forces of infection. We then proposed a method to correct for this effect (and for other potentially confounding shared risk factors) and made it available in a new R package, Interatrix. We also applied the correction to the feline viruses. It offers a way to account for an often neglected confounding factor and should help identifying parasite interactions in the field, a necessary step towards a better understanding of their mechanisms and consequences. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  20. The effect of watershed scale on HEC-HMS calibrated parameters: a case study in the Clear Creek watershed in Iowa, US

    Directory of Open Access Journals (Sweden)

    H. L. Zhang

    2013-07-01

    Full Text Available In this paper, we use the Hydrologic Modeling System (HEC-HMS to simulate two flood events to investigate the effect of watershed subdivision in terms of performance, the calibrated parameter values, the description of hydrologic processes, and the subsequent interpretation of water balance components. We use Stage IV hourly NEXRAD precipitation as the meteorological input for ten model configurations with variable sub-basin sizes. Model parameters are automatically optimized to fit the observed data. The strategy is implemented in Clear Creek Watershed (CCW, which is located in the upper Mississippi River basin. Results show that most of the calibrated parameter values are sensitive to the basin partition scheme and that the relative relevance of physical processes, described by the model, change depending on watershed subdivision. In particular, our results show that parameters derived from different model implementations attribute losses in the system to completely different physical phenomena without a notable effect on the model's performance. Our work adds to the body of evidence demonstrating that automatically calibrated parameters in hydrological models can lead to an incorrect prescription of the internal dynamics of runoff production and transport. Furthermore, it demonstrates that model implementation adds a new dimension to the problem of non-uniqueness in hydrological models.

  1. Effectiveness of alternative management scenarios on the sediment load in a Mediterranean agricultural watershed

    Directory of Open Access Journals (Sweden)

    Ossama M. M. Abdelwahab

    2014-11-01

    Full Text Available The Annualised Agricultural Non-point Source model was used to evaluate the effectiveness of different management practices to control the soil erosion and sediment load in the Carapelle watershed, a Mediterranean medium-size watershed (506 km2 located in Apulia, Southern Italy. The model was previously calibrated and validated using five years of runoff and sediment load data measured at a monitoring station located at Ordona - Ponte dei Sauri Bridge. A total of 36 events were used to estimate the performance of the model during the period 2007-2011. The model performed well in predicting runoff, as the high values of the coefficients of efficiency and determination during the validation process showed. The peak flows predictions were satisfactory especially for the high flow events; the prediction capability of sediment load was good, even if a slight over-estimation was observed. Simulations of alternative management practices show that converting the most eroding cropland cells (13.5% of the catchment area to no tillage would reduce soil erosion by 30%, while converting them to grass or forest would reduce soil erosion by 36.5% in both cases. A crop rotation of wheat and a forage crop can also provide an effective way for soil erosion control as it reduces erosion by 69%. Those results can provide a good comparative analysis for conservation planners to choose the best scenarios to be adopted in the watershed to achieve goals in terms of soil conservation and water quality.

  2. No-tillage effects on N and P exports across a rice-planted watershed.

    Science.gov (United States)

    Liang, Xinqiang; Wang, Zhibo; Zhang, Yixiang; Zhu, Chunyan; Lin, Limin; Xu, Lixian

    2016-05-01

    No tillage (NT) can be used as a management tool to alleviate the negative effects of agricultural practices on the environment by reducing the runoff volume and nutrient exports. The main objective of this research was to quantify the effect of NT on nitrogen (N) and phosphorus (P) exports across a rice-planted watershed using the soil and water assessment tool (SWAT) model. Results show that total N and P runoff exports from rice fields across the watershed ranged from 7.2 to 22.8 kg N/ha and 0.56 to 6.80 kg P/ha, respectively, over five rice-growing seasons under conventional tillage (CT) practice. The adoption of NT reduced the runoff volume, and the total N and total P exports by 25.9, 8.5, and 7.8 %, respectively, compared with the total exports under CT practice in the same study area. Rice yields were reduced by 0.7-1.9 % within the first 4 years after the adoption of NT, but began to rise in the fifth year. These results suggest that a long-term period of NT practice is necessary to reduce N and P exports without comprising the rice yield on rice-planted watersheds. In addition, the benefits of implementing NT practice alone were limited, and other practices, such as water and nutrient management, should be combined with NT practice.

  3. The Choptank Watershed Wetland Conservation Effects Assessment Project: Monitoring the Effect of Wetland Conservation Practices on Water Quality

    Science.gov (United States)

    The Choptank Watershed Wetland Conservation Effects Assessment Project (CEAP) brings together an interdisciplinary group of experts and resources from multiple federal agencies and the University of Maryland to assess the ability of native, restored, and prior-converted wetlands on cropland to impro...

  4. THE HYDROLOGICAL EFFECT UNDER HUMAN ACTIVITIES IN THE INLAND WATERSHEDS OF XINJIANG, CHINA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Natural environment, inland water distribution and water circulation has been changed greatly affected by human activities in Xinjiang, China. Human activities developed quickly in the inland watersheds in Xinjiang after 1950. More than 50% of river water is drawn into irrigation area, and all water in parts of little river is drawn to canal or reservoirs. However,there is evident hydrological effect caused by human activities. 1 ) water distribution in arid land has changed. A lot of river water is drawn into oasis and water table inside of oasis has risen but declined out of oasis. However, water table has declined in some cities because of over pumping for groundwater. 2) Stream process has changed after water drawing and drainage for irrigation. Runoff in the lower reaches of river has generally decreased, and the lower reaches of some rivers are even disappeared for stream. 3) Large watersheds have been divided into several small watersheds. In some tributaries, most of the river water has drawn to irrigation area so that stream in the lower reaches has disappeared for years. 4) Evaporation at oasis has increased from 50 - 200mm/a to 800 - 1300mm/a after reclamation. But it decreased to 50mm/a or less out of oasis. Some lakes have reduced or dried. Water system with canals and reservoirs has appeared in the oases. 5) Water quality of inland rivers and lakes has generally deteriorated because it accepts drainage water from farmland and factories. 6) Effective scale of human activities on hydrological process in arid land has expanded from separate rivers to all watersheds; from surface water to groundwater; fromdrought season to flood season; and from single year to several years. Scale of the effect of human activities to hydrological process is going larger and larger. Along with the effective usage of water resources in the inland watershed in Xinjiang, the hydrological effect of human activities will be mainly change to: 1 )river in pain area will be

  5. Effect of land tenure and stakeholders attitudes on optimization of conservation practices in agricultural watersheds

    Science.gov (United States)

    Piemonti, A. D.; Babbar-Sebens, M.; Luzar, E. J.

    2012-12-01

    Modeled watershed management plans have become valuable tools for evaluating the effectiveness and impacts of conservation practices on hydrologic processes in watersheds. In multi-objective optimization approaches, several studies have focused on maximizing physical, ecological, or economic benefits of practices in a specific location, without considering the relationship between social systems and social attitudes on the overall optimality of the practice at that location. For example, objectives that have been commonly used in spatial optimization of practices are economic costs, sediment loads, nutrient loads and pesticide loads. Though the benefits derived from these objectives are generally oriented towards community preferences, they do not represent attitudes of landowners who might operate their land differently than their neighbors (e.g. farm their own land or rent the land to someone else) and might have different social/personal drivers that motivate them to adopt the practices. In addition, a distribution of such landowners could exist in the watershed, leading to spatially varying preferences to practices. In this study we evaluated the effect of three different land tenure types on the spatial-optimization of conservation practices. To perform the optimization, we used a uniform distribution of land tenure type and a spatially varying distribution of land tenure type. Our results show that for a typical Midwestern agricultural watershed, the most optimal solutions (i.e. highest benefits for minimum economic costs) found were for a uniform distribution of landowners who operate their own land. When a different land-tenure was used for the watershed, the optimized alternatives did not change significantly for nitrates reduction benefits and sediment reduction benefits, but were attained at economic costs much higher than the costs of the landowner who farms her/his own land. For example, landowners who rent to cash-renters would have to spend ~120

  6. Effect of land use change on water discharge in Srepok watershed, Central Highland, Viet Nam

    Directory of Open Access Journals (Sweden)

    Nguyen Thi Ngoc Quyen

    2014-09-01

    Full Text Available Srepok watershed plays an important role in Central Highland in Viet Nam. It impacts to developing social-economic conditions. Therefore, it is necessary to research elements which impact to natural resources in this watershed. The Soil and Water Assessment Tool (SWAT model and Geography Information System (GIS were used to simulate water discharge in the Srepok watershed. The objectives of the research were to apply GIS and SWAT model for simulation water discharge and then, we assessed land use change which impacted on water discharge in the watershed. The observed stream flow data from Ban Don Stream gauge station was used to calibrate for the period from 1981 to 2000 and then validate for the period from 2001 to 2009. After using SWAT-CUP software to calibration, NSI reached 0.63 and R square value achieved 0.64 from 2004 to 2008 in calibration and NSI gained good level at 0.74 and R square got 0.75 from 2009 to 2012 in validation step at Ban Don Station. After that, land cover in 2010 was processed like land cover in 2000 and set up SWAT model again. The simulated water discharge in scenario 1 (land use 2000 was compared with scenario 2 (land use 2010, the simulation result was not significant difference between two scenarios because the change of area of land use was not much enough to affect the fluctuation of water discharge. However, the effect of land cover on water resource could be seen clearly via total water yield. The percentage of surface flow in 2000 was twice times more than in 2010; retard and base flow in 2000 was slightly more than in 2010. Therefore, decreased surface flow, increased infiltration capacity of water and enriched base flow resulted in the growth of land cover.

  7. Spatial resolution effect on the simulated results of watershed scale models

    Science.gov (United States)

    Epelde, Ane; Antiguedad, Iñaki; Brito, David; Jauch, Eduardo; Neves, Ramiro; Sauvage, Sabine; Sánchez-Pérez, José Miguel

    2016-04-01

    Numerical models are useful tools for water resources planning, development and management. Currently, their use is being spread and more complex modeling systems are being employed for these purposes. The adding of complexity allows the simulation of water quality related processes. Nevertheless, this implies a considerable increase on the computational requirements, which usually is compensated on the models by a decrease on their spatial resolution. The spatial resolution of the models is known to affect the simulation of hydrological processes and therefore, also the nutrient exportation and cycling processes. However, the implication of the spatial resolution on the simulated results is rarely assessed. In this study, we examine the effect of the change in the grid size on the integrated and distributed results of the Alegria River watershed model (Basque Country, Northern Spain). Variables such as discharge, water table level, relative water content of soils, nitrogen exportation and denitrification are analyzed in order to quantify the uncertainty involved in the spatial discretization of the watershed scale models. This is an aspect that needs to be carefully considered when numerical models are employed in watershed management studies or quality programs.

  8. Modeling the effects of LID practices on streams health at watershed scale

    Science.gov (United States)

    Shannak, S.; Jaber, F. H.

    2013-12-01

    Increasing impervious covers due to urbanization will lead to an increase in runoff volumes, and eventually increase flooding. Stream channels adjust by widening and eroding stream bank which would impact downstream property negatively (Chin and Gregory, 2001). Also, urban runoff drains in sediment bank areas in what's known as riparian zones and constricts stream channels (Walsh, 2009). Both physical and chemical factors associated with urbanization such as high peak flows and low water quality further stress aquatic life and contribute to overall biological condition of urban streams (Maxted et al., 1995). While LID practices have been mentioned and studied in literature for stormwater management, they have not been studied in respect to reducing potential impact on stream health. To evaluate the performance and the effectiveness of LID practices at a watershed scale, sustainable detention pond, bioretention, and permeable pavement will be modeled at watershed scale. These measures affect the storm peak flows and base flow patterns over long periods, and there is a need to characterize their effect on stream bank and bed erosion, and aquatic life. These measures will create a linkage between urban watershed development and stream conditions specifically biological health. The first phase of this study is to design and construct LID practices at the Texas A&M AgriLife Research and Extension Center-Dallas, TX to collect field data about the performance of these practices on a smaller scale. The second phase consists of simulating the performance of LID practices on a watershed scale. This simulation presents a long term model (23 years) using SWAT to evaluate the potential impacts of these practices on; potential stream bank and bed erosion, and potential impact on aquatic life in the Blunn Watershed located in Austin, TX. Sub-daily time step model simulations will be developed to simulate the effectiveness of the three LID practices with respect to reducing

  9. Modeling cumulative effects in life cycle assessment: the case of fertilizer in wheat production contributing to the global warming potential.

    Science.gov (United States)

    Laratte, Bertrand; Guillaume, Bertrand; Kim, Junbeum; Birregah, Babiga

    2014-05-15

    This paper aims at presenting a dynamic indicator for life cycle assessment (LCA) measuring cumulative impacts over time of greenhouse gas (GHG) emissions from fertilizers used for wheat cultivation and production. Our approach offers a dynamic indicator of global warming potential (GWP), one of the most used indicator of environmental impacts (e.g. in the Kyoto Protocol). For a case study, the wheat production in France was selected and considered by using data from official sources about fertilizer consumption and production of wheat. We propose to assess GWP environmental impact based on LCA method. The system boundary is limited to the fertilizer production for 1 ton of wheat produced (functional unit) from 1910 to 2010. As applied to wheat production in France, traditional LCA shows a maximum GWP impact of 500 kg CO2-eq for 1 ton of wheat production, whereas the GWP impact of wheat production over time with our approach to dynamic LCA and its cumulative effects increases to 18,000 kg CO2-eq for 1 ton of wheat production. In this paper, only one substance and one impact assessment indicator are presented. However, the methodology can be generalized and improved by using different substances and indicators.

  10. Cumulative Effects of Hypertension, Dyslipidemia, and Chronic Kidney Disease on Carotid Atherosclerosis in Chinese Patients with Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Chuang Yuan

    2014-01-01

    Full Text Available Aims. The aim of this study is to determine the extent of carotid atherosclerosis in Chinese patients with type 2 diabetes in relation to the cumulative atherosclerosis risk factors using ultrasonography. Methods. The presence of hypertension, dyslipidemia, and chronic kidney disease (CKD was documented in 106 Chinese subjects with type 2 diabetes. Subjects with 0, 1, and ≥2 additional atherosclerosis risk factors were assigned into groups 1, 2, and 3, respectively (n=17, 49, and 40, resp.. Using ultrasound, the carotid arteries were assessed for the presence of carotid plaque, plaque score, intima-media thickness (IMT, and carotid arterial stiffness. Results. With the adjustment for age and gender, the presence of plaque and plaque score were significantly higher in groups with more atherosclerosis risk factors (P 60 years old (odds ratio = 2.75; 95% CI: 1.26–6.0 and the presence of hypertension (odds ratio = 2.48; 95% CI: 1.11–5.58, dyslipidemia (odds ratio = 2.41; 95% CI: 1.05–5.51, and CKD (odds ratio = 7.80; 95% CI: 1.46–41.72 could independently predict higher plaque score (P<0.05. Conclusions. Hypertension, dyslipidemia, and CKD in Chinese patients with type 2 diabetes have cumulative effects on the burden of carotid plaque.

  11. Potential for cumulative effects of human stressors on fish, sea birds and marine mammals in Arctic waters

    Science.gov (United States)

    Andersen, Jesper H.; Berzaghi, Fabio; Christensen, Tom; Geertz-Hansen, Ole; Mosbech, Anders; Stock, Andy; Zinglersen, Karl B.; Wisz, Mary S.

    2017-01-01

    We estimate the potential for cumulative impacts from multiple anthropogenic stressors on fish, sea birds, and marine mammals in the western, southern and south-eastern parts of marine waters around Greenland. The analysis is based on a comprehensive data set representing five human activities including two proxies for climate change, as well as 25 key animal species including commercially important fish and top predators such as sea birds and marine mammals. Anthropogenic stressors are concentrated in two areas: the offshore waters south of Greenland, and especially the western coast from the Qeqertarsuaq (Disko Island) area to the southern tip of Greenland. The latter is also an area of high importance for many key species, thus the potential for cumulative impacts is high along Greenland's west coast. We conclude that this area should be under high scientific scrutiny and conservation attention. Our study is a first attempt and a stepping-stone towards more detailed and accurate estimates of the effects of multiple human stressors on Arctic marine ecosystems.

  12. Effects of site characteristics on cumulative frequency distribution of water table depth in peatlands

    Science.gov (United States)

    Bechtold, Michel; Tiemeyer, Bärbel; Frahm, Enrico; Roßkopf, Niko

    2013-04-01

    Previous studies demonstrated strong dependency of vegetation development and GHG emissions from peatlands on annual mean water table depth. It is also proposed that the duration of ponding and low water level periods are important indicators for CH4 emissions and the presence of specific plant species. Better understanding of the annual water table dynamics and the influence of site characteristics helps to explain variability of vegetation and emissions at the plot scale. It also provides essential information for a nation-wide upscaling of local gas flux measurements and for estimating the impact of regional adaption strategies. In this study, we analyze the influence of site characteristics on the cumulative frequency distribution of water table depth in a peatland. On the basis of data from about 100 sites we evaluate how distribution functions, e.g. the beta distribution function, are a tool for the systematic analysis of the site-specific frequency distribution of water table depth. Our analysis shows that it is possible to differentiate different shape types of frequency distributions, in particular left-skewed (bias towards the water table minimum), right-skewed (bias towards the water table maximum), and 'S'-shaped distributions (bias towards the mid of min and max). The shape is primarily dependent on the annual mean water table depth, but also shows dependencies on land use, peatland type, catchment size and soil properties. Forest soils are for example all characterized by a 'S'-shaped distribution. Preliminary results indicate that data sets that do not show a beta distribution are mostly from observation wells that are located close to drainage courses and/or are from sites characterized by strong water management (e.g. abruptly changing weir levels). The beta distribution might thus be a tool to identify sites with a 'non-natural' frequency distribution or erroneous data sets. Because the parameters of the beta distribution show a dependency on site

  13. Ground-Truthing Validation to Assess the Effect of Facility Locational Error on Cumulative Impacts Screening Tools

    OpenAIRE

    Sadd, J. L.; Hall, E. S.; Pastor, M.; Morello-Frosch, R. A.; D. Lowe-Liang; Hayes, J.; Swanson, C

    2015-01-01

    Researchers and government regulators have developed numerous tools to screen areas and populations for cumulative impacts and vulnerability to environmental hazards and risk. These tools all rely on secondary data maintained by government agencies as part of the regulatory and permitting process. Stakeholders interested in cumulative impacts screening results have consistently questioned the accuracy and completeness of some of these datasets. In this study, three cumulative impacts screenin...

  14. The Soft Cumulative Constraint

    CERN Document Server

    Petit, Thierry

    2009-01-01

    This research report presents an extension of Cumulative of Choco constraint solver, which is useful to encode over-constrained cumulative problems. This new global constraint uses sweep and task interval violation-based algorithms.

  15. Adaptive strategies for cumulative cultural learning.

    Science.gov (United States)

    Ehn, Micael; Laland, Kevin

    2012-05-21

    The demographic and ecological success of our species is frequently attributed to our capacity for cumulative culture. However, it is not yet known how humans combine social and asocial learning to generate effective strategies for learning in a cumulative cultural context. Here we explore how cumulative culture influences the relative merits of various pure and conditional learning strategies, including pure asocial and social learning, critical social learning, conditional social learning and individual refiner strategies. We replicate the Rogers' paradox in the cumulative setting. However, our analysis suggests that strategies that resolved Rogers' paradox in a non-cumulative setting may not necessarily evolve in a cumulative setting, thus different strategies will optimize cumulative and non-cumulative cultural learning.

  16. Watersheds in disordered media

    CERN Document Server

    Araújo, N A M; Herrmann, H J; Andrade, J S

    2014-01-01

    What is the best way to divide a rugged landscape? Since ancient times, watersheds separating adjacent water systems that flow, for example, toward different seas, have been used to delimit boundaries. Interestingly, serious and even tense border disputes between countries have relied on the subtle geometrical properties of these tortuous lines. For instance, slight and even anthropogenic modifications of landscapes can produce large changes in a watershed, and the effects can be highly nonlocal. Although the watershed concept arises naturally in geomorphology, where it plays a fundamental role in water management, landslide, and flood prevention, it also has important applications in seemingly unrelated fields such as image processing and medicine. Despite the far-reaching consequences of the scaling properties on watershed-related hydrological and political issues, it was only recently that a more profound and revealing connection has been disclosed between the concept of watershed and statistical physics o...

  17. Cumulative exposure to disadvantage and the intergenerational transmission of neighbourhood effects

    NARCIS (Netherlands)

    Hedman, L.; Manley, D.; Van Ham, M.; Östh, J.

    2012-01-01

    Studies of neighbourhood effects typically investigate the instantaneous effect of point-in-time measures of neighbourhood poverty on individual outcomes. It has been suggested that it is not solely the current neighbourhood, but also the neigh-bourhood history of an individual that is important in

  18. Paying for watershed services: an effective tool in the developing world?

    Energy Technology Data Exchange (ETDEWEB)

    Grieg-Gran, Maryanne; Porras, Ina

    2012-05-15

    Payments for watershed services (PWS) are an increasingly popular conservation and water management tool in developing countries. Some schemes are thriving, and are pro-poor. Others are stalling or have only mixed success. Most rely on public or donor finance; and other sources of funding are unlikely to play a significant role any time soon. In part, financing PWS schemes remains a challenge because the actual evidence for their effectiveness is still scanty — it is hard to prove that they actually work to benefit both livelihoods and environments. Getting more direct and concrete data on costs and benefits will be crucial to securing the long-term future of PWS schemes.

  19. Cumulative effects of white clover residues on the changes in soil ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-18

    May 18, 2009 ... percentage (17–23%) and electrical conductivity (10–20%) whereas pH ... Key words: N uptake, pasture, plant residues, residual effects, soil nutrients. ... Field experiment was conducted under rain fed conditions at the.

  20. Cumulative effects of road de-icing salt on amphibian behavior

    OpenAIRE

    Denoël, Mathieu; Bichot, Marion; Ficetola, G. Francesco; Delcourt, Johann; Ylieff, Marc; Kestemont, Patrick; Poncin, Pascal

    2010-01-01

    Despite growing evidence of the detrimental effect of chemical substances on organisms, limited research has focused on changes in behavioral patterns, in part due to the difficulties to obtain detailed quantitative data. Recent developments in efficient computer-based video analyses have allowed testing pesticide effects on model species such as the zebrafish. However, these new techniques have not yet been applied to amphibians and directly to conservation issues, i.e. to assess toxicologic...

  1. Clinical significance of cumulative biological effective dose and overall treatment time in the treatment of carcinoma cervix

    Directory of Open Access Journals (Sweden)

    Mandal Abhijit

    2007-01-01

    Full Text Available The purpose of this retrospective study is to report the radiotherapy treatment response of, and complications in, patients with cervical cancer on the basis of cumulative biologic effective dose (BED and overall treatment time (OTT. Sixty-four (stage II - 35/64; stage III - 29/64 patients of cervical cancer were treated with combination of external beam radiotherapy (EBRT and low dose rate intracavitary brachytherapy (ICBT. The cumulative BED was calculated at Point A (BED 10 ; and bladder, rectal reference points (BED 2.5 using the linear-quadratic BED equations. The local control (LC rate and 5-year disease-free survival (DFS rate in patients of stage II were comparable for BED 10 < 84.5 and BED 10 > 84.5 but were much higher for BED 10 > 84.5 than BED 10 < 84.5 ( P < 0.01 in stage III patients. In the stage II patients, The LC rate and 5-year DFS rate were comparable for OTT < 50 days and for OTT> 50 days but were much higher in stage III patients with OTT < 50 than OTT> 50 days ( P < 0.001. It was also observed that patients who received BED 2.5 < 105 had lesser rectal ( P < 0.001 and bladder complications than BED 2.5 > 105. Higher rectal complication-free survival (CFS R rate, bladder complication-free survival (CFS B rate and all-type late complication-free survival rate were observed in patients who received BED 2.5 < 105 than BED 2.5 > 105. A balanced, optimal and justified radiotherapy treatment schedule to deliver higher BED 10 (>84.5 and lower BED 2.5 (< 105 in lesser OTT (< 50 days is essential in carcinoma cervix to expect a better treatment outcome in all respects.

  2. The effects of green infrastructure on exceedance of critical shear stress in Blunn Creek watershed

    Science.gov (United States)

    Shannak, Sa'd.

    2017-09-01

    Green infrastructure (GI) has attracted city planners and watershed management professional as a new approach to control urban stormwater runoff. Several regulatory enforcements of GI implementation created an urgent need for quantitative information on GI practice effectiveness, namely for sediment and stream erosion. This study aims at investigating the capability and performance of GI in reducing stream bank erosion in the Blackland Prairie ecosystem. To achieve the goal of this study, we developed a methodology to represent two types of GI (bioretention and permeable pavement) into the Soil Water Assessment Tool, we also evaluated the shear stress and excess shear stress for stream flows in conjunction with different levels of adoption of GI, and estimated potential stream bank erosion for different median soil particle sizes using real and design storms. The results provided various configurations of GI schemes in reducing the negative impact of urban stormwater runoff on stream banks. Results showed that combining permeable pavement and bioretention resulted in the greatest reduction in runoff volumes, peak flows, and excess shear stress under both real and design storms. Bioretention as a stand-alone resulted in the second greatest reduction, while the installation of detention pond only had the least reduction percentages. Lastly, results showed that the soil particle with median diameter equals to 64 mm (small cobbles) had the least excess shear stress across all design storms, while 0.5 mm (medium sand) soil particle size had the largest magnitude of excess shear stress. The current study provides several insights into a watershed scale for GI planning and watershed management to effectively reduce the negative impact of urban stormwater runoff and control streambank erosion.

  3. Application of risk-based multiple criteria decision analysis for selection of the best agricultural scenario for effective watershed management.

    Science.gov (United States)

    Javidi Sabbaghian, Reza; Zarghami, Mahdi; Nejadhashemi, A Pouyan; Sharifi, Mohammad Bagher; Herman, Matthew R; Daneshvar, Fariborz

    2016-03-01

    Effective watershed management requires the evaluation of agricultural best management practice (BMP) scenarios which carefully consider the relevant environmental, economic, and social criteria involved. In the Multiple Criteria Decision-Making (MCDM) process, scenarios are first evaluated and then ranked to determine the most desirable outcome for the particular watershed. The main challenge of this process is the accurate identification of the best solution for the watershed in question, despite the various risk attitudes presented by the associated decision-makers (DMs). This paper introduces a novel approach for implementation of the MCDM process based on a comparative neutral risk/risk-based decision analysis, which results in the selection of the most desirable scenario for use in the entire watershed. At the sub-basin level, each scenario includes multiple BMPs with scores that have been calculated using the criteria derived from two cases of neutral risk and risk-based decision-making. The simple additive weighting (SAW) operator is applied for use in neutral risk decision-making, while the ordered weighted averaging (OWA) and induced OWA (IOWA) operators are effective for risk-based decision-making. At the watershed level, the BMP scores of the sub-basins are aggregated to calculate each scenarios' combined goodness measurements; the most desirable scenario for the entire watershed is then selected based on the combined goodness measurements. Our final results illustrate the type of operator and risk attitudes needed to satisfy the relevant criteria within the number of sub-basins, and how they ultimately affect the final ranking of the given scenarios. The methodology proposed here has been successfully applied to the Honeyoey Creek-Pine Creek watershed in Michigan, USA to evaluate various BMP scenarios and determine the best solution for both the stakeholders and the overall stream health.

  4. Coupled effects of natural and anthropogenic controls on seasonal and spatial variations of river water quality during baseflow in a coastal watershed of Southeast China.

    Directory of Open Access Journals (Sweden)

    Jinliang Huang

    demonstrates that the coupled effects of natural and anthropogenic controls involved in watershed processes, contribute to the seasonal and spatial variation of headwater stream water quality in a coastal watershed with high spatial variability and intensive anthropogenic activities.

  5. Relationships between fathers and adult children: the cumulative effects of divorce and repartnering

    NARCIS (Netherlands)

    Kalmijn, M.

    2015-01-01

    New data from a national Dutch survey are used to examine the effects of divorce and repartnering on the relationships that fathers have with their adult children. Compared with divorced fathers who live alone, repartnered fathers have less frequent contact with their children, they exchange less

  6. Relationships between fathers and adult children: The cumulative effects of divorce and repartnering

    NARCIS (Netherlands)

    Kalmijn, M.

    2015-01-01

    New data from a national Dutch survey are used to examine the effects of divorce and repartnering on the relationships that fathers have with their adult children. Compared with divorced fathers who live alone, repartnered fathers have less frequent contact with their children, they exchange less

  7. Cumulative effects of consecutive running sessions on hemolysis, inflammation and hepcidin activity.

    NARCIS (Netherlands)

    Peeling, P.; Dawson, B.; Goodman, C.; Landers, G.; Wiegerinck, E.T.G.; Swinkels, D.W.; Trinder, D.

    2009-01-01

    The effect of two running sessions completed within a 12-h period on hemolysis, inflammation, and hepcidin activity in endurance athletes was investigated. Ten males completed two experimental trials in a randomized, counterbalanced order. The two trials included (a) a one-running-session trial (T1)

  8. Relationships between fathers and adult children: The cumulative effects of divorce and repartnering

    NARCIS (Netherlands)

    Kalmijn, M.

    2015-01-01

    New data from a national Dutch survey are used to examine the effects of divorce and repartnering on the relationships that fathers have with their adult children. Compared with divorced fathers who live alone, repartnered fathers have less frequent contact with their children, they exchange less su

  9. Relationships between fathers and adult children: the cumulative effects of divorce and repartnering

    NARCIS (Netherlands)

    Kalmijn, M.

    2015-01-01

    New data from a national Dutch survey are used to examine the effects of divorce and repartnering on the relationships that fathers have with their adult children. Compared with divorced fathers who live alone, repartnered fathers have less frequent contact with their children, they exchange less su

  10. Forecasting the Relative and Cumulative Effects of Multiple Stressors on At-risk Populations

    Science.gov (United States)

    2011-08-01

    and Lennon 1999) and changes in phenology (Beebee 1995, Crick and Sparks 1999). Furthermore, climate change has been clearly implicated in species...addressing the issue of spatial scale and variation in modeling approaches is to create ensembles of models or model predictions. Predictions resulting...the understanding of URTD population-level effects and has led to speculation that environmental factors may be partly responsible for the variation

  11. Cumulative effect of Forbush decreases in the heliospheric modulation during the present solar cycle

    Science.gov (United States)

    Agrawal, S. P.; Mishra, B. L.; Jain, A. K.

    1985-01-01

    A monthly Forbush decrease index (Fd-I) is generated and it is compared with the observed long term chnges in the cosmic ray intensity near earth at energies greater than or equal to 1 Gev over 1976-83. Significant correlation is observed between the two except for 1978. Such an effect is also seen in the correlation plot between the solar flare index (SFI) and Fd-I.

  12. Analysis of the cumulative effect of schizophrenia-related single nucleotide polymorphisms

    OpenAIRE

    Lozano R; Marín R; Freire I; Santacruz MJ; Pascual-García A

    2014-01-01

    Roberto Lozano,1 Reyes Marín,2 Isabel Freire,2 María-Jesús Santacruz,2 Asunción Pascual-García21Pharmacy Department, 2Psychiatry Department, Hospital Real de Nuestra Señora de Gracia, Zaragoza, SpainIt is currently believed that predisposition for schizophrenia stems from the combined effect of multiple common polymorphisms. Thus, no genetic variant is considered to be fully responsible for the disease. For this reason, analysi...

  13. Restoring fish ecological quality in estuaries: Implication of interactive and cumulative effects among anthropogenic stressors.

    Science.gov (United States)

    Teichert, Nils; Borja, Angel; Chust, Guillem; Uriarte, Ainhize; Lepage, Mario

    2016-01-15

    Estuaries are subjected to multiple anthropogenic stressors, which have additive, antagonistic or synergistic effects. Current challenges include the use of large databases of biological monitoring surveys (e.g. the European Water Framework Directive) to help environmental managers prioritizing restoration measures. This study investigated the impact of nine stressor categories on the fish ecological status derived from 90 estuaries of the North East Atlantic countries. We used a random forest model to: 1) detect the dominant stressors and their non-linear effects; 2) evaluate the ecological benefits expected from reducing pressure from stressors; and 3) investigate the interactions among stressors. Results showed that largest restoration benefits were expected when mitigating water pollution and oxygen depletion. Non-additive effects represented half of pairwise interactions among stressors, and antagonisms were the most common. Dredged sediments, flow changes and oxygen depletion were predominantly implicated in non-additive interactions, whereas the remainder stressors often showed additive impacts. The prevalence of interactive impacts reflects a complex scenario for estuaries management; hence, we proposed a step-by-step restoration scheme focusing on the mitigation of stressors providing the maximum of restoration benefits under a multi-stress context.

  14. The effects of spatial scale on breakdown of leaves in a tropical watershed.

    Science.gov (United States)

    Rezende, Renan S; Petrucio, Mauricio M; Gonçalves, José F

    2014-01-01

    The objective was to assess the effects of natural variation in the physical structure of the environment on biological communities and on the processing of Eucalyptus cloeziana and Inga laurina and to identify the controlling factors at different scales along stream order gradients. The study area consisted of 14 sampling sites distributed within a tropical watershed (1st, 2nd, 3rd and 4th order streams replicated in 4 sub-basins). Our samples consisted of 3 g of leaves of E. cloeziana (high-quality) and I. laurina (low-quality) placed in 252 bags with 10mm mesh (measured by the chemical composition of the detritus). Four samples of each leaf type were collected periodically (three times) over a period of 75-125 days and washed on a sieve to separate the invertebrates. A series of leaf disks were cut to determine ash-free dry mass, polyphenol, lignin, cellulose, total microbial biomass and fungal biomass, and the remaining material was oven-dried to determine the dry weight. We performed analyses within and between spatial scales (regional and local) to assess which watershed scale was the more import determinant of the leaf breakdown rate (k). The microbial and shredder were most influenced at the local scale (stream order). Shredders were influenced by microorganisms, with stronger interactions between them than were found to drive the k at the local scale. Moreover, differences in the overall k and abiotic variables were more strongly influenced at the regional scale (sub-basin), showing that the study scale alters the response of the studied variables. We found higher k values at higher values of water velocity, dissolved oxygen and temperature, all of which accelerate biological metabolism in response to variations on the regional scale. Watersheds with warmer microclimates and streams with higher nutrient levels and oxygen could be accelerating the ecosystem metabolism, independent of the detritus quality.

  15. The effects of spatial scale on breakdown of leaves in a tropical watershed.

    Directory of Open Access Journals (Sweden)

    Renan S Rezende

    Full Text Available The objective was to assess the effects of natural variation in the physical structure of the environment on biological communities and on the processing of Eucalyptus cloeziana and Inga laurina and to identify the controlling factors at different scales along stream order gradients. The study area consisted of 14 sampling sites distributed within a tropical watershed (1st, 2nd, 3rd and 4th order streams replicated in 4 sub-basins. Our samples consisted of 3 g of leaves of E. cloeziana (high-quality and I. laurina (low-quality placed in 252 bags with 10mm mesh (measured by the chemical composition of the detritus. Four samples of each leaf type were collected periodically (three times over a period of 75-125 days and washed on a sieve to separate the invertebrates. A series of leaf disks were cut to determine ash-free dry mass, polyphenol, lignin, cellulose, total microbial biomass and fungal biomass, and the remaining material was oven-dried to determine the dry weight. We performed analyses within and between spatial scales (regional and local to assess which watershed scale was the more import determinant of the leaf breakdown rate (k. The microbial and shredder were most influenced at the local scale (stream order. Shredders were influenced by microorganisms, with stronger interactions between them than were found to drive the k at the local scale. Moreover, differences in the overall k and abiotic variables were more strongly influenced at the regional scale (sub-basin, showing that the study scale alters the response of the studied variables. We found higher k values at higher values of water velocity, dissolved oxygen and temperature, all of which accelerate biological metabolism in response to variations on the regional scale. Watersheds with warmer microclimates and streams with higher nutrient levels and oxygen could be accelerating the ecosystem metabolism, independent of the detritus quality.

  16. The Effects of Spatial Scale on Breakdown of Leaves in a Tropical Watershed

    Science.gov (United States)

    Rezende, Renan S.; Petrucio, Mauricio M.; Gonçalves, José F.

    2014-01-01

    The objective was to assess the effects of natural variation in the physical structure of the environment on biological communities and on the processing of Eucalyptus cloeziana and Inga laurina and to identify the controlling factors at different scales along stream order gradients. The study area consisted of 14 sampling sites distributed within a tropical watershed (1st, 2nd, 3rd and 4th order streams replicated in 4 sub-basins). Our samples consisted of 3 g of leaves of E. cloeziana (high-quality) and I. laurina (low-quality) placed in 252 bags with 10mm mesh (measured by the chemical composition of the detritus). Four samples of each leaf type were collected periodically (three times) over a period of 75–125 days and washed on a sieve to separate the invertebrates. A series of leaf disks were cut to determine ash-free dry mass, polyphenol, lignin, cellulose, total microbial biomass and fungal biomass, and the remaining material was oven-dried to determine the dry weight. We performed analyses within and between spatial scales (regional and local) to assess which watershed scale was the more import determinant of the leaf breakdown rate (k). The microbial and shredder were most influenced at the local scale (stream order). Shredders were influenced by microorganisms, with stronger interactions between them than were found to drive the k at the local scale. Moreover, differences in the overall k and abiotic variables were more strongly influenced at the regional scale (sub-basin), showing that the study scale alters the response of the studied variables. We found higher k values at higher values of water velocity, dissolved oxygen and temperature, all of which accelerate biological metabolism in response to variations on the regional scale. Watersheds with warmer microclimates and streams with higher nutrient levels and oxygen could be accelerating the ecosystem metabolism, independent of the detritus quality. PMID:24810918

  17. Early life adversity potentiates the effects of later life stress on cumulative physiological dysregulation

    DEFF Research Database (Denmark)

    Dich, Nadya; Hansen, Åse Marie; Avlund, Kirsten

    2015-01-01

    Background and Objectives: Previous research indicates that early life adversity may heighten stress reactivity and impair mechanisms for adaptive coping, suggesting that experience of stress in early life may also potentiate adults' physiological vulnerability to stress in later life. The study...... tested this hypothesis by investigating whether experience of stressful events and circumstances (SEC) in childhood or adolescence amplified the effect of adulthood SEC on physiological dysregulation (allostatic load, AL) in later midlife. Design: Observational data were used in the present study......: The results provide further insight into the mechanisms behind the "biological embedding" of childhood stress....

  18. Effect of Wildfire on Hydrological Processes in a Monoculture Invasive Grass Catchment within the Panama Canal Watershed

    Science.gov (United States)

    Regina, J. A.; Ogden, F. L.

    2014-12-01

    Hydrological processes in the humid tropics are poorly understood and an important topic when it comes to watershed management in the seasonal tropics. The Smithsonian Tropical Research Institute, Panama Canal Watershed Experiment, Agua Salud Project, seeks to understand these processes and quantify the long-term effects of different land cover and uses across the Panama Canal Watershed. One question posed by this project concerns the hydrologic role of fire in tropical environments. Within the Panama Canal Watershed, fire has seen widespread use among agriculturalists. This study focused on a monoculture invasive grass (Saccharum spontaneum) catchment. Specifically, the effects of significant wildfire events on hydrological processes in the catchment were analyzed. The catchment is within Panama's protected Soberania National Park, which is part of the greater Panama Canal Watershed. Installed instrumentation includes a rain gauge cluster, a two-stage v-notch weir, atmometer and an assortment of meteorological and automated geochemical sampling systems. Spatial, rainfall, runoff and ET data across the catchment is available from 2009-2013. Various hydrologic characteristics, such as runoff ratio, peak flow per unit area, time to peak, runoff duration, and leaf area index, from before and after the events were compared. These characteristics are related to rates of ground water recharge and the occurrence of flash floods. This study provides a baseline from which the potential impacts of fire on hydrological processes in tropical environments can be analyzed.

  19. Cumulative effects of biochar, mineral and organic fertilizers on soil organic matter

    Science.gov (United States)

    Plaza, César; López-de-Sá, Esther G.; Gascó, Gabriel; Méndez, Ana; Zaccone, Claudio

    2016-04-01

    We investigated the effect of three consecutive annual applications of biochar at rates of 0 and 20 t ha-1, in a factorial combination with a mineral fertilizer (NPK and nitrosulfate) and two types of organic amendment (municipal solid waste compost and sewage sludge), on soil organic matter in a field experiment under Mediterranean conditions. Biochar increased significantly soil organic C content and C/N ratio. In biochar-amended soils, soil organic C increased significantly with the addition of municipal solid waste compost and sewage sludge. To capture organic matter protection mechanisms related to aggregation and mineral interaction, the soil samples will be fractionated into free (unprotected), intra-macroaggregate, intra-microaggregate, and mineral-associated organic matter pools, and the isolated fractions will be subjected to further chemical and spectroscopic analysis.

  20. An approach to managing cumulative effects to groundwater resources in the Alberta oil sands

    Energy Technology Data Exchange (ETDEWEB)

    Fennell, J.; Forrest, Francine [WorleyParsons Canada, Infrastructure and Environment (Canada); Klebek, Margaret [Alberta Environment, Clean Energy Policy Branch (Canada)

    2011-07-01

    In the Athabasca region of Northern Alberta, oil sands activity has raised many concerns over how mining and extracting processes might affect groundwater quality and quantity. The groundwater management framework was developed by Alberta Environment to address these concerns by identifying and managing the potential environmental effects of oil sands activity on groundwater in a science-based manner. This paper develops the framework using risk identification and performance monitoring. The decision-making approach was conducted using decision support tools such as modeling, monitoring and management. Results showed the complexity and variability of groundwater conditions in the Athabasca region and pointed out that knowledge in this area is still developing. This paper presented how the groundwater management framework was developed and pointed out that it will have to be updated as new information arrives.

  1. Recurrence and frequency of disturbance have cumulative effect on methanotrophic activity, abundance, and community structure.

    Directory of Open Access Journals (Sweden)

    Adrian eHo

    2016-01-01

    Full Text Available Alternate prolonged drought and heavy rainfall is predicted to intensify with global warming. Desiccation-rewetting events alter the soil quality and nutrient concentrations which drive microbial-mediated processes, including methane oxidation, a key biogeochemical process catalyzed by methanotrophic bacteria. Although aerobic methanotrophs showed remarkable resilience to a suite of physical disturbances induced as a single event, their resilience to recurring disturbances is less known. Here, using a rice field soil in a microcosm study, we determined whether recurrence and frequency of desiccation-rewetting impose an accumulating effect on the methanotrophic activity. The response of key aerobic methanotroph subgroups (type Ia, Ib, and II were monitored using qPCR assays, and was supported by a t-RFLP analysis. The methanotrophic activity was resilient to recurring desiccation-rewetting, but increasing the frequency of the disturbance by two-fold significantly decreased methane uptake rate. Both the qPCR and t-RFLP analyses were congruent, showing the dominance of type Ia/Ib methanotrophs prior to disturbance, and after disturbance, the recovering community was predominantly comprised of type Ia (Methylobacter methanotrophs. Both type Ib and type II (Methylosinus/Methylocystis methanotrophs were adversely affected by the disturbance, but type II methanotrophs showed recovery over time, indicating relatively higher resilience to the disturbance. This revealed distinct, yet unrecognized traits among the methanotroph community members. Our results show that recurring desiccation-rewetting before a recovery in community abundance had an accumulated effect, compromising methanotrophic activity. While methanotrophs may recover well following sporadic disturbances, their resilience may reach a ‘tipping point’ where activity no longer recovered if disturbance persists and increase in frequency.

  2. Recurrence and Frequency of Disturbance have Cumulative Effect on Methanotrophic Activity, Abundance, and Community Structure.

    Science.gov (United States)

    Ho, Adrian; van den Brink, Erik; Reim, Andreas; Krause, Sascha M B; Bodelier, Paul L E

    2015-01-01

    Alternate prolonged drought and heavy rainfall is predicted to intensify with global warming. Desiccation-rewetting events alter the soil quality and nutrient concentrations which drive microbial-mediated processes, including methane oxidation, a key biogeochemical process catalyzed by methanotrophic bacteria. Although aerobic methanotrophs showed remarkable resilience to a suite of physical disturbances induced as a single event, their resilience to recurring disturbances is less known. Here, using a rice field soil in a microcosm study, we determined whether recurrence and frequency of desiccation-rewetting impose an accumulating effect on the methanotrophic activity. The response of key aerobic methanotroph subgroups (type Ia, Ib, and II) were monitored using qPCR assays, and was supported by a t-RFLP analysis. The methanotrophic activity was resilient to recurring desiccation-rewetting, but increasing the frequency of the disturbance by twofold significantly decreased methane uptake rate. Both the qPCR and t-RFLP analyses were congruent, showing the dominance of type Ia/Ib methanotrophs prior to disturbance, and after disturbance, the recovering community was predominantly comprised of type Ia (Methylobacter) methanotrophs. Both type Ib and type II (Methylosinus/Methylocystis) methanotrophs were adversely affected by the disturbance, but type II methanotrophs showed recovery over time, indicating relatively higher resilience to the disturbance. This revealed distinct, yet unrecognized traits among the methanotroph community members. Our results show that recurring desiccation-rewetting before a recovery in community abundance had an accumulated effect, compromising methanotrophic activity. While methanotrophs may recover well following sporadic disturbances, their resilience may reach a 'tipping point' where activity no longer recovered if disturbance persists and increase in frequency.

  3. Surface Mining and Reclamation Effects on Flood Response of Watersheds in the Central Appalachian Plateau Region

    Science.gov (United States)

    Ferrari, J. R.; Lookingbill, T. R.; McCormick, B.; Townsend, P. A.; Eshleman, K. N.

    2009-01-01

    Surface mining of coal and subsequent reclamation represent the dominant land use change in the central Appalachian Plateau (CAP) region of the United States. Hydrologic impacts of surface mining have been studied at the plot scale, but effects at broader scales have not been explored adequately. Broad-scale classification of reclaimed sites is difficult because standing vegetation makes them nearly indistinguishable from alternate land uses. We used a land cover data set that accurately maps surface mines for a 187-km2 watershed within the CAP. These land cover data, as well as plot-level data from within the watershed, are used with HSPF (Hydrologic Simulation Program-Fortran) to estimate changes in flood response as a function of increased mining. Results show that the rate at which flood magnitude increases due to increased mining is linear, with greater rates observed for less frequent return intervals. These findings indicate that mine reclamation leaves the landscape in a condition more similar to urban areas rather than does simple deforestation, and call into question the effectiveness of reclamation in terms of returning mined areas to the hydrological state that existed before mining.

  4. [Differences in urbanization process of catchments in dongjiang watershed and their effects on landscape pattern].

    Science.gov (United States)

    Ren, Wen-tao; Peng, Shao-lin; Zhou, Ting; Li, Yan

    2008-12-01

    Based on 1991, 1998, and 2006 TM images, the areas of different land use types and the landscape indices of three catchments (catchment a, b, and c, which represented upper, middle, and lower reaches, respectively) in Dongjiang watershed were analyzed, aimed to study the differences in urbanization process along Dongjiang River, and their effects on landscape pattern. The results showed that the degree and speed of urbanization increased from the upper to the lower reach of Dongjiang River. Urbanization had significantly effects on water and vegetation. Urban land area was positively correlated with water body area, and negatively correlated with forest land area. However, to some extent, urbanization stepped into a relatively high degree might benefit forest recovery. The landscape pattern of catchments a and b kept complicating from 1991 to 2006, while that of catchment c was getting complex from 1991 to 1998 and then becoming simple from 1998 to 2006, indicating that with the development of urbanization, landscape pattern presented a "simple-complex-simple" tendency. Understanding the change patterns of the landscape pattern along Dongjiang River would benefit the management and sustainable development of the watershed as a whole.

  5. Deforestation effects on biological and other important soil properties in an upland watershed of Bangladesh

    Institute of Scientific and Technical Information of China (English)

    S.M. Sirajul Haque; Sanatan Das Gupta; Sohag Miah

    2014-01-01

    Deforestation occurs at an alarming rate in upland watersheds of Bangladesh and has many detrimental effects on the environment. This study reports the effects of deforestation on soil biological proper-ties along with some important physicochemical parameters of a southern upland watershed in Bangladesh. Soils were sampled at 4 paired sites, each pair representing a deforested site and a forested site, and having similar topographical characteristics. Significantly fewer (p≤0.001) fungi and bacteria, and lower microbial respiration, active microbial biomass, metabolic and microbial quotients were found in soils of the deforested sites. Soil physical properties such as moisture content, water holding capacity, and chemical properties such as organic matter, total N, avail-able P and EC were also lower in deforested soils. Bulk density and pH were significantly higher in deforested soils. Available Ca and Mg were inconsistent between the two land uses at all the paired sites. Re-duced abundance and biomass of soil mesofauna were recorded in defor-ested soils. However, soil anecic species were more abundant in defor-ested soils than epigeic and endogeic species, which were more abundant in forested soils than on deforested sites.

  6. Effects of Forest Cover Change on Flood Characteristics in the Upper Citarum Watershed

    Directory of Open Access Journals (Sweden)

    Bambang Dwi Dasanto

    2015-02-01

    Full Text Available Information on the effect of forest cover changes on streamflow (river discharge in large-scale catchment is important to be studied. The rate of forest cover change in the Upper Citarum Watershed as a large-scale catchment is high enough to drive streamflow change, such as increase of discharge level, or flood volume. Within the research area, flood would occur when the volume of streamflow exceeded the canal capacity and inundated areas that were normally dry. Therefore, this research focused on identifying the effects of forest cover change on flood events and its distribution. The research consisted of 2 main stages; firstly, building geometric data of river and performing frequency analysis of historical and scenario discharges using an approach of probability distribution; and, secondly, flood inundation mapping using HEC-RAS model. The results showed that forest reduction have affected water yield in the downstream of Upper Citarum Watershed. In each return period, this reduction have increased river discharge level and affected the spread of flooded areas. In 2-year return period, the extent of flood as an impact of forest reduction was estimated to decrease slowly. However, in the return period of more than 2 years, the spread of flooded areas increased sharply. These proved that forest cover reduction would always increase the discharge value, but it did not always expand the inundated area.Keywords: geometric data, forest cover, water yield, return period

  7. Effects of Forest Cover Change on Flood Characteristics in the Upper Citarum Watershed

    Directory of Open Access Journals (Sweden)

    Bambang Dwi Dasanto

    2014-12-01

    Full Text Available Information on the effect of forest cover changes on streamflow (river discharge in large-scale catchment is important to be studied. The rate of forest cover change in the Upper Citarum Watershed as a large-scale catchment is high enough to drive streamflow change, such as increase of discharge level, or flood volume. Within the research area, flood would occur when the volume of streamflow exceeded the canal capacity and inundated areas that were normally dry. Therefore, this research focused on identifying the effects of forest cover change on flood events and its distribution. The research consisted of 2 main stages; firstly, building geometric data of river and performing frequency analysis of historical and scenario discharges using an approach of probability distribution; and, secondly, flood inundation mapping using HEC-RAS model. The results showed that forest reduction have affected water yield in the downstream of Upper Citarum Watershed. In each return period, this reduction have increased river discharge level and affected the spread of flooded areas. In 2-year return period, the extent of flood as an impact of forest reduction was estimated to decrease slowly. However, in the return period of more than 2 years, the spread of flooded areas increased sharply. These proved that forest cover reduction would always increase the discharge value, but it did not always expand the inundated area.

  8. The effect of recovery strategies on physical performance and cumulative fatigue in competitive basketball.

    Science.gov (United States)

    Montgomery, Paul G; Pyne, David B; Hopkins, Will G; Dorman, Jason C; Cook, Katherine; Minahan, Clare L

    2008-09-01

    To evaluate the effectiveness of recovery strategies on physical performance during a 3-day tournament style basketball competition, 29 male players (mean age 19.1 years, s= 2.1; height 1.84 m, s= 0.34; body mass 88.5 kg, s= 14.7) were assigned to one of three treatment groups: carbohydrate+stretching (7.7 g kg(-1) day(-1), s= 1.7; 'n = 9), cold water immersion (11 degrees C, 5 x 1; n = 10) or full leg compression garments (18 mmHg, approximately 18 h; n = 10). Effects of the recovery strategies on pre-post tournament performance tests were expressed as the mean change (% +/- standard deviation of the change score). Changes and differences were standardized for accumulated game time, assessed against the smallest worthwhile change for each test, and reported qualitatively. Accumulated fatigue was evident over the tournament with small to moderate impairments in performance tests. Sprint and agility performance decreased by 0.7% (s = 1.3) and 2.0% (s = 1.9) respectively. Vertical jump decreased substantially after the first day for all treatments, and remained suppressed post-tournament. Cold water immersion was substantially better in maintaining 20-m acceleration with only a 0.5% (s = 1.4) reduction in 20-m time after 3 days compared with a 3.2% (s = 1.6) reduction for compression. Cold water immersion (-1.4%, s = 1.7) and compression (-1.5%, s = 1.7) showed similar substantial benefits in maintaining line-drill performance over the tournament, whereas carbohydrate+stretching elicited a 0.4% (s =1.8) reduction. Sit-and-reach flexibility decreased for all groups, although cold water immersion resulted in the smallest reduction in flexibility. Basketball tournament play elicited small to moderate impairments in physical test performance. In conclusion, cold water immersion appears to promote better restoration of physical performance measures than carbohydrate + stretching routines and compression garments.

  9. Effect of Suburban Development and Landscape Position on Water Quality in Three Small Watersheds Within the Croton System, New York.

    Science.gov (United States)

    Hassett, J. M.; Endreny, T. A.; Wolosoff, S.; Adam, M.; Mitchell, M. J.

    2003-12-01

    Internal hydrological processes in suburban watersheds and their effects on water quality warrant investigation. Instrument clusters (throughfall collectors, suction lysimeters, monitoring wells, and shallow and deep piezometers) were installed at several locations within three small (50 - 70 ha) watersheds (one forested, two with different degrees of suburban development) in the Croton Watershed, southeastern New York. Biweekly and storm samples were analyzed for base cations, selected anions, and DOC over a one-year period. The topographic index (TI) quantified landscape position; flowpath analyses determined degree of development at each cluster, using % impervious cover as the metric. Water quality degradation was observed in sites with medium and high TI values; no such effect was observed along the ridges, i.e., low TI values. At medium TI values, areas with more than 5% impervious had degraded water quality. At high TI values, the water chemistry degradation appeared at 10% or greater impervious surface

  10. Physical activity overcomes the effects of cumulative work time on hypertension prevalence among Brazilian taxi drivers.

    Science.gov (United States)

    Vieira, Marcelo C; Sperandei, Sandro; Reis, Arianne C

    2016-05-01

    The aim of this study was to assess the physical activity profile of taxi drivers and its relationship with hypertension prevalence in this group of workers. Cross sectional exploratory study. Between November 2008 and April 2009, 491 taxi drivers from Rio de Janeiro, Brazil, answered a questionnaire focusing on previous hypertension diagnosis, occupational characteristics and physical activity habits. Two logistic models were developed to determine risk factors related to hypertension and to find variables associated with a higher probability of sedentarism. Hypertension prevalence was 22.6%. The workload of the group investigated was high. Results indicate that 'age', 'Body Mass Index', 'physical activity', and 'years as a taxi driver' are related to the probability of hypertension. Physical activity was shown to be a protection factor for hypertension, even considering the deleterious effect of time as a taxi driver. Our results also determined that the practice of physical activity is influenced by age, level of education and workload. It is recommended that programs to combat sedentary lifestyles as well as measures to reduce workloads be developed as strategies to prevent hypertension.

  11. An evaluation of the cumulative concussive effect of soccer heading in the youth population.

    Science.gov (United States)

    Janda, David H; Bir, Cynthia A; Cheney, Angela L

    2002-03-01

    Soccer is the most popular team sport in the world, with 120 million individuals participating and 16 million of these individuals being based in the United States. In addition, soccer has become the fastest growing team sport in the United States over the past 10 years. Head impact injuries have been cited as comprising 15% of all injuries related to soccer. Previous studies have identified the technique of heading as being a significant factor in head impact injuries. In fact, 85% of various subgroups of participants, 19 years of age and older, have had a diminution in cognitive function abilities on a permanent basis. It was the purpose of this study to evaluate the effect of repetitive head impacts due to heading in 57 youth soccer players with a mean age of 11.5 years. The data were collected over three seasons during the first year, which correlated to approximately 60 games and/or practices. One team of 18 boys was followed for an additional year. The data collected included a cognitive function test, as well as documentation of concussive symptoms. These cognitive evaluations, conducted at both periods of time, revealed that statistically significant differences were not evident when compared to standardized norms with the exception of verbal learning. There was an inverse relationship between the number of ball impacts and verbal learning. Of note, however, is that 49% of the year-one study group did complain of headaches after heading the ball.

  12. Effects of volume corrections and resonance decays on cumulants of net-charge distributions in a Monte Carlo hadron resonance gas model

    Science.gov (United States)

    Xu, Hao-jie

    2017-02-01

    The effects of volume corrections and resonance decays (the resulting correlations between positive charges and negative charges) on cumulants of net-proton distributions and net-charge distributions are investigated by using a Monte Carlo hadron resonance gas (MCHRG) model. The required volume distributions are generated by a Monte Carlo Glauber (MC-Glb) model. Except the variances of net-charge distributions, the MCHRG model with more realistic simulations of volume corrections, resonance decays and acceptance cuts can reasonably explain the data of cumulants of net-proton distributions and net-charge distributions reported by the STAR collaboration. The MCHRG calculations indicate that both the volume corrections and resonance decays make the cumulant products of net-charge distributions deviate from the Skellam expectations: the deviations of Sσ and κσ2 are dominated by the former effect while the deviations of ω are dominated by the latter one.

  13. The magnitude of lost ecosystem structure and function in urban streams and the effectiveness of watershed-based management (Invited)

    Science.gov (United States)

    Smucker, N. J.; Detenbeck, N. E.; Kuhn, A.

    2013-12-01

    Watershed development is a leading cause of stream impairment and increasingly threatens the availability, quality, and sustainability of freshwater resources. In a recent global meta-analysis, we found that measures of desirable ecological structure (e.g., algal, macroinvertebrate, and fish communities) and functions (e.g., metabolism, nutrient uptake, and denitrification) in streams with developed watersheds were only 23% and 34%, respectively, of those in minimally disturbed reference streams. As humans continue to alter watersheds in response to growing and migrating populations, characterizing ecological responses to watershed development and management practices is urgently needed to inform future development practices, decisions, and policy. In a study of streams in New England, we found that measures of macroinvertebrate and algal communities had threshold responses between 1-10% and 1-5% impervious cover, respectively. Macroinvertebrate communities had decreases in sensitive taxa and predators occurring from 1-3.5% and transitions in trophic and habitat guilds from 4-9% impervious cover. Sensitive algal taxa declined at 1%, followed by increases in tolerant taxa at 3%. Substantially altered algal communities persisted above 5% impervious cover and were dominated by motile taxa (sediment resistant) and those with high nutrient demands. Boosted regression tree analysis showed that sites with >65% and ideally >80% forest and wetland cover in near-stream buffers were associated with a 13-34% decrease in the effects of watershed impervious cover on algal communities. While this reduction is substantial, additional out-of-stream management efforts are needed to protect and restore stream ecosystems (e.g., created wetlands and stormwater ponds), but understanding their effectiveness is greatly limited by sparse ecological monitoring. Our meta-analysis found that restoration improved ecological structure and functions in streams by 48% and 14%, respectively, when

  14. Watershed Scale Impacts of Stormwater Green Infrastructure on Hydrology, Nitrogen Fluxes, and Combined Sewer Overflows in the Baltimore, MD and Washington, DC area

    Science.gov (United States)

    Despite the increasing use of urban stormwater green infrastructure (SGI), including detention ponds and rain gardens, few studies have quantified the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the effects of SGI, ...

  15. Watershed Scale Impacts of Stormwater Green Infrastructure on Hydrology, Nitrogen Fluxes, and Combined Sewer Overflows in the Baltimore, MD and Washington, DC area

    Science.gov (United States)

    Despite the increasing use of urban stormwater green infrastructure (SGI), including detention ponds and rain gardens, few studies have quantified the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the effects of SGI, ...

  16. Procedure and assessment of cumulative environmental effects Sameiginlegt mat á umhverfisáhrifum

    Directory of Open Access Journals (Sweden)

    Margrét Vala Kristjánsdóttir

    2011-12-01

    Full Text Available This paper deals with a provision in Article 5.2 of the Icelandic Act on Environmental Impact Assessment (EIA, No. 106/2000 that allows for a special procedure of joint EIA of two or more associated projects. Its main aim is to ensure that the overall assessment of environmental effects is taken into account before decisions are made. This provision has raised questions in relation to its scope and applicability. The provision´s origin, substance and application are analysed as well as its conformity to Directive 85/337/EEC as it has been introduced into the EEA Agreement. The paper concludes that administrative implementation has clarified certain aspects, including the legal conditions for its application. However, the application of the provision raises questions as to whether its aim may be achieved by a less onerous procedure; in line with Directive 85/337/EEC as interpreted by the European Commission.Í greininni er fjallað um ákvæði um sameiginlegt mat á umhverfisáhrifum í 2. mgr. 5. gr. laga nr. 106/2000 um mat á umhverfisáhrifum. Meginmarkmið ákvæðisins er að upplýsa um heildaráhrif framkvæmda á umhverfið áður en ákvarðanir um þær eru teknar. Vegna álitaefna sem upp hafa komið í tengslum við framkvæmd ákvæðisins er í greininni leitast við að skýra tilurð þess og efni með hliðsjón af lögskýringargögnum, framkvæmd þess og reglum tilskipunar 85/337/EBE eins og hún hefur verið tekin upp í EES-samninginn. Í greininni er komist að þeirri niðurstöðu að skilyrði fyrir beitingu ákvæðisins hafi skýrst í framkvæmd. Framkvæmdin veki jafnframt spurningar um hvort ná megi markmiðum ákvæðisins jafn vel, með einfaldari leiðum sem samræmast tilskipun 85/337/EBE eins og hún hefur verið skýrð af framkvæmdastjórn Evrópusambandsins.

  17. Density cumulant functional theory from a unitary transformation: N-representability, three-particle correlation effects, and application to O{sub 4}{sup +}

    Energy Technology Data Exchange (ETDEWEB)

    Sokolov, Alexander Yu., E-mail: asokolov@uga.edu; Schaefer, Henry F. [Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602 (United States); Kutzelnigg, Werner [Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, D-44780 Bochum (Germany)

    2014-08-21

    A new approach to density cumulant functional theory is developed that derives density cumulant N-representability conditions from an approximate Fock space unitary transformation. We present explicit equations for the third- and fourth-order two-particle cumulant N-representability, as well as the second-order contributions that depend on the connected three-particle density cumulant. These conditions are used to formulate the ODC-13 method and the non-iterative (λ{sub 3}) correction that employ an incomplete description of the fourth-order two-particle cumulant N-representability and the second-order three-particle correlation effects, respectively. We perform an analysis of the ODC-13 N-representability description for the dissociation of H{sub 2} and apply the ODC-13 method and the (λ{sub 3}) correction to diatomic molecules with multiple bond character and the symmetry-breaking tetraoxygen cation (O{sub 4}{sup +}). For the O{sub 4}{sup +} molecule, the vibrational frequencies of the ODC-13(λ{sub 3}) method do not exhibit spatial symmetry breaking and are in a good agreement with the recent infrared photodissociation experiment. We report the O{sub 4}{sup +} equilibrium structure, harmonic frequencies, and dissociation energy computed using ODC-13(λ{sub 3}) with a diffuse, core-correlated aug-cc-pCVTZ basis set.

  18. Modeling the Effects of Onsite Wastewater Treatment Systems on Nitrate Loads Using SWAT in an Urban Watershed of Metropolitan Atlanta.

    Science.gov (United States)

    Hoghooghi, Nahal; Radcliffe, David E; Habteselassie, Mussie Y; Jeong, Jaehak

    2017-05-01

    Onsite wastewater treatment systems (OWTSs) can be a source of nitrogen (N) pollution in both surface and ground waters. In metropolitan Atlanta, GA, >26% of homes are on OWTSs. In a previous article, we used the Soil Water Assessment Tool to model the effect of OWTSs on stream flow in the Big Haynes Creek Watershed in metropolitan Atlanta. The objective of this study was to estimate the effect of OWTSs, including failing systems, on nitrate as N (NO-N) load in the same watershed. Big Haynes Creek has a drainage area of 44 km with mainly urban land use (67%), and most of the homes use OWTSs. A USGS gauge station where stream flow was measured daily and NO-N concentrations were measured monthly was used as the outlet. The model was simulated for 12 yr. Overall, the model showed satisfactory daily stream flow and NO-N loads with Nash-Sutcliffe coefficients of 0.62 and 0.58 for the calibration period and 0.67 and 0.33 for the validation period at the outlet of the Big Haynes Watershed. Onsite wastewater treatment systems caused an average increase in NO-N load of 23% at the watershed scale and 29% at the outlet of a subbasin with the highest density of OWTSs. Failing OWTSs were estimated to be 1% of the total systems and did not have a large impact on stream flow or NO-N load. The NO-N load was 74% of the total N load in the watershed, indicating the important effect of OWTSs on stream loads in this urban watershed. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  19. Effects of polders on the course of floods in the watershed of the Tichá Orlice river

    Directory of Open Access Journals (Sweden)

    Vladimír Pavlík

    2008-01-01

    Full Text Available Polders show an important water-management function in the flood-control protection of watersheds. The course of actual floods in recent decades and effects of the water works on flood flows have proved the suitability of the construction within integrated flood-control measures in particular watersheds of the Czech Republic. To determine the transformation effect of flood-control measures in watersheds mathematical modelling is an important method, which is used not only in the preparation and design of retention areas but also in dealing with the flood protection of towns and villages. Easy verification of other measures in watersheds is also useful. Their implementation can be thus prepared for the future or it is possible to back off the intentions. In our case, a fact is advantageous that the model is ope­ra­ted in the workplace of the Elbe Basin water-management dispatching centre, which is compatible with assessed polders in the partial Elbe watershed, namely in the Tichá Orlice watershed and its partial Třebovka watershed. The polders assessed are situated on the Třebovka stream, which is the lar­gest tributary of the Tichá Orlice river. These dry reservoirs and the increased protective function of the Hvězda pond affect runoff from about 80 km2. Within research activities, possibilities were studied to obtain necessary retention areas in existing small water reservoirs. It became evident that the only rea­lis­tic solution was to increase protective functions of the pond Hvězda. Its present total retention space of 1.4 million m3 can be increased only by 0.35 million m3, however, in combination with the sophisticated lay-out of a new emergency spillway and outlet the whole retention space can be used much more effectively. To obtain other retention areas localities were found out in the whole upper watershed of the Třebovka stream, which fulfilled requirements for placing the adequate capacity of polders. Subsequent

  20. Delineation and Characterization of Furnace Brook Watershed in Marshfield, Massachusetts: A Study of Effects upon Conjunctive Water Use within a Watershed

    Science.gov (United States)

    Croll, E. D.; Enright, R.

    2012-12-01

    surveys and meteorological data. Early data analysis indicated that the stream behaved in an anomalous manner decreasing in discharge with downstream flow despite normal precipitation inputs. The behavior within this particular watershed appeared to be influenced by four primary factors resulting in the stream "running dry" during the June-August period. These factors included: (1) A losing gradient induced by well pumping (2) Obstructions to stream flow reduced contribution from upper reaches to lower reaches (3) A highly anisotropic layer of lower conductivity material regulated infiltration rates and (4) Evapotranspiration effects are such that during this period the basin is in a deficit situation even without additional losses. Additionally, relationships between well pumping and decreasing discharge, seepage flux loss rates and hydraulic gradients have demonstrated that even within humid region watersheds it cannot be assumed aquifer recharge is sufficient to avoid conflict between surface water protection and ground water utilization. Timing of precipitation events combined with geological governance of aquifer recharge play critical roles in managing the conjunctive use of water resources and cannot be assumed to have a negligible effect, even within relatively humid regions.

  1. Effects of watershed land-cover on the biogeochemical properties of estuarine tidal flat sediments: A test in a densely-populated subtropical island

    Science.gov (United States)

    Morita, Akiko; Touyama, Shouji; Kuwae, Tomohiro; Nishimura, Osamu; Sakamaki, Takashi

    2017-01-01

    The effects of watershed land cover on the biogeochemical properties of estuarine tidal flat sediment were examined in estuarine tidal flats of 16 watersheds in a densely populated, subtropical island of Japan. Despite the small sizes of the watersheds (human nutrient inputs significantly increase algae-derived deposits in estuaries with relatively more developed watersheds. The δ13C of particulate organic matter (POM) was negatively related to watershed forest cover. This suggests that terrestrially derived-origin POM deposits are substantial in the estuaries connected to watersheds with relatively high forest cover. However, the chemical properties of tidal flat sediment were not related to chemical indicators of POM in the base flow. We hypothesize that substantial terrestrially derived POM is discharged to estuaries of high-forest-cover watersheds during high flow, and this partially controls the chemical properties of estuarine sediments. Our results demonstrate that the chemical properties of estuarine tidal flats are associated with watershed land cover, and that the dominant processes controlling estuarine sediment properties differ among watersheds depending on land cover composition.

  2. Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams

    Science.gov (United States)

    Ciparis, S.; Iwanowicz, L.R.; Voshell, J.R.

    2012-01-01

    Application of manures from animal feeding operations (AFOs) as fertilizer on agricultural land can introduce nutrients and hormones (e.g. estrogens) to streams. A landscape-scale study was conducted in the Shenandoah River watershed (Virginia, USA) in order to assess the relationship between densities of AFOs in watersheds of agricultural streams and in-stream nutrient concentrations and estrogenic activity. The effect of wastewater treatment plants (WWTPs) on nutrients and estrogenic activity was also evaluated. During periods of high and low flow, dissolved inorganic nitrogen (DIN) and orthophosphate (PO 4-P) concentrations were analyzed and estrogens/estrogenic compounds were extracted and quantified as17??-estradiol equivalents (E2Eq) using a bioluminescent yeast estrogen screen. Estrogenic activity was measurable in the majority of collected samples, and 20% had E2Eq concentrations >1ng/L. Relatively high concentrations of DIN (>1000??g/L) were also frequently detected. During all sampling periods, there were strong relationships between watershed densities of AFOs and in-stream concentrations of DIN (R 2=0.56-0.81) and E2Eq (R 2=0.39-0.75). Relationships between watershed densities of AFOs and PO 4-P were weaker, but were also significant (R 2=0.27-0.57). When combined with the effect of watershed AFO density, streams receiving WWTP effluent had higher concentrations of PO 4-P than streams without WWTP discharges, and PO 4-P was the only analyte with a consistent relationship to WWTPs. The results of this study suggest that as the watershed density of AFOs increases, there is a proportional increase in the potential for nonpoint source pollution of agricultural streams and their receiving waters by nutrients, particularly DIN, and compounds that can cause endocrine disruption in aquatic organisms. ?? 2011 Elsevier B.V.

  3. The cumulative effect of assisted reproduction procedures on placental development and epigenetic perturbations in a mouse model.

    Science.gov (United States)

    de Waal, Eric; Vrooman, Lisa A; Fischer, Erin; Ord, Teri; Mainigi, Monica A; Coutifaris, Christos; Schultz, Richard M; Bartolomei, Marisa S

    2015-12-15

    Assisted reproductive technologies (ART) are associated with several complications including low birth weight, abnormal placentation and increased risk for rare imprinting disorders. Indeed, experimental studies demonstrate ART procedures independent of existing infertility induce epigenetic perturbations in the embryo and extraembryonic tissues. To test the hypothesis that these epigenetic perturbations persist and result in adverse outcomes at term, we assessed placental morphology and methylation profiles in E18.5 mouse concepti generated by in vitro fertilization (IVF) in two different genetic backgrounds. We also examined embryo transfer (ET) and superovulation procedures to ascertain if they contribute to developmental and epigenetic effects. Increased placental weight and reduced fetal-to-placental weight ratio were observed in all ART groups when compared with naturally conceived controls, demonstrating that non-surgical embryo transfer alone can impact placental development. Furthermore, superovulation further induced overgrowth of the placental junctional zone. Embryo transfer and superovulation defects were limited to these morphological changes, as we did not observe any differences in epigenetic profiles. IVF placentae, however, displayed hypomethylation of imprinting control regions of select imprinted genes and a global reduction in DNA methylation levels. Although we did not detect significant differences in DNA methylation in fetal brain or liver samples, rare IVF concepti displayed very low methylation and abnormal gene expression from the normally repressed allele. Our findings suggest that individual ART procedures cumulatively increase placental morphological abnormalities and epigenetic perturbations, potentially causing adverse neonatal and long-term health outcomes in offspring.

  4. Behavior and finite-size effects of the sixth order cumulant in the three-dimensional Ising universality class

    CERN Document Server

    Pan, Xue; Wu, Yuan-Fang

    2016-01-01

    The high-order cumulants of conserved charges are suggested to be sensitive observables to search for the critical point of Quantum Chromodynamics (QCD). The order has been calculated to the sixth one at experiments. The corresponding theoretical studies on the sixth order cumulant are necessary. Based on the universality of the critical behavior, we study the temperature dependence of the sixth order cumulant of the order parameter using the parametric representation of the three-dimensional Ising model, which is expected to be in the same universality class with QCD. The density plot of the sign of the sixth order cumulant is shown on the temperature and external magnetic field plane. We found that when the critical point is approached from the crossover side, the sixth order cumulant is negative. Qualitatively, the trend is similar to the result of Monte Carlo simulation on a finite-size system. Quantitatively, the temperature of the sign change is different. Through Monte Carlo simulation of the Ising mod...

  5. Estimating the cumulative effects of the nature-based tourism in a coastal dolphin population from southern Kenya

    Science.gov (United States)

    Pérez-Jorge, Sergi; Louzao, Maite; Oro, Daniel; Pereira, Thalia; Corne, Chloe; Wijtten, Zeno; Gomes, Inês; Wambua, John; Christiansen, Fredrik

    2017-06-01

    Due to the growth of nature-based tourism worldwide, behavioural studies are needed to assess the impact of this industry on wildlife populations and understand their short-term effect. Tourism impact on dolphin populations remain poorly documented in developing countries. This study investigates the effects of nature-based tourism on the behaviour of the Indo-Pacific bottlenose dolphins (Tursiops aduncus) in southern Kenya. We used Markov chain models to estimate transition probabilities between behavioural states in the presence and absence of tourist boats, and assess the overall behavioural budgets. Based on these data and the tourism intensity in the area, we quantified the potential tourist boat disturbance over the period 2006-2013. Our results demonstrated that tourist boat interactions affected dolphins' behavioural budgets, with a significant decrease in the overall amount of time travelling and an increase in diving. The average duration of travelling and resting decreased significantly in the presence of boats. Although the cumulative tourism exposure was not significant for the dolphin population at their current levels, these impacts should be taken into consideration with the potential tourism growth in the area. This is particularly important if tourism reaches periods of high intensity, as we have shown that these periods could have a significant impact for the species, particularly where home-range and core areas are highly overlap by this activity. Understanding the effect of human disturbance variations from previous years may help to predict the consequences on dolphin populations, towards achieving a more ecological and economic sustainability of the activity.

  6. Cumulative effects of anodal and priming cathodal tDCS on pegboard test performance and motor cortical excitability.

    Science.gov (United States)

    Christova, Monica; Rafolt, Dietmar; Gallasch, Eugen

    2015-01-01

    Transcranial direct current stimulation (tDCS) protocols applied over the primary motor cortex are associated with changes in motor performance. This transcranial magnetic stimulation (TMS) study examines whether cathodal tDCS prior to motor training, combined with anodal tDCS during motor training improves motor performance and off-line learning. Three study groups (n=36) were trained on the grooved pegboard test (GPT) in a randomized, between-subjects design: SHAM-sham stimulation prior and during training, STIM1-sham stimulation prior and atDCS during training, STIM2-ctDCS stimulation prior and atDCS during training. Motor performance was assessed by GPT completion time and retested 14 days later to determine off-line learning. Cortical excitability was assessed via TMS at baseline (T0), prior training (T1), after training (T2), and 60 min after training (T3). Motor evoked potentials (MEP) were recorded from m. abductor pollicis brevis of the active left hand. GPT completion time was reduced for both stimulated groups compared to SHAM. For STIM2 this reduction in time was significantly higher than for STIM1 and further off-line learning occurred after STIM2. After ctDCS at T1, MEP amplitude and intracortical facilitation was decreased and intracortical inhibition was increased. After atDCS at T2, an opposite effect was observed for STIM1 and STIM2. For STIM2 these neuromodulatory effects were retained until T3. It is concluded that application of atDCS during the training improves pegboard performance and that additional priming with ctDCS has a positive effect on off-line learning. These cumulative behavioral gains were indicated by the preceding neuromodulatory changes.

  7. Cumulative Effects of Climate Warming and Other Human Activities on Freshwaters of Arctic and Subarctic North America

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, David W. [Univ. of Alberta, Edmonton, AB (Canada).Dept. of Biological Sciences; Smol, John P. [Queen' s Univ., Kingston, ON (Canada). Dept. of Biology

    2006-06-15

    Despite their generally isolated geographic locations, the freshwaters of the north are subjected to a wide spectrum of environmental stressors. High-latitude regions are especially sensitive to the effects of recent climatic warming, which have already resulted in marked regime shifts in the biological communities of many Arctic lakes and ponds. Important drivers of these limnological changes have included changes in the amount and duration of snow and ice cover, and, for rivers and lakes in their deltas, the frequency and extent of spring floods. Other important climate-related shifts include alterations in evaporation and precipitation ratios, marked changes in the quality and quantity of lake and river water inflows due to accelerated glacier and permafrost melting, and declining percentages of precipitation that falls as snow. The depletion of stratospheric ozone over the north, together with the clarity of many Arctic lakes, renders them especially susceptible to damage from ultraviolet radiation. In addition, the long-range atmospheric transport of pollutants, coupled with the focusing effects of contaminant transport from biological vectors to some local ecosystems (e.g., salmon nursery lakes, ponds draining seabird colonies) and biomagnification in long food chains, have led to elevated concentrations of many persistent organic pollutants (e.g., insecticides, which have never been used in Arctic regions) and other pollutants (e.g., mercury). Rapid development of gas and oil pipelines, mining for diamonds and metals, increases in human populations, and the development of all-season roads, seaports, and hydroelectric dams will stress northern aquatic ecosystems. The cumulative effects of these stresses will be far more serious than those caused by changing climate alone.

  8. The Choptank Watershed Wetland Conservation Effects Assessment Project: Monitoring the Delivery of Wetland Services across the Landscape

    Science.gov (United States)

    The Choptank Watershed Wetland Conservation Effects Assessment Project (CEAP) brings together an interdisciplinary group of experts and resources from multiple federal agencies and the University of Maryland to assess the ability of “natural,” restored, and prior-converted wetlands on cropland to im...

  9. Effectiveness of Integrated Best Management Practices on Mitigation of Atrazine and Metolachlor in an Agricultural Lake Watershed.

    Science.gov (United States)

    Lizotte, Richard; Locke, Martin; Bingner, Ronald; Steinriede, R Wade; Smith, Sammie

    2017-04-01

    The study examined the influence of land-use (cropping patterns) and integrated agricultural best management practices (BMPs) on spring herbicide levels in an agricultural watershed. Atrazine and metolachlor were applied for weed control during spring of 1998-2002, 2005, and 2007-2013. Watershed-wide mass of applied herbicides ranged from 12.7 to 209.2 g atrazine and 10.9-302.2 g metolachlor with greatest application during 1998, 2009-2010 (atrazine) and 2007-2013 (metolachlor). Spring herbicide concentrations in Beasley Lake water ranged from below detection to 3.54 μg atrazine/L and 3.01 μg metolachlor/L. Multiple linear regression analyses with cropping patterns, BMPs, rainfall and time as independent variables, showed atrazine applications were associated with increases in cotton acreage and quail buffer, while metolachlor applications increased over time. Multiple linear regressions showed lake atrazine concentrations were associated with conservation tillage, rainfall, and corn, while lake metolachlor concentrations were associated with the cumulative metolachlor application and sediment retention pond installation.

  10. Watershed characteristics and water-quality trends and loads in 12 watersheds in Gwinnett County, Georgia

    Science.gov (United States)

    Joiner, John K.; Aulenbach, Brent T.; Landers, Mark N.

    2014-01-01

    nitrogen, total phosphorus, total organic carbon, total lead, total zinc, total suspended solids, and suspended-sediment concentrations increased with increasing discharge at all watersheds. Specific conductance, however, decreased during stormflow at all watersheds, and total dissolved solids concentrations decreased during stormflow at a few of the watersheds. Total suspended solids and suspended-sediment concentrations typically were two orders of magnitude higher in stormflow samples, turbidities were about 1.5 orders of magnitude higher, total phosphorus and total zinc were about one order of magnitude higher, and total ammonia plus organic nitrogen, total nitrogen, total organic carbon, and total lead were about twofold higher than in base-flow samples. Seasonal patterns and long-term trends in flow-adjusted water-quality concentrations were identified for five representative constituents—total nitrogen, total phosphorus, total zinc, total dissolved solids, and total suspended solids. Seasonal patterns for all five constituents were fairly similar, with higher concentrations in the summer and lower concentrations in the winter. Significant linear long-term trends in stormflow composite concentrations were identified for 36 of the 60 constituent-watershed combinations (5 constituents multiplied by 12 watersheds) for the period of record through water year 2011. Significant trends typically were decreasing for total nitrogen, total phosphorus, total suspended solids, and total zinc and increasing for total dissolved solids. Total dissolved solids and total suspended solids trends had the largest magnitude changes per year. Stream water loads were estimated for 10 water-quality constituents. These estimates represent the cumulative effects of watershed characteristics, hydrologic processes, biogeochemical processes, climatic variability, and human influences on watershed water quality. Yields, in load per unit area, were used to compare loads from watersheds with

  11. Cumulative effect of disinfection procedures on microhardness and tridimensional stability of a poly(methyl methacrylate) denture base resin.

    Science.gov (United States)

    Sartori, Evandro Afonso; Schmidt, Caroline Bom; Mota, Eduardo Gonçalves; Hirakata, Luciana Mayumi; Shinkai, Rosemary Sadami Arai

    2008-08-01

    Microwave irradiation has been used for disinfection of dentures instead of chemical solutions; yet, its effect on resin properties after repeated procedures still is unclear. This study evaluated the cumulative effect of two disinfection methods on Knoop microhardness and tridimensional stability of a poly(methyl methacrylate) denture base resin. For the microhardness measurement, 24-resin discs received mechanical polishing and were submitted to the following treatments: (1) control (no disinfection), (2) chemical disinfection (immersion in 100ppm chloride solution for 24h), or (3) microwave disinfection (irradiation at 690 W for 6 min). Disinfection procedures were performed twice (T1, T2) with a 7-day interval. Knoop microhardness was recorded after polishing (T0) and after T1 and T2. For the dimensional stability test (measured by the adaptation of the denture bases), 36-maxillary denture bases were obtained from type III dental stone casts duplicated from a metallic master model and submitted to the disinfection treatment. Adaptation of denture bases was measured at baseline (T0) and after T1 and T2 by weighing a vinyl polysiloxane film reproducing the gap between resin base and master model. Data were analyzed by ANOVA GLM for repeated measures and Bonferroni's test, alpha = 0.05. Knoop microhardness was not modified by any disinfection procedure but decreased over time. Denture resin bases submitted to microwave disinfection had gradual increase of distortion over time, while bases immersed in chloride solution did not differ from the control group and remained dimensionally stable from T1 to T2.

  12. Effects of impervious area and BMP implementation and design on storm runoff and water quality in eight small watersheds

    Science.gov (United States)

    Aulenbach, Brent T.; Landers, Mark N.; Musser, Jonathan W.; Painter, Jaime A.

    2017-01-01

    The effects of increases in effective impervious area (EIA) and the implementation of water quality protection designed detention pond best management practices (BMPs) on storm runoff and stormwater quality were assessed in Gwinnett County, Georgia, for the period 2001-2008. Trends among eight small watersheds were compared, using a time trend study design. Significant trends were detected in three storm hydrologic metrics and in five water quality constituents that were adjusted for variability in storm characteristics and climate. Trends in EIA ranged from 0.10 to 1.35, and changes in EIA treated by BMPs ranged from 0.19 to 1.32; both expressed in units of percentage of drainage area per year. Trend relations indicated that for every 1% increase in watershed EIA, about 2.6, 1.1, and 1.5% increases in EIA treated by BMPs would be required to counteract the effects of EIA added to the watersheds on peak streamflow, stormwater yield, and storm streamflow runoff, respectively. Relations between trends in EIA, BMP implementation, and water quality were counterintuitive. This may be the result of (1) changes in constituent inputs in the watersheds, especially downstream of areas treated by BMPs; (2) BMPs may have increased the duration of stormflow that results in downstream channel erosion; and/or (3) spurious relationships between increases in EIA, BMP implementation, and constituent inputs with development rates.

  13. COST-EFFECTIVE ALLOCATION OF WATERSHED MANAGEMENT PRACTICES USING A GENETIC ALGORITHM

    Science.gov (United States)

    Implementation of conservation programs are perceived as being crucial for restoring and protecting waters and watersheds from non-point source pollution. Success of these programs depends to a great extent on planning tools that can assist the watershed management process. Here-...

  14. Effects of timber harvesting on the lag time of Caspar Creek watershed

    Science.gov (United States)

    Karen Hardison Sendek

    1985-01-01

    Abstract - Hydrograph lag time was analyzed to determine changes after road construction and after selective, tractor-yarded logging in a Caspar Creek watershed, Mendocino County, California. The paired watershed technique was used. Hydrograph lag time for each storm was the time separation between the midpoint of precipitation and the time coordinate of the runoff...

  15. Watershed model calibration to the base flow recession curve with and without evapotranspiration effects

    Science.gov (United States)

    Jepsen, S. M.; Harmon, T. C.; Shi, Y.

    2016-04-01

    Calibration of watershed models to the shape of the base flow recession curve is a way to capture the important relationship between groundwater discharge and subsurface water storage in a catchment. In some montane Mediterranean regions, such as the midelevation Providence Creek catchment in the southern Sierra Nevada of California (USA), nearly all base flow recession occurs after snowmelt, and during this time evapotranspiration (ET) usually exceeds base flow. We assess the accuracy to which watershed models can be calibrated to ET-dominated base flow recession in Providence Creek, both in terms of fitting a discharge time-series and realistically capturing the observed discharge-storage relationship for the catchment. Model parameters estimated from calibrations to ET-dominated recession are compared to parameters estimated from reference calibrations to base flow recession with ET-effects removed ("potential recession"). We employ the Penn State Integrated Hydrologic Model (PIHM) for simulations of base flow and ET, and methods that are otherwise general in nature. In models calibrated to ET-dominated recession, simulation errors in ET and the targeted relationship for recession (-dQ/dt versus Q) contribute substantially (up to 57% and 46%, respectively) to overestimates in the discharge-storage differential, defined as d(lnQ)/dS, relative to that derived from water flux observations. These errors result in overestimates of deep-subsurface hydraulic conductivity in models calibrated to ET-dominated recession, by up to an order of magnitude, relative to reference calibrations to potential recession. These results illustrate a potential opportunity for improving model representation of discharge-storage dynamics by calibrating to the shape of base flow recession after removing the complicating effects of ET.

  16. Assessing the effectiveness of winter cover crop on nitrate reduction in two-paired sub-basins on the Coastal Plain of the Chesapeake Bay Watershed

    Science.gov (United States)

    Lee, S.; Yeo, I. Y.; Sadeghi, A. M.; Mccarty, G.; Hively, W. D.; Lang, M. W.

    2014-12-01

    Best management practices (BMPs) have been widely adopted to improve water quality throughout the Chesapeake Bay Watershed (CBW). Winter cover crops (WCC) use has been highlighted for the reduction of nitrate leaching over the fallow season. Although various WCC practices are currently conducted in local croplands, the water quality improvement benefits of WCC have not been studied thoroughly at the watershed scale. The objective of this study is to assess the long-term impacts of WCC on reducing nitrate loadings using a processed-based watershed model, Soil and Water Assessment Tool (SWAT). Remote sensing based estimates of WCC biomass will be used to calibrate plant growth processes of SWAT and its nutrient cycling. The study will be undertaken in two-paired agricultural watersheds in the Coastal Plain of CBW. Multiple WCC practice scenarios will be prepared to investigate how nitrate loading varies with crop species, planting dates, and implementation areas. The performance of WCC on two-paired watersheds will be compared in order to understand the effects of different watershed characteristics on nitrate uptake by crops. The results will demonstrate the nitrate reduction efficiency of different WCC practices and identify the targeting area for WCC implementation at the watershed scale. This study will not only integrate remote sensing data into the physically based model but also extend our understandings of WCC functions. This will provide key information for effective conservation decision making. Key words: Water quality, Chesapeake Bay Watershed, Winter Cover Crop, Soil and Water Assessment Tool (SWAT)

  17. Inequality in the Scientific Community: The Effects of Cumulative Advantage among Social Scientists and Humanities Scholars in Korea

    Science.gov (United States)

    Kim, Keuntae; Kim, Jong-Kil

    2017-01-01

    The primary goal of this paper is to provide a balanced perspective for understanding inequality in research productivity among Korean scholars in humanities and social sciences. Specifically, we examine cumulative advantage over the careers of a sample of Korean social scientists and humanities scholars (N = 8933). Descriptive analyses indicated…

  18. Hydrologic response to stormwater control measures in urban watersheds

    Science.gov (United States)

    Bell, Colin D.; McMillan, Sara K.; Clinton, Sandra M.; Jefferson, Anne J.

    2016-10-01

    Stormwater control measures (SCMs) are designed to mitigate deleterious effects of urbanization on river networks, but our ability to predict the cumulative effect of multiple SCMs at watershed scales is limited. The most widely used metric to quantify impacts of urban development, total imperviousness (TI), does not contain information about the extent of stormwater control. We analyzed the discharge records of 16 urban watersheds in Charlotte, NC spanning a range of TI (4.1-54%) and area mitigated with SCMs (1.3-89%). We then tested multiple watershed metrics that quantify the degree of urban impact and SCM mitigation to determine which best predicted hydrologic response across sites. At the event time scale, linear models showed TI to be the best predictor of both peak unit discharge and rainfall-runoff ratios across a range of storm sizes. TI was also a strong driver of both a watershed's capacity to buffer small (e.g., 1-10 mm) rain events, and the relationship between peak discharge and precipitation once that buffering capacity is exceeded. Metrics containing information about SCMs did not appear as primary predictors of event hydrologic response, suggesting that the level of SCM mitigation in many urban watersheds is insufficient to influence hydrologic response. Over annual timescales, impervious surfaces unmitigated by SCMs and tree coverage were best correlated with streamflow flashiness and water yield, respectively. The shift in controls from the event scale to the annual scale has important implications for water resource management, suggesting that overall limitation of watershed imperviousness rather than partial mitigation by SCMs may be necessary to alleviate the hydrologic impacts of urbanization.

  19. Suburban watershed nitrogen retention: Estimating the effectiveness of stormwater management structures

    Directory of Open Access Journals (Sweden)

    Benjamin J. Koch

    2015-07-01

    Full Text Available Abstract Excess nitrogen (N is a primary driver of freshwater and coastal eutrophication globally, and urban stormwater is a rapidly growing source of N pollution. Stormwater best management practices (BMPs are used widely to remove excess N from runoff in urban and suburban areas, and are expected to perform under a wide variety of environmental conditions. Yet the capacity of BMPs to retain excess N varies; and both the variation and the drivers thereof are largely unknown, hindering the ability of water resource managers to meet water quality targets in a cost-effective way. Here, we use structured expert judgment (SEJ, a performance-weighted method of expert elicitation, to quantify the uncertainty in BMP performance under a range of site-specific environmental conditions and to estimate the extent to which key environmental factors influence variation in BMP performance. We hypothesized that rain event frequency and magnitude, BMP type and size, and physiographic province would significantly influence the experts’ estimates of N retention by BMPs common to suburban Piedmont and Coastal Plain watersheds of the Chesapeake Bay region. Expert knowledge indicated wide uncertainty in BMP performance, with N removal efficiencies ranging from 40%. Experts believed that the amount of rain was the primary identifiable source of variability in BMP efficiency, which is relevant given climate projections of more frequent heavy rain events in the mid-Atlantic. To assess the extent to which those projected changes might alter N export from suburban BMPs and watersheds, we combined downscaled estimates of rainfall with distributions of N loads for different-sized rain events derived from our elicitation. The model predicted higher and more variable N loads under a projected future climate regime, suggesting that current BMP regulations for reducing nutrients may be inadequate in the future.

  20. Potential effects of climate change and variability on watershed biogeochemical processes and water quality in Northeast Asia.

    Science.gov (United States)

    Park, Ji-Hyung; Duan, Lei; Kim, Bomchul; Mitchell, Myron J; Shibata, Hideaki

    2010-02-01

    An overview is provided of the potential effects of climate change on the watershed biogeochemical processes and surface water quality in mountainous watersheds of Northeast (NE) Asia that provide drinking water supplies for large populations. We address major 'local' issues with the case studies conducted at three watersheds along a latitudinal gradient going from northern Japan through the central Korean Peninsula and ending in southern China. Winter snow regimes and ground snowpack dynamics play a crucial role in many ecological and biogeochemical processes in the mountainous watersheds across northern Japan. A warmer winter with less snowfall, as has been projected for northern Japan, will alter the accumulation and melting of snowpacks and affect hydro-biogeochemical processes linking soil processes to surface water quality. Soils on steep hillslopes and rich in base cations have been shown to have distinct patterns in buffering acidic inputs during snowmelt. Alteration of soil microbial processes in response to more frequent freeze-thaw cycles under thinner snowpacks may increase nutrient leaching to stream waters. The amount and intensity of summer monsoon rainfalls have been increasing in Korea over recent decades. More frequent extreme rainfall events have resulted in large watershed export of sediments and nutrients from agricultural lands on steep hillslopes converted from forests. Surface water siltation caused by terrestrial export of sediments from these steep hillslopes is emerging as a new challenge for water quality management due to detrimental effects on water quality. Climatic predictions in upcoming decades for southern China include lower precipitation with large year-to-year variations. The results from a four-year intensive study at a forested watershed in Chongquing province showed that acidity and the concentrations of sulfate and nitrate in soil and surface waters were generally lower in the years with lower precipitation, suggesting year

  1. A Paired watershed Evaluation of Agroforestry effects on Water Quality on a Corn/Soybean Rotation

    Science.gov (United States)

    Udawatta, Ranjith; Jose, Shibu; Garrett, Harold

    2015-04-01

    Rigorous long-term scientific studies confirming environmental benefits from the use of agroforestry practices are limited and thus limit the adoption of agroforestry practices throughout the world. The objective of the study was to examine non point source pollution (NPSP) reduction by agroforestry buffers in row-crop watersheds. The study consists of three watersheds in a paired watershed design in Knox County, Missouri, USA. Watersheds were established in 1991 and treatments of agroforestry (trees+grass) and grass buffers were established on two watersheds in 1997 after a 7-year calibration period. Runoff water samples were analyzed for sediment, total nitrogen (TN) and total phosphorus (TP) for the 2009 to 2010 period. Results indicated that agroforestry and grass buffers on row crop watersheds significantly reduce runoff, sediment, TN, and TP losses to streams. Buffers in association with row crop management reduced runoff by 26% during the study period as compared to the control treatments. Average sediment loss for row crop management and buffer watersheds was 14.8 and 9.7 kg ha-1 yr-1 respectively. On average, grass and agroforestry buffers reduced sediment, TN, and TP losses by 32, 42, and 46% compared to the control treatments. These differences could in part be attributed to the differences in management, soils, and landscape features. Results from this study strongly indicate that agroforestry and grass buffers can be implemented to reduce NPSP to water bodies while improving land value and environmental quality.

  2. Empirical assessment of effects of urbanization on event flow hydrology in watersheds of Canada's Great Lakes-St Lawrence basin

    Science.gov (United States)

    Trudeau, M. P.; Richardson, Murray

    2016-10-01

    We conducted an empirical hydrological analysis of high-temporal resolution streamflow records for 27 watersheds within 11 river systems in the Greater Toronto Region of the Canadian Great Lakes basin. Our objectives were to model the event-scale flow response of watersheds to urbanization and to test for scale and threshold effects. Watershed areas ranged from 37.5 km2 to 806 km2 and urban percent land cover ranged from less than 0.1-87.6%. Flow records had a resolution of 15-min increments and were available over a 42-year period, allowing for detailed assessment of changes in event-scale flow response with increasing urban land use during the post-freshet period (May 26 to November 15). Empirical statistical models were developed for flow characteristics including total runoff, runoff coefficient, eightieth and ninety-fifth percentile rising limb event runoff and mean rising limb event acceleration. Changes in some of these runoff metrics began at very low urban land use (literature recommendations for spatially distributed low impact urban development techniques; measures would be needed throughout the urbanized area of a watershed to dampen event-scale hydrologic responses to urbanization. Additional research is warranted into event-scale hydrologic trends with urbanization in other regions, in particular rising limb event flow accelerations.

  3. Stable isotope fingerprint of open-water evaporation losses and effective drainage area fluctuations in a subarctic shield watershed

    Science.gov (United States)

    Gibson, J. J.; Reid, R.

    2010-02-01

    SummaryStable isotopes of water, oxygen-18 and deuterium, were measured at biweekly to monthly intervals during the open-water season in a small, headwater lake (Pocket Lake, 4.8 ha) near Yellowknife Northwest Territories, and concurrently in a nearby string-of-lakes watershed (Baker Creek, 137 km 2) situated in the subarctic Precambrian Shield region. As measured in water samples collected over a 12 year period (1997-2008), the levels of evaporative isotopic enrichment in both lake and watershed outflow were differentially offset, and seasonal variations were found in both to be driven by variations in open-water evaporation. Systematic differences measured in the magnitude of the offset between the lake and watershed outflow are interpreted as being caused by changes in the effective drainage area contributing to runoff. Based on the observed and extremely consistent relationship between isotopic compositions of lake water and watershed outflow ( r2 = 0.849, p isotopic signals transferred downstream in a typical shield drainage system within the Mackenzie Basin.

  4. Watershed District

    Data.gov (United States)

    Kansas Data Access and Support Center — Boundaries show on this map are derived from legal descriptions contained in petitions to the Kansas Secretary of State for the creation or extension of watershed...

  5. Watershed Investigations

    Science.gov (United States)

    Bodzin, Alec; Shive, Louise

    2004-01-01

    Investigating local watersheds presents middle school students with authentic opportunities to engage in inquiry and address questions about their immediate environment. Investigation activities promote learning in an investigations interdisciplinary context as students explore relationships among chemical, biological, physical, geological, and…

  6. Assessing Watershed Transport of Atrazine and Nitrate to Evaluate Conservation Practice Effects and Advise Future Monitoring Strategies

    Science.gov (United States)

    O'Donnell, T. Kevin

    2012-01-01

    Continued public support for U.S. taxpayer funded programs aimed at reducing agricultural pollutants depends on clear demonstrations of water quality improvements. The objective of this research was to determine if implementation of agricultural best management practices (BMPs) in the Goodwater Creek Experimental Watershed (GCEW) resulted in changes to atrazine and nitrate (NO3-N) loads during storm events. An additional objective was to estimate future monitoring periods necessary to detect a 5, 10, 20, and 25% reduction in atrazine and NO3-N event load. The GCEW is a 73 km2 watershed located in northcentral Missouri, USA. Linear regressions and Akaike Information Criteria were used to determine if reductions in atrazine and NO3-N event loads occurred as BMPs were implemented. No effects due to any BMP type were indicated for the period of record. Further investigation of event sampling from the long-term GCEW monitoring program indicated errors in atrazine load calculations may be possible due to pre-existing minimum threshold levels used to trigger autosampling and sample compositing. Variation of event loads was better explained by linear regressions for NO3-N than for atrazine. Decommissioning of upstream monitoring stations during the study period represented a missed opportunity to further explain variation of event loads at the watershed outlet. Atrazine requires approximately twice the monitoring period relative to NO3-N to detect future reductions in event load. Appropriate matching of pollutant transport mechanisms with autosampling protocols remains a critical information need when setting up or adapting watershed monitoring networks aimed at detecting watershed-scale BMP effects.

  7. Cumulative Effective Hölder Exponent Based Indicator for Real-Time Fetal Heartbeat Analysis during Labour

    Science.gov (United States)

    Struzik, Zbigniew R.; van Wijngaarden, Willem J.

    We introduce a special purpose cumulative indicator, capturing in real time the cumulative deviation from the reference level of the exponent h (local roughness, Hölder exponent) of the fetal heartbeat during labour. We verify that the indicator applied to the variability component of the heartbeat coincides with the fetal outcome as determined by blood samples. The variability component is obtained from running real time decomposition of fetal heartbeat into independent components using an adaptation of an oversampled Haar wavelet transform. The particular filters used and resolutions applied are motivated by obstetricial insight/practice. The methodology described has the potential for real-time monitoring of the fetus during labour and for the prediction of the fetal outcome, allerting the attending staff in the case of (threatening) hypoxia.

  8. The cumulative effect of smoking at age 50, 60, and 70 on functional ability at age 75

    DEFF Research Database (Denmark)

    Støvring, Nina; Avlund, Kirsten; Schultz-Larsen, Kirsten

    2004-01-01

    AIMS: As elderly people form a steadily growing part of the population in most parts of the world we are in need of knowledge of the influence of modifiable lifestyle factors on functional ability late in life. This study aims to examine the cumulative impact of smoking from age 50 to 70...... on functional ability at age 75. METHODS: 387 men and women born in 1914 and living in seven municipalities in the western part of the County of Copenhagen were followed for 25 years with examinations in 1964, 1974, 1984, and 1989. Associations between smoking and functional ability were examined using multiple...... logistic regression analyses with cumulative smoking as determinant and physical activity, sex, basic school education, and household composition as possible confounders. RESULTS: There is an adverse relation between smoking and functional ability regardless of the time of examination or the ways...

  9. Healthy Watersheds Protection

    Science.gov (United States)

    Jump to main content US EPA United States Environmental Protection Agency Search Search Healthy Watersheds Protection (HWP) Share ... live in a watershed — thus watershed condition is important to everyone. Watersheds exist at different geographic scales, ...

  10. UBIQUITOUS POLLUTANTS FROM CUMULATIVE ...

    Science.gov (United States)

    The occurrence of pharmaceuticals and personal care products (PPCPS) as environmental pollutants is a multifaceted issue whose scope continues to become better delineated since the escalation of concerted attention beginning in the 1980s. PPCPs typically occur as trace environmental pollutants (primarily in surface but also in ground waters) as a result of their widespread, continuous, combined usage in a broad range of human and veterinary therapeutic activities and practices. With respect to the risk-assessment paradigm, the growing body of published work has focused primarily on the origin and occurrence of these substances. Comparatively less is known about human and ecological exposure, and even less about the known or even potential hazards associated with exposure to these anthropogenic substances, many of which are highly bioactive. The continually growing, worldwide importance of freshwater resources underscores the need for ensuring that any aggregate or cumulative impacts on water supplies and resultant potential for human or ecological exposure be minimized. This has prompted the more recent investigations on waste treatment processes for one of the major sources of environmental disposition, namely sewage. Despite the paucity of health effects data for long-term, simultaneous exposure to multiple xenobiotics (particularly PPCPS) at low doses (a major toxicological issue that can be described by the

  11. Spatial Characterization of Riparian Buffer Effects on Sediment Loads from Watershed Systems

    Science.gov (United States)

    Understanding all watershed systems and their interactions is a complex, but critical, undertaking when developing practices designed to reduce topsoil loss and chemical/nutrient transport from agricultural fields. The presence of riparian buffer vegetation in agricultural lands...

  12. Spatial Characterization of Riparian Buffer Effects on Sediment Loads from Watershed Systems

    Science.gov (United States)

    Understanding all watershed systems and their interactions is a complex, but critical, undertaking when developing practices designed to reduce topsoil loss and chemical/nutrient transport from agricultural fields. The presence of riparian buffer vegetation in agricultural lands...

  13. Watershed-scale impacts of stormwater green infrastructure on hydrology, nutrient fluxes, and combined sewer overflows in the mid-Atlantic region.

    Science.gov (United States)

    Pennino, Michael J; McDonald, Rob I; Jaffe, Peter R

    2016-09-15

    Stormwater green infrastructure (SGI), including rain gardens, detention ponds, bioswales, and green roofs, is being implemented in cities across the globe to reduce flooding, combined sewer overflows, and pollutant transport to streams and rivers. Despite the increasing use of urban SGI, few studies have quantified the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the effects of SGI, Washington, DC, Montgomery County, MD, and Baltimore County, MD, were selected based on the availability of data on SGI, water quality, and stream flow. The cumulative impact of SGI was evaluated over space and time by comparing watersheds with and without SGI, and by assessing how long-term changes in SGI impact hydrologic and water quality metrics over time. Most Mid-Atlantic municipalities have a goal of achieving 10-20% of the landscape drain runoff through SGI by 2030. Of these areas, Washington, DC currently has the greatest amount of SGI (12.7% of the landscape drained through SGI), while Baltimore County has the lowest (7.9%). When controlling for watersheds size and percent impervious surface cover, watersheds with greater amounts of SGI have less flashy hydrology, with 44% lower peak runoff, 26% less frequent runoff events, and 26% less variable runoff. Watersheds with more SGI also show 44% less NO3(-) and 48% less total nitrogen exports compared to watersheds with minimal SGI. There was no significant reduction in phosphorus exports or combined sewer overflows in watersheds with greater SGI. When comparing individual watersheds over time, increases in SGI corresponded to non-significant reductions in hydrologic flashiness compared to watersheds with no change in SGI. While the implementation of SGI is somewhat in its infancy in some regions, cities are beginning to have a scale of SGI where there are statistically significant differences in hydrologic patterns and water quality.

  14. Effects of changes in land use and land cover on sediment discharge of runoff in a typical watershed in the hill and gully loess region of northwest China

    Institute of Scientific and Technical Information of China (English)

    Xiaoming ZHANG; Xinxiao YU; Sihong WU; Wenhong CAO

    2008-01-01

    Land use plays a much more important role than other factors, such as climate, soil properties, topo-graphic features, vegetation coverage, human activities and others, in affecting soil erosion and sediment discharge. In order to understand the effects of changes in land use on sediment discharge and to provide a theoretical basis for land use planning, management and ecological restoration, we used the controlled Qiaozidong watershed and the uncontrolled Qiaozixi watershed in the third sub-region of the Loess Plateau as examples and analyzed the effects of land use and land cover on the discharge of sediments. The results show that the impact of land use and land cover on the annual amount of sediment discharge is significant. Compared with the uncontrolled watershed during similar periods, the amount of sediment discharged from the con-trolled watershed was reduced by 44%, 75% and 86%, respectively, in wet, normal and dry years. In the controlled watershed, compared with the period from 1986 to 1994, the amount of sediments discharged was less during the period from 1995 to 2004. The impact of land use and land cover on sediment discharge demonstrated characteristics of seasonal fluctuation. The effects of sediment reduction in the controlled watershed were greater than those in the uncontrolled watershed in May and September. In the con-trolled watershed, the reduction effect coincided with the distribution of rainfall. The amount of discharged flood sediments is closely correlated with rainfall, rainfall intens-ity in a 60 min period and the volume of flood. The rain-storm-runoff process and the rainstorm-sediment discharge process demonstrate that land cover has a strong regulatory and control function in the flood process and sediment discharge in rainstorms. For the controlled water-shed, given the same precipitation frequency distribution, the average amount of sediment discharged during the land use period from 1995 to 2004 was less than that during the

  15. The effects of climate change and extreme wildfire events on runoff erosion over a mountain watershed

    Science.gov (United States)

    Gould, Gregory K.; Liu, Mingliang; Barber, Michael E.; Cherkauer, Keith A.; Robichaud, Peter R.; Adam, Jennifer C.

    2016-05-01

    Increases in wildfire occurrence and severity under an altered climate can substantially impact terrestrial ecosystems through enhancing runoff erosion. Improved prediction tools that provide high resolution spatial information are necessary for location-specific soil conservation and watershed management. However, quantifying the magnitude of soil erosion and its interactions with climate, hydrological processes, and fire occurrences across a large region (>10,000 km2) is challenging because of the large computational requirements needed to capture the fine-scale complexities of the land surface that govern erosion. We apply the physically-based coupled Variable Capacity Infiltration-Water Erosion Prediction Project (VIC-WEPP) model to study how wildfire occurrences can enhance soil erosion in a future climate over a representative watershed in the northern Rocky Mountains - the Salmon River Basin (SRB) in central Idaho. While the VIC model simulates hydrologic processes at larger scales, the WEPP model simulates erosion at the hillslope scale by sampling representative hillslopes. VIC-WEPP model results indicate that SRB streamflow will have an earlier shift in peak flow by one to two months under future climate scenarios in response to a declining snowpack under warming temperatures. The magnitude of peak flow increases with each higher severity fire scenario; and under the highest fire severity, the peak flow is shifted even earlier, exacerbating the effects of climate change. Similarly, sediment yield also increases with higher fire severities for both historical and future climates. Sediment yield is more sensitive to fire occurrence than to climate change by one to two orders of magnitude, which is not unexpected given that our fire scenarios were applied basin wide as worst case scenarios. In reality, fires only occur over portions of the basin in any given year and subsequent years' vegetation regrowth reduces erosion. However, the effects of climate

  16. Effects of the hydraulic conductivity of the matrix/macropore interface on cumulative infiltrations into dual-permeability media

    Science.gov (United States)

    Lassabatere, L.; Peyrard, X.; Angulo-Jaramillo, R.; Simunek, J.

    2009-12-01

    Modeling of water infiltration into the vadose zone is important for better understanding of movement of water-transported contaminants. There is a great need to take into account the soil heterogeneity and, in particular, the presence of macropores or cracks that could generate preferential flow. Several mathematical models have been proposed to describe unsaturated flow through heterogeneous soils. The dual-permeability model (referred to as the 2K model) assumes that flow is governed by Richards equation in both porous regions (matrix and macropores). Water can be exchanged between the two regions following a first-order rate law. Although several studies have dealt with such modeling, no study has evaluated the influence of the hydraulic conductivity of the matrix/macropore interface on water cumulative infiltration. And this is the focus of this study. An analytical scaling method reveals the role of the following main parameters for given boundary and initial conditions: the saturated hydraulic conductivity ratio (R_Ks), the water pressure scale parameter ratio (R_hg), the saturated volumetric water content ratio (R_θs), and the shape parameters of the water retention and hydraulic conductivity functions. The last essential parameter is related to the interfacial hydraulic conductivity (Ka) between the macropore and matrix regions. The scaled 2K flow equations were solved using HYDRUS-1D 4.09 for the specific case of water infiltrating into an initially uniform soil profile and a zero pressure head at the soil surface. A sensitivity of water infiltration was studied for different sets of scale parameters (R_Ks, R_hg, R_θs, and shape parameters) and the scaled interfacial conductivity (Ka). Numerical results illustrate two extreme behaviors. When the interfacial conductivity is zero (i.e., no water exchange), water infiltrates separately into matrix and macropore regions, producing a much deeper moisture front in the macropore domain. In the opposite case

  17. The cumulative effect of three decades of phosphogypsum amendments in reclaimed marsh soils from SW Spain: (226)Ra, (238)U and Cd contents in soils and tomato fruit.

    Science.gov (United States)

    Abril, José-María; García-Tenorio, Rafael; Enamorado, Santiago M; Hurtado, M Dolores; Andreu, Luis; Delgado, Antonio

    2008-09-15

    Phosphogypsum (PG), a by-product of the phosphate fertiliser industries, has been applied as soil amendment to reduce Na saturation in soils, as in the reclaimed marsh area from SW Spain, where available PG has a typical fingerprint of 710+/-40 Bq kg(-1) of (226)Ra, 165+/-15 Bq kg(-1) of (238)U and 2.8+/-0.4 mg kg(-1) of Cd. This work was focussed on the cumulative effects of PG amendments on the enrichment of these pollutants in cultivated soils and plants (Lycopersicum esculentum Mill L.) from the area studied, where PG has been applied since 1978 at recommended rates of 20-25 Mg ha(-1) every 2-3 years. A field experiment was conducted over three years to compare activity concentrations of (226)Ra ((214)Pb) and (238)U ((234)Th) in non-reclaimed soils, reclaimed soils with no additional PG application, and reclaimed soils with two additional PG applications. A non-significant effect of two PG amendments (in three years) was observed when compared with non-amended reclaimed plots. Nevertheless, a significant (p<0.05) enrichment of (226)Ra was observed in the surface horizon (0-30 cm) of reclaimed plots relative to deeper horizons and also when compared with the surface horizon of non-reclaimed soil (p<0.05), thereby revealing the cumulative effect of three decades of PG applications. Furthermore, the effect of a continuous application of PG was studied by analysing soils and tomato fruits from six commercial farms with different cumulative rates of PG applied. Cadmium concentrations in tomatoes, which were one order of magnitude higher than those found in tomatoes from other areas in South Spain, were positively correlated (r = 0.917) with (226)Ra-concentration in soils, which can be considered an accurate index of the cumulative PG rate of each farm.

  18. Long-Term Effects of Prematurity, Cumulative Medical Risk, and Proximal and Distal Social Forces on Individual Differences in Diurnal Cortisol at Young Adulthood.

    Science.gov (United States)

    Winchester, Suzy B; Sullivan, Mary C; Roberts, Mary B; Bryce, Crystal I; Granger, Douglas A

    2017-01-01

    This study examined the effects of prematurity, cumulative medical risk, and proximal and distal social forces on individual differences in the activity of the hypothalamic-pituitary-adrenal (HPA) axis in young adulthood. A prospective sample of 149 infants born healthy preterm (PT; n = 22), sick PT ( n = 93, medical illness, neurological illness, small for gestational age), and full term ( n = 34) was recruited from a Level III neonatal intensive care unit in southern New England between 1985 and 1989 and followed to age 23 years. Cumulative medical risk was indexed across seven assessment waves (spanning 17 years) using medical and neurological health status at birth, toddlerhood (ages 18 and 30 months), childhood (ages 4 and 8 years), and adolescence (ages 12 and 17 years). Distal risk included socioeconomic status (SES) at birth. Proximal social factors were indexed from assessments of the home environment and measures of child vulnerability and maternal self-esteem, involvement, and control style from birth, 4 years, 8 years, and 12 years. At age 23 years, five saliva samples were collected upon awakening, 45 min after waking, 4 hr after waking, 8 hr after waking, and bedtime (later assayed for cortisol). Results reveal effects of cumulative medical risk on the diurnal pattern of HPA axis activity, with moderating effects of SES and proximal social factors. Findings are discussed in terms of implications for contemporary theories related to developmental sensitivity and susceptibility to context and the developmental origins of health and disease theory.

  19. The effectiveness and resilience of phosphorus management practices in the Lake Simcoe watershed, Ontario, Canada

    Science.gov (United States)

    Crossman, J.; Futter, M. N.; Palmer, M.; Whitehead, P. G.; Baulch, H. M.; Woods, D.; Jin, L.; Oni, S. K.; Dillon, P. J.

    2016-09-01

    Uncertainty surrounding future climate makes it difficult to have confidence that current nutrient management strategies will remain effective. This study used monitoring and modeling to assess current effectiveness (% phosphorus reduction) and resilience (defined as continued effectiveness under a changing climate) of best management practices (BMPs) within five catchments of the Lake Simcoe watershed, Ontario. The Integrated Catchment Phosphorus model (INCA-P) was used, and monitoring data were used to calibrate and validate a series of management scenarios. To assess current BMP effectiveness, models were run over a baseline period 1985-2014 with and without management scenarios. Climate simulations were run (2070-2099), and BMP resilience was calculated as the percent change in effectiveness between the baseline and future period. Results demonstrated that livestock removal from water courses was the most effective BMP, while manure storage adjustments were the least. Effectiveness varied between catchments, influenced by the dominant hydrological and nutrient transport pathways. Resilience of individual BMPs was associated with catchment sensitivity to climate change. BMPs were most resilient in catchments with high soil water storage capacity and small projected changes in frozen-water availability and in soil moisture deficits. Conversely, BMPs were less resilient in catchments with larger changes in spring melt magnitude and in overland flow proportions. Results indicated that BMPs implemented are not always those most suited to catchment flow pathways, and a more site-specific approach would enhance prospects for maintaining P reduction targets. Furthermore, BMP resilience to climate change can be predicted from catchment physical properties and present-day hydrochemical sensitivity to climate forcing.

  20. Effects of bait age and prior protein feeding on cumulative time-dependent mortality of Anastrepha ludens (Diptera: Tephritidae) exposed to GF-120 spinosad baits.

    Science.gov (United States)

    Mangan, Robert L

    2009-06-01

    A fruit fly bait to attract and kill adult fruit flies, GF-120, was tested in cages to determine effects of pretreatment diet and bait aging before use on cumulative mortality rates of Mexican fruit fly, Anastrepha ludens (Loew) (Diptera: Tephritidae). Protein-starved and protein-fed, 9-d-old flies both experienced varying overall cumulative mortality at 4, 8, 24, and 48 h. Pretreatment diet had no significant effect on mortality. Overall mortality rates were below 10% for 4 h, 39-43% at 8 h, but mortality in all treatments increased to 89-93% by 24 h, and 99% by 48 h. In a second experiment, GF-120 baits were either freshly prepared or aged for 24 h. Subtreatments consisted of protein-fed and protein-starved flies. The 24-h-aged bait killed significantly more flies at 4 and 8 h than the freshly prepared bait. Protein-starved flies had significantly higher mortality at 4 h and marginally higher mortality at 8 h than protein-fed flies. At 24 and 48 h, there were no significant differences among treatments, and overall morality rose to 99-100% by 48 h. These results may explain differences noted in previous publications in which fruit fly mortality to GF-120 was reported as unusually low as well as reports of bait ineffectiveness for protein-fed flies. The overall impact of any initial repellency of GF-120 seems negligible as judged by overall cumulative mortality at later evaluation times.

  1. Tc-99 m diethylenetriamine-pentaacetic acid (DTPA): is it reliable for assessment of methotrexate-induced cumulative effect on renal filtration in rheumatoid arthritis patients?

    Science.gov (United States)

    Amin, Amr; Effat, Dina; Goher, Nabila; Ramadan, Basma

    2013-12-01

    Methotrexate (MTX) is commonly employed as the initial DMARD used for the treatment of rheumatoid arthritis (RA). We aimed to contribute to the safety profile of MTX by assessing its cumulative effect on renal filtration. A total of 52 RA adult female patients with normal baseline serum creatinine and GFR at the initial diagnosis of the disease were included. Group 1 (G1) included 30 patients (mean age 40.4 ± 4.4 years) on MTX and NSAIDS, while 22 RA patients (mean age 38.5 ± 8.2 years) who received NSAIDs only served as control group (G2). Renal function was assessed by GFR measurement using technetium diethylenetriamine-pentaacetic acid (Tc-99 m DTPA) at a point of the study time corresponding to disease duration. Twenty-one out of thirty (70 %) in G1 showed reduced GFR compared to 6/22 (27.3 %) in G2 (P = 0.007), with 3.3 ± 0.5 % annual reduction in GFR. Reduced GFR in G1 showed significant negative correlation with age (r = -0.396, P = 0.005), MTX cumulative dose (r = -0.263, P = 0.049), MTX-intake duration (r = -0.293, P = 0.031) and NSAIDs-intake duration (r = -0.344, P = 0.014). Low-dose MTX has a slow cumulative effect on renal filtration manifested by GFR reduction overtime that could be monitored by Tc-99 m DTPA.

  2. Quantification of tillage, plant cover, and cumulative rainfall effects on soil surface microrelief by statistical, geostatistical and fractal indices

    Directory of Open Access Journals (Sweden)

    J. Paz-Ferreiro

    2008-07-01

    Full Text Available Changes in soil surface microrelief with cumulative rainfall under different tillage systems and crop cover conditions were investigated in southern Brazil. Surface cover was none (fallow or the crop succession maize followed by oats. Tillage treatments were: 1 conventional tillage on bare soil (BS, 2 conventional tillage (CT, 3 minimum tillage (MT and 4 no tillage (NT under maize and oats. Measurements were taken with a manual relief meter on small rectangular grids of 0.234 and 0.156 m2, throughout growing season of maize and oats, respectively. Each data set consisted of 200 point height readings, the size of the smallest cells being 3×5 cm during maize and 2×5 cm during oats growth periods. Random Roughness (RR, Limiting Difference (LD, Limiting Slope (LS and two fractal parameters, fractal dimension (D and crossover length (l were estimated from the measured microtopographic data sets. Indices describing the vertical component of soil roughness such as RR, LD and l generally decreased with cumulative rain in the BS treatment, left fallow, and in the CT and MT treatments under maize and oats canopy. However, these indices were not substantially affected by cumulative rain in the NT treatment, whose surface was protected with previous crop residues. Roughness decay from initial values was larger in the BS treatment than in CT and MT treatments. Moreover, roughness decay generally tended to be faster under maize than under oats. The RR and LD indices decreased quadratically, while the l index decreased exponentially in the tilled, BS, CT and MT treatments. Crossover length was sensitive to differences in soil roughness conditions allowing a description of microrelief decay due to rainfall in the tilled treatments, although better correlations between

  3. The effect of land use change on water quality: A case study in Ciliwung Watershed

    Science.gov (United States)

    Ayu Permatasari, Prita; Setiawan, Yudi; Nur Khairiah, Rahmi; Effendi, Hefni

    2017-01-01

    Ciliwung is the biggest river in Jakarta. It is 119 km long with a catchment area of 476 km2. It flows from Bogor Regency and crosses Bogor City, Depok City, and Jakarta before finally flowing into Java Sea through Jakarta Bay. The water quality in Ciliwung River has degraded. Many factors affect water quality. Understanding the relationship between land use and surface water quality is necessary for effective water management. It has been widely accepted that there is a close relationship between the land use type and water quality. This study aims to analyze the influence of various land use types on the water quality within the Ciliwung Watershed based on the water quality monitoring data and remote sensing data in 2010 and 2014. Water quality parameters exhibited significant variations between the urban-dominated and forest-dominated sites. The proportion of urban land was strongly positively associated with total nitrogen and ammonia nitrogen concentrations. The result can provide scientific reference for the local land use optimization and water pollution control and guidance for the formulation of policies to coordinate the exploitation and protection of the water resource.

  4. EDGE EFFECT IN ATLANTIC FOREST REMNANTS IN THE WATERSHED OF THE RIVER TAPACURÁ, PERNAMBUCO

    Directory of Open Access Journals (Sweden)

    Lamartine Soares Cardoso de Oliveira

    2015-06-01

    Full Text Available The objective of this study was to evaluate the edge effect on arboreal component of two Atlantic Forest fragments, in the Watershed of Tapacurá River, Pernambuco. For the sampling of the adult component 15 plots of 10 x 25 m were plotted and subplots of 1 x 25 m for the regeneration. The plots were arranged in three environments, with five sampling units each, according to distance from the edge. Comparisons between the environments were performed by specie composition, Venn diagram and cluster analysis. The greatest richness was observed in the area farther from the edge and the greatest number of individuals near the edge. In the Mata da Onça, the farthest edge environments were similar, but different in composition and structure as compared to the nearest environment. However, in the Mata da Buchada the first two environments near to the edge were similar. The interaction between the human environment and the fragment affects the arboreal community in the fragment edges.

  5. Cumulative fatigue damage models

    Science.gov (United States)

    Mcgaw, Michael A.

    1988-01-01

    The problem of calculating expected component life under fatigue loading conditions is complicated by the fact that component loading histories contain, in many cases, cyclic loads of widely varying amplitudes. In such a case a cumulative damage model is required, in addition to a fatigue damage criterion, or life relationship, in order to compute the expected fatigue life. The traditional cumulative damage model used in design is the linear damage rule. This model, while being simple to use, can yield grossly unconservative results under certain loading conditions. Research at the NASA Lewis Research Center has led to the development of a nonlinear cumulative damage model, named the double damage curve approach (DDCA), that has greatly improved predictive capability. This model, which considers the life (or loading) level dependence of damage evolution, was applied successfully to two polycrystalline materials, 316 stainless steel and Haynes 188. The cumulative fatigue behavior of the PWA 1480 single-crystal material is currently being measured to determine the applicability of the DDCA for this material.

  6. Regional Response of Ecological Effects of Cascade Reservoirs Development within the Maotiaohe River Watershed%Regional Response of Ecological Effects of Cascade Reservoirs Development within the Maotiaohe River Watershed

    Institute of Scientific and Technical Information of China (English)

    李亦秋; 鲁春霞; 邓欧; 杨广斌

    2011-01-01

    Studying regional ecological effects of water conservancy projects plays a significant role in improving water resources use efficiency and reducing negative effects of the water conservancy projects. In this study, the authors took the environmental impact of water conservancy projects and the resulting regional response to ecosystems as a subject. Based on a cascade development concept model of ecological effects of regional response of the Maotiao River watershed, mutual contact and restraint ecosystems, including river ecosystems, terrestrial ecosystems, and human living and production systems, were analyzed and summarized according to the level order of regional response of ecological effects at the temporal scale and ecological spatial scale. A comprehensive analysis was performed on the regional response of non-ecological and ecological variables in the above-mentioned three ecosystems in the Maotiao River watershed. Regional ecological effects of water conservancy projects in the Maotiao River watershed were analyzed in terms of 1) regional response of non-ecological and ecological variables, such as hydrological regime and water quantity, water quality and water environment, and aquatic community of river ecosystems, 2) regional response of non-ecological and ecological variables, such as air quality, regional climate change, and other terrestrial vegetation and wildlife of terrestrial ecosystems, and 3) regional response of land resources, cultivated land area, and population health, etc. of human living and production systems. It was found that the watershed development has resulted in population growth, industry concentration, social development, as well as a series of irreversible ecological and environmental problems which made the contradiction between people and land more acute. Therefore, for a watershed in which the cascade development has been achieved, much effort should be made to shift the industrial structure from high energy

  7. Potential effects of climate change on streamflow for seven watersheds in eastern and central Montana

    Science.gov (United States)

    Chase, Katherine J.; Haj, Adel; Regan, R. Steven; Viger, Roland J.

    2016-01-01

    Study regionEastern and central Montana.Study focusFish in Northern Great Plains streams tolerate extreme conditions including heat, cold, floods, and drought; however changes in streamflow associated with long-term climate change may render some prairie streams uninhabitable for current fish species. To better understand future hydrology of these prairie streams, the Precipitation-Runoff Modeling System model and output from the RegCM3 Regional Climate model were used to simulate streamflow for seven watersheds in eastern and central Montana, for a baseline period (water years 1982–1999) and three future periods: water years 2021–2038 (2030 period), 2046–2063 (2055 period), and 2071–2088 (2080 period).New hydrological insights for the regionProjected changes in mean annual and mean monthly streamflow vary by the RegCM3 model selected, by watershed, and by future period. Mean annual streamflows for all future periods are projected to increase (11–21%) for two of the four central Montana watersheds: Middle Musselshell River and Cottonwood Creek. Mean annual streamflows for all future periods are projected to decrease (changes of −24 to −75%) for Redwater River watershed in eastern Montana. Mean annual streamflows are projected to increase slightly (2–15%) for the 2030 period and decrease (changes of −16 to −44%) for the 2080 period for the four remaining watersheds.

  8. Double dose: the cumulative effect of TV viewing at home and in preschool on children's activity patterns and weight status.

    Science.gov (United States)

    Taverno Ross, Sharon; Dowda, Marsha; Saunders, Ruth; Pate, Russell

    2013-05-01

    Little is known about how screen-based sedentary behavior at home and in preschool influences children's health and activity patterns. The current study examined the individual and cumulative influence of TV viewing at home and in preschool on children's physical activity (PA) and weight status. Children (n = 339) attending 16 preschools in South Carolina were grouped into high and low TV groups based on parent report of children's TV viewing at home and director report of TV use/rules in preschool. T-tests and mixed model ANOVAs examined differences in weight status and PA (min/hr) by high and low TV groups. Results revealed that children who were classified as High TV both at home and in pre- school had significantly lower levels of moderate-to-vigorous PA compared with their Low TV counterparts (8.3 (0.3) min/hr vs. 7.6 (0.2) min/hr, p TV groups at home or in preschool when examined individually. These findings demonstrate the importance of total environmental TV exposure on preschooler's PA. Longitudinal and observational research to assess preschoolers' cumulative screen-based sedentary behavior and its relationship with PA and weight status is needed.

  9. Comparison of the Effects of the Different Methods for Computing the Slope Length Factor at a Watershed Scale

    Directory of Open Access Journals (Sweden)

    Fu Suhua

    2013-09-01

    Full Text Available The slope length factor is one of the parameters of the Universal Soil Loss Equation (USLE and the Revised Universal Soil Loss Equation (RUSLE and is sometimes calculated based on a digital elevation model (DEM. The methods for calculating the slope length factor are important because the values obtained may depend on the methods used for calculation. The purpose of this study was to compare the difference in spatial distribution of the slope length factor between the different methods at a watershed scale. One method used the uniform slope length factor equation (USLFE where the effects of slope irregularities (such as slope gradient, etc. on soil erosion by water were not considered. The other method used segmented slope length factor equation(SSLFE which considered the effects of slope irregularities on soil erosion by water. The Arc Macro Language (AML Version 4 program for the revised universal soil loss equation(RUSLE.which uses the USLFE, was chosen to calculate the slope length factor. In a parallel analysis, the AML code of RUSLE Version 4 was modified according to the SSLFE to calculate the slope length factor. Two watersheds with different slope and gully densities were chosen. The results show that the slope length factor and soil loss using the USLFE method were lower than those using the SSLFE method, especially on downslopes watershed with more frequent steep slopes and higher gully densities. In addition, the slope length factor and soil loss calculated by the USLFE showed less spatial variation.

  10. Effects of sampling interval on spatial patterns and statistics of watershed nitrogen concentration

    Science.gov (United States)

    Wu, S.-S.D.; Usery, E.L.; Finn, M.P.; Bosch, D.D.

    2009-01-01

    This study investigates how spatial patterns and statistics of a 30 m resolution, model-simulated, watershed nitrogen concentration surface change with sampling intervals from 30 m to 600 m for every 30 m increase for the Little River Watershed (Georgia, USA). The results indicate that the mean, standard deviation, and variogram sills do not have consistent trends with increasing sampling intervals, whereas the variogram ranges remain constant. A sampling interval smaller than or equal to 90 m is necessary to build a representative variogram. The interpolation accuracy, clustering level, and total hot spot areas show decreasing trends approximating a logarithmic function. The trends correspond to the nitrogen variogram and start to level at a sampling interval of 360 m, which is therefore regarded as a critical spatial scale of the Little River Watershed. Copyright ?? 2009 by Bellwether Publishing, Ltd. All right reserved.

  11. Hydrological Effects of Chashm Dam on the Downstream of Talar River Watershed

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Khaleghi

    2017-02-01

    Full Text Available Introduction: In the last century, dams have constructed with the objective of water supplies for agriculture, drinking water and industry. However, the results from the performance review of dams show adverse effects on the downstream environment and the availability of water resources. The purpose of the Chashm dam construction on the TalarRiver's tributaries is the water supply for Semnan city. Materials and Methods: This study was conducted in TalarRiver watershed. TalarRiveroriginatesfrom AlborzMountains in Mazandaran province, in the southern Caspian Sea basin, in north of Iran and flows parallel with the Firouzkooh-Ghaemshahr road and it arrives to the Caspian beach area in the Malek Kala village. In order to supply the water requirements of Semnan city, the construction of Chashm dam on the TalarRiver's tributaries placed on the agenda of the Ministry of Energy. However, because of the uncontrolled exploitation of agricultural streams and invasion of privacy riverbed, the TalarRiver has acute and critical conditions from the point of hydrologic and environmental. To study the hydrological impacts of Chashm dam, Talar watershed was considered with an area of approximately 1057 square kilometers of the Pole Sefid gauging station using a rainfall-runoff model. Results and Discussion: Simulation of the study area hydrological behavior shows that the Chashm Dam average water discharge is near to 8.6 million m3. This figure will be significant changes during wet and droughtperiods. The minimum and maximum monthly discharge of the Chashm Dam watershed in August and February is equal to 0.31 and 0.55 m3/s respectively. The minimum and maximum monthly water demand in turn in October and August is equal to 0.015 and 0.4 m3/s respectively and this shows that the river discharge in June is lower than the downstream water demand. Based on confirmed studies of the Kamandab Consulting Engineers, drinking water requirement of Semnan province, water

  12. To what effect? A comparison of cumulative wildlife effects from wind and other major electricity generation types

    Energy Technology Data Exchange (ETDEWEB)

    Newman, C.; Denny, C.; Colverson, P.; Marynowski, S.; Hill, K. [Pandion Systems Inc., Gainesville, FL (United States); Newman, J. [Pandion Systems Inc., Gainsville, FL (United States)]|[Environmental Bioindicators Foundation EBIF Inc., Fort Pierce, FL (United States); Zillioux, E. [Environmental Bioindicators Foundation EBIF Inc., Fort Pierce, FL (United States); Warren-Hicks, W. [Eco-Stat Inc., Highland City, FL (United States); Watson, M. [New York State Energy Research and Development Authority, Albany, NY (United States)

    2008-07-01

    The New York State Energy Research and Development Authority (NYSERDA) report was designed to compare the relative risks of different methods of energy generation. Risks were assessed from resource extraction through to decommissioning in order to assess relative risk at all life-cycles. Generation sources included coal; oil; natural gas; nuclear; hydro; and wind power. The ecological risk assessment framework was designed to consider stressors and receptors as well as to characterize risks to wildlife from electricity generation. Exposure and effects ranged from large-scale injury or mortality to low risks with no population effects. The study showed that risks from energy generation include climatic change, acid deposition, mercury, and bioaccumulation. Impacts also include physical injury and mortality to wildlife, disruption of normal behaviour, and destruction of habitat. It was concluded that the resource extraction and fuel transportation phases of both hydro and wind power pose no risk to wildlife. Power generation, transmission, and delivery of wind energy pose a medium risk to wildlife. It was concluded that coal-derived energy poses the highest risk to wildlife out of all the examined energy sources. tabs., figs.

  13. Effects of Land-Use Change on Characteristics and Dynamics of Watershed Discharges in Babeldaob, Palau, Micronesia

    Directory of Open Access Journals (Sweden)

    Yimnang Golbuu

    2011-01-01

    Full Text Available This study assessed the impacts of differing levels of land development in four watersheds in Palau on river sediment yield and on sedimentation and turbidity. Area corrected sediment yield was strongly related to land development (r2=0.96, P=0.02, varying from 9.7 to 216 tons km−2 yr−1 between the least and most developed watershed. Mean sedimentation rates on reefs ranged from 0.7 to 46 mg cm−2 d−1, and mean turbidity ranged from 9 to 139 mg l−1. The higher values exceeded those known to harm corals. Because Palau's watersheds and estuaries are small, river floods were short-lived (typically lasting less than a day and the estuaries adjusted just as quickly to a number of different estuarine circulation patterns that, in turn, generated a large variability in the export of riverine fine sediment to the reefs. The ultimate fate of the fine sediment deposited on the reefs depended on wind resuspension, local currents, and geomorphology (whether the bay was open or semi-enclosed. Palau's small estuaries were generally not as effective as bigger estuaries in trapping sediments and thus at sheltering the reefs. Therefore, greater efforts are needed to control and mitigate land activities that contribute to the increase in sediment yield.

  14. Simulation of streamflow and the effects of brush management on water yields in the upper Guadalupe River watershed, south-central Texas, 1995-2010

    Science.gov (United States)

    Bumgarner, Johnathan R.; Thompson, Florence E.

    2012-01-01

    The U.S. Geological Survey, in cooperation with the Texas State Soil and Water Conservation Board and the Upper Guadalupe River Authority, developed and calibrated a Soil and Water Assessment Tool watershed model of the upper Guadalupe River watershed in south-central Texas to simulate streamflow and the effects of brush management on water yields in the watershed and to Canyon Lake for 1995–2010. Model simulations were done to quantify the possible change in water yield of individual subbasins in the upper Guadalupe River watershed as a result of the replacement of ashe juniper (Juniperus ashei) with grasslands. The simulation results will serve as a tool for resource managers to guide their brush-management efforts.

  15. Simulation of streamflow and the effects of brush management on water yields in the Double Mountain Fork Brazos River watershed, western Texas 1994–2013

    Science.gov (United States)

    Harwell, Glenn R.; Stengel, Victoria G.; Bumgarner, Johnathan R.

    2016-04-20

    The U.S. Geological Survey, in cooperation with the City of Lubbock and the Texas State Soil and Water Conservation Board, developed and calibrated a Soil and Water Assessment Tool watershed model of the Double Mountain Fork Brazos River watershed in western Texas to simulate monthly mean streamflow and to evaluate the effects of brush management on water yields in the watershed, particularly to Lake Alan Henry, for calendar years 1994–2013. Model simulations were done to quantify the possible change in water yield of individual subbasins in the Double Mountain Fork Brazos River watershed as a result of the replacement of shrubland (brush) with grassland. The simulation results will serve as a tool for resource managers to guide brush-management efforts.

  16. Effects of Fire on Soil Properties, Erosion and Hydrologic Regime of Zrebar Lake Watershed

    Directory of Open Access Journals (Sweden)

    Shirko Ebrahimi Mohammadi

    2017-02-01

    Full Text Available Introduction: Forest herbs due to decrease of runoff coefficient and the kinetic energy of raindrops, is known as a key factor in controlling runoff and soil conservation. Many physical (hydrophobicity, electrical conductivity, pH, particle size distribution, color and temperature regimes, chemical (quality and quantity of organic matter, nutrient availability and biological (Microbial biomass, soil invertebrates living community soil properties can be affected by forest fires. Fire not only reduces forest herbs, vulnerability against splashing rain but also has strong effects on the hydrological cycle and soil loss. despite of repeated fires, there are very few studies about fire impact on natural resources of the west of the country, especially the city of Marivan, in Kurdistan province so this study aimed to investigate the short-term fire impacts on soil properties, Hydrologic regime, soil erosion and sedimentation of Zrebar Lake watershed in west of Iran. Materials and Methods: Considering the importance of the slope on the hydrological response of the watershed, slope classes of the Zrebar Lake watershed were mapped. Therefore, effects of fire on hydrological characteristics, erosion and sedimentation were studied by the establishment of twelve 0.25 square meter plots in three replications at two dominant slope classes (0 to 30 and 30 to 60% in burned and natural areas . The first plots in the burned and natural sections, was established randomly and two other plots with the similar conditions at a distance of 1.5 meters from each other were established. Garden Spray Simulator with constant pressure was used to fall rain from half a meter height for thirty minutes with an intensity of about 2 mm min-1 and 1 mm droplet diameter according to the general weather conditions of the studied area. For every five minutes, runoff and sediment were collected. Runoff volume by weighting and suspended sediment concentration by drying at 105°c were

  17. Experimental forest watershed studies contribution to the effect of disturbances on water quality

    Science.gov (United States)

    Daniel G. Neary

    2012-01-01

    The most sustainable and best quality fresh water sources in the world originate in forested watersheds (Dissmeyer 2000, Brooks et al. 2003, Barten and Ernst 2004). The biological, chemical, and physical characteristics of forest soils are particularly well suited to delivering high quality water to streams, and moderating the climatic extremes which affect stream...

  18. Effect of Landscape-Watershed Attributes on CDOM in Florida's Gulf Coast Rivers

    Science.gov (United States)

    Conmy, R. N.; Lehrter, J. C.; Jackson, J.; Coble, P. G.; Hastings, R. H.

    2010-12-01

    Florida’s Gulf Coast has multiple river systems with unique landscape and watershed attributes. Systems that supply water and material to the West Florida Shelf include the Apalachicola, Suwannee, Tampa Bay, Charlotte Harbor and the Shark Rivers. Northern riversheds have large watershed size and are dominated by forest and agricultural land cover, whereas riversheds in Central Florida are primarily urbanized landscapes (Tampa Bay system) that transition to agricultural landscapes (Charlotte Harbor) to the south. The southernmost rivershed in the Everglades is tidally driven and has landcover dominated by water and wetlands. Despite uniqueness amongst systems, Landscape Development Intensity (LDI) scores and precipitation patterns; magnitude of river discharge can be used to explain quantity of CDOM and DOC within headwaters with data collected during 2003-2005, as well as with historic data in Tampa Bay collected through the Environmental Protection Commission of Hillsborough County (EPCHC) monitoring program. Beyond organic matter concentration within the rivers, the quality of the material, as per absorption and fluorescence properties, are correlated with the characteristics of the watershed itself, including land-use/land cover. Implications of utilizing discharge and landscape-watershed attributes in estimating flux and quality of terrestrial DOM exported to estuaries and the coastal ocean will be addressed.

  19. Identifying Cost-Effective Water Resources Management Strategies: Watershed Management Optimization Support Tool (WMOST)

    Science.gov (United States)

    The Watershed Management Optimization Support Tool (WMOST) is a public-domain software application designed to aid decision makers with integrated water resources management. The tool allows water resource managers and planners to screen a wide-range of management practices for c...

  20. "Buddha's Light" of Cumulative Particles

    CERN Document Server

    Kopeliovich, Vladimir B; Potashnikova, Irina K

    2014-01-01

    We show analytically that in the cumulative particles production off nuclei multiple interactions lead to a glory-like backward focusing effect. Employing the small phase space method we arrived at a characteristic angular dependence of the production cross section $d\\sigma \\sim 1/ \\sqrt {\\pi - \\theta}$ near the strictly backward direction. This effect takes place for any number $n\\geq 3 $ of interactions of rescattered particle, either elastic or inelastic (with resonance excitations in intermediate states), when the final particle is produced near corresponding kinematical boundary. Such a behaviour of the cross section near the backward direction is in qualitative agreement with some of available data.

  1. Study on effects of storm-water detention facilities in an urbanized watershed using a distributed model

    OpenAIRE

    賈, 仰文; 倪, 广恒; 木内, 豪; 吉谷, 純一; 河原, 能久; 末次, 忠司

    2001-01-01

    A distributed hydrological model - WEP (Water and Energy transfer Process) model is improved at first by adding overland flow and storm-water detention pond's components, as well as changing the kinematic wave method into the dynamic wave method for the flow routing of main rivers to consider tidal effects. The modified model is then utilized to evaluate the effects of storm-water detention ponds and infiltration trenches in the Ebi river watershed with a grid size of 50m and a time step of 1...

  2. Evaluating the Effectiveness of Agricultural Management Practices under Climate Change for Water Quality Improvement in a Rural Agricultural Watershed of Oklahoma, USA

    Science.gov (United States)

    Rasoulzadeh Gharibdousti, S.; Kharel, G.; Stoecker, A.; Storm, D.

    2016-12-01

    One of the main causes of water quality impairment in the United States is human induced Non-Point Source (NPS) pollution through intensive agriculture. Fort Cobb Reservoir (FCR) watershed located in west-central Oklahoma, United States is a rural agricultural catchment with known issues of NPS pollution including suspended solids, siltation, nutrients, and pesticides. The FCR watershed with an area of 813 km2 includes one major lake fed by four tributaries. Recently, several Best Management Practices (BMPs) have been implemented in the watershed (such as no-tillage and cropland to grassland conversion) to improve water quality. In this study we aim to estimate the effectiveness of different BMPs in improving watershed health under future climate projections. We employed the Soil and Water Assessment Tool (SWAT) to develop the hydrological model of the FCR watershed. The watershed was delineated using the 10 m USGS Digital Elevation Model and divided into 43 sub-basins with an average area of 8 km2 (min. 0.2 km2 - max. 28 km2). Through a combination of Soil Survey Geographic Database- SSURGO soil data, the US Department of Agriculture crop layer and the slope information, the watershed was further divided into 1,217 hydrologic response units. The historical climate pattern in the watershed was represented by two different weather stations. The model was calibrated (1991 - 2000) and validated (2001 - 2010) against the monthly USGS observations of streamflow recorded at the watershed outlet using three statistical matrices: coefficient of determination (R2), Nash-Sutcliffe efficiency (NS) and percentage bias (PB). Model parametrization resulted into satisfactory values of R2 (0.56) and NS (0.56) in calibration period and an excellent model performance (R2 = 0.75; NS = 0.75; PB = <1) in validation period. We have selected 19 BMPs to estimate their efficacy in terms of water and sediment yields under a combination of three Coupled Model Intercomparison Project-5 Global

  3. The effects of increased constant incubation temperature and cumulative acute heat shock exposures on morphology and survival of Lake Whitefish (Coregonus clupeaformis) embryos.

    Science.gov (United States)

    Lee, Abigail H; Eme, John; Mueller, Casey A; Manzon, Richard G; Somers, Christopher M; Boreham, Douglas R; Wilson, Joanna Y

    2016-04-01

    Increasing incubation temperatures, caused by global climate change or thermal effluent from industrial processes, may influence embryonic development of fish. This study investigates the cumulative effects of increased incubation temperature and repeated heat shocks on developing Lake Whitefish (Coregonus clupeaformis) embryos. We studied the effects of three constant incubation temperatures (2°C, 5°C or 8°C water) and weekly, 1-h heat shocks (+3°C) on hatching time, survival and morphology of embryos, as these endpoints may be particularly susceptible to temperature changes. The constant temperatures represent the predicted magnitude of elevated water temperatures from climate change and industrial thermal plumes. Time to the pre-hatch stage decreased as constant incubation temperature increased (148d at 2°C, 92d at 5°C, 50d at 8°C), but weekly heat shocks did not affect time to hatch. Mean survival rates and embryo morphometrics were compared at specific developmental time-points (blastopore, eyed, fin flutter and pre-hatch) across all treatments. Constant incubation temperatures or +3°C heat-shock exposures did not significantly alter cumulative survival percentage (~50% cumulative survival to pre-hatch stage). Constant warm incubation temperatures did result in differences in morphology in pre-hatch stage embryos. 8°C and 5°C embryos were significantly smaller and had larger yolks than 2°C embryos, but heat-shocked embryos did not differ from their respective constant temperature treatment groups. Elevated incubation temperatures may adversely alter Lake Whitefish embryo size at hatch, but weekly 1-h heat shocks did not affect size or survival at hatch. These results suggest that intermittent bouts of warm water effluent (e.g., variable industrial emissions) are less likely to negatively affect Lake Whitefish embryonic development than warmer constant incubation temperatures that may occur due to climate change.

  4. Forest Conversion to Land of Rubber and Palm Oil Farming and Its Effect on Run Off and Soil Erosion in Batang Pelepat Watershed

    Directory of Open Access Journals (Sweden)

    Sunarti

    2008-09-01

    Full Text Available Forest conversion to some land use happened in all watershed, includes Batang Pelepat watershed. The objectives of this research are to know effect of forest conversion to land of rubber (Hevea brasiliensis and palm oil (Elaeis guinensis Jack farming on run off and soil erosion and different of erosion rate on agro technology of rubber and palm oil farming in Batang Pelepat watershed. The research was carried out during 3 months, begin October to December 2006. Run off and soil erosion measured plot with gutter in the lower of plot. Experimental design for this research is randomized complete block design, with land use type as treatment and slope class as replication or block. Data analyzed statistically by variance analysis (F-test and Duncan New Multiple Range Test on confidence 95% (á = 0.05. The results of this research show that area of forest coverage in Batang Pelepat watershed was decreasing. In 1986 this area still 94.50% of watershed area, but in 1994 area of forest only 78.17% and in 2006 forest area 64.20% of watershed area. Forest conversion was carried out to land of rubber and palm oil farming with some actual agro technologies. Land of monoculture rubber I resulted the highest run off and soil erosion more than the other land use type and showed different of run off and soil erosion on land of secondary forest.

  5. Climate and Land Use Change Effects on Ecological Resources in Three Watersheds: A Synthesis Report (Final Report)

    Science.gov (United States)

    The purpose of this final report is to provide a summary of climate change impacts to selected watersheds and recommendations for how to improve the process of conducting watershed assessments in the future.

  6. Watershed Scale Impacts of Stormwater Green Infrastructure on Hydrology and Nutrient Fluxes in the Mid-Atlantic Region.

    Science.gov (United States)

    Jaffe, P. R.; Pennino, M. J.; McDonald, R.

    2015-12-01

    Stormwater green infrastructure (SGI), including rain gardens, detention ponds, bioswales, and green roofs, is being implemented in cities across the globe to help reduce flooding, decrease combined sewer overflows, and lessen pollutant transport to streams and rivers. Despite the increasing use of urban SGI, there is much uncertainty regarding the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the cumulative effects of SGI, major cities across the mid-Atlantic were selected based on availability of SGI, water quality, and stream flow data. The impact of SGI was evaluated by comparing similar watersheds, with and without SGI or by assessing how long-term changes in SGI impact hydrologic and water quality metrics over time. Most mid-Atlantic cities have a goal of achieving 10-75% SGI by 2030. Of these cites, Washington D.C. currently has the highest density of SGI (15.5%), while Philadelphia, PA and New York, NY have the lowest (0.14% and 0.28%, respectively). When comparing watersheds of similar size and percent impervious surface cover, watersheds with lower amounts of SGI, on average, show up to 40% greater annual total nitrogen and 75% greater total phosphorus loads and show flashier hydrology (as indicated by 35% greater average peak discharge, 26% more peak discharge events per year, and 21% higher peak-to-volume ratio) compared to watersheds with higher amounts of SGI. However, for cities with combined sewer systems (e.g. Washington, D.C. and Philadelphia, PA), there was no relationship between the level of combined sewer overflows (CSOs) and the amount of SGI, indicating the level of SGI may not yet be sufficient to reduce CSOs as intended. When comparing individual watersheds over time, increases in SGI show no significant effect on the long-term trends in nutrient loads or hydrologic variables, potentially being obscured by the larger effect of interannual variability.

  7. Examination of cumulative effects of early adolescent depression on cannabis and alcohol use disorder in late adolescence in a community-based cohort.

    Science.gov (United States)

    Rhew, Isaac C; Fleming, Charles B; Vander Stoep, Ann; Nicodimos, Semret; Zheng, Cheng; McCauley, Elizabeth

    2017-06-10

    Although they often co-occur, the longitudinal relationship between depression and substance use disorders during adolescence remains unclear. This study estimated the effects of cumulative depression during early adolescence (ages 13-15 years) on the likelihood of cannabis use disorder (CUD) and alcohol use disorder (AUD) at age 18. Prospective cohort study of youth assessed at least annually between 6th and 9th grades (~ age 12-15) and again at age 18. Marginal structural models based on a counterfactual framework that accounted for both potential fixed and time-varying confounders were used to estimate cumulative effects of depressive symptoms over early adolescence. The sample originated from four public middle schools in Seattle, Washington, USA. The sample consisted of 521 youth (48.4% female; 44.5% were non-Hispanic White). Structured in-person interviews with youth and their parents were conducted to assess diagnostic symptom counts of depression during early adolescence; diagnoses of CUD and AUD at age 18 was based the Voice-Diagnostic Interview Schedule for Children. Cumulative depression was defined as the sum of depression symptom counts from grades 7-9. The past-year prevalence of cannabis and alcohol use disorder at the age 18 study wave was 20.9 and 19.8%, respectively. A 1 standard deviation increase in cumulative depression during early adolescence was associated with a 50% higher likelihood of CUD [prevalence ratio (PR) = 1.50; 95% confidence interval (CI) = 1.07, 2.10]. Although similar in direction, there was no statistically significant association between depression and AUD (PR = 1.41; 95% CI = 0.94, 2.11). Further, there were no differences in associations according to gender. Youth with more chronic or severe forms of depression during early adolescence may be at elevated risk for developing cannabis use disorder compared with otherwise similar youth who experience fewer depressive symptoms during early adolescence. © 2017 Society

  8. Cumulative Timers for Microprocessors

    Science.gov (United States)

    Battle, John O.

    2007-01-01

    It has been proposed to equip future microprocessors with electronic cumulative timers, for essentially the same reasons for which land vehicles are equipped with odometers (total-distance-traveled meters) and aircraft are equipped with Hobbs meters (total-engine-operating time meters). Heretofore, there has been no way to determine the amount of use to which a microprocessor (or a product containing a microprocessor) has been subjected. The proposed timers would count all microprocessor clock cycles and could only be read by means of microprocessor instructions but, like odometers and Hobbs meters, could never be reset to zero without physically damaging the chip.

  9. Cumulative Vehicle Routing Problems

    OpenAIRE

    Kara, &#;mdat; Kara, Bahar Yeti&#;; Yeti&#;, M. Kadri

    2008-01-01

    This paper proposes a new objective function and corresponding formulations for the vehicle routing problem. The new cost function defined as the product of the distance of the arc and the flow on that arc. We call a vehicle routing problem with this new objective function as the Cumulative Vehicle Routing Problem (CumVRP). Integer programming formulations with O(n2) binary variables and O(n2) constraints are developed for both collection and delivery cases. We show that the CumVRP is a gener...

  10. Prioritizing Restoration in the Hangman Creek Watershed: Predicting Baseflow through Sub-basin Modeling

    Science.gov (United States)

    Navickis-Brasch, A. S.; Fiedler, F. R.

    2013-12-01

    Land use changes since European settlement have significantly impaired the beneficial uses of Coeur d'Alene (CDA) Tribe water bodies in the Hangman Creek watershed. The cumulative impacts have resulted in a 303 (d) designation by the Environmental Protection Agency (EPA), extirpated the only salmon run on the reservation, and reduced tributary connectivity by isolating many native fish populations. Considering salmon were an essential part of tribal identity and cultural activities, the tribe initiated a 100-year management plan to restore the 155,000-acre portion of the Hangman Creek watershed located on the CDA reservation. The restoration management plan focuses on sustaining subsistence and cultural activities by reestablishing stream connectivity and providing sustainable aquatic habitats as well as restoring watershed processes and improving water quality. Ultimately, the restoration goal is to improve the habitat suitability of Hangman Creek for the eventual return of salmon. To accomplish these goals, it is essential to prioritize and sequence activities that most effectively support restoration. While watershed modeling provides a commonly accepted holistic approach to simulating watershed responses, it appears the effectiveness of models in predicting restoration success, particularly with respect to the effects of restoration on baseflow, have not been well documented. In addition, creating a representative watershed model capable of accounting for a watershed scale spatial and temporal variability generally requires extensive field measurements. This presents a challenge for developing a model of Hangman Creek, since the watershed is mostly ungauged with only limited data available at a few monitoring sites. Our approach to developing a restoration prioritization plan is to first model a subbasin in the watershed with similar characteristics and restoration goals, then utilize the subbasin model to project future baseflow responses in the larger

  11. Measurements of the effective cumulative fission yields of 143Nd, 145Nd, 146Nd, 148Nd and 150Nd for 235U in the PHENIX fast reactor

    Directory of Open Access Journals (Sweden)

    Privas Edwin

    2016-01-01

    Full Text Available The effective Neodymium cumulative fission yields for 235U have been measured in the fast reactor PHENIX relatively to the 235U fission cross-section. The data were derived from isotope-ratio measurements obtained in the frame of the PROFIL-1, PROFIL-2A and PROFIL-2B programs. The interpretations of the experimental programs were performed with the ERANOS code in association with the Joint Evaluated Fission and Fusion library JEFF-3.1.1. Final results for 143Nd, 145Nd, 146Nd, 148Nd and 150Nd were 5.61%, 3.70%, 2.83%, 1.64% and 0.66%, respectively. The relative uncertainties attached to each of the cumulative fission yields lie between 2.1% and 2.4%. The main source of uncertainty is due to the fluence scaling procedure (<2%. The uncertainties on the Neodymium capture cross-sections provide a contribution lower than 1%. The energy dependence of the fission yields was studied with the GEF code from the thermal energy to 20 MeV. Neutron spectrum average corrections, deduced from GEF calculations, were applied to our effective fission yields with the aim of estimating fission yields at 400 keV and 500 keV, as given in the International Evaluated Nuclear Data Files (JEFF, ENDF/B and JENDL. The neutron spectrum average correction calculated for the PROFIL results remains lower than 1.5%.

  12. The direct and indirect effects of watershed land use and soil type on stream water metal concentrations

    Science.gov (United States)

    Taka, M.; Aalto, J.; Virkanen, J.; Luoto, M.

    2016-10-01

    Identifying the factors controlling stream water pollutants is challenged by the diversity of potential sources, pathways, and processes. This study tests the effects of watershed characteristics on stream water metal concentrations across environmental gradients. By using an extensive data set of 83 watersheds in southern Finland and structural equation modeling (SEM), the direct and indirect effects of land use and soil type on metal concentrations were explored. Both land use and soil type resulted in statistically significant direct effects on metals; for example, land use was found to control dissolved metal concentrations, whereas soil type had the strongest links for total metal concentrations. The consideration of indirect correlation further strengthened the effects of soil type up to 50%, thus suggesting the dominant role of soil across land use intensities. Moreover, the results indicate that modified landscapes mediate the effect of natural soil processes in controlling stream metal concentrations. This work highlights the benefits of structural equation model framework, as the underlying paths for water quality are more likely to be identified, compared to traditional regression methods. Thus, the implementation of SEM on water quality studies is highly encouraged.

  13. Watersheds in disordered media

    Directory of Open Access Journals (Sweden)

    José S. Andrade Jr.

    2015-02-01

    Full Text Available What is the best way to divide a rugged landscape? Since ancient times, watershedsseparating adjacent water systems that flow, for example, toward different seas, have beenused to delimit boundaries. Interestingly, serious and even tense border disputes betweencountries have relied on the subtle geometrical properties of these tortuous lines. For instance,slight and even anthropogenic modifications of landscapes can produce large changes in awatershed, and the effects can be highly nonlocal. Although the watershed concept arisesnaturally in geomorphology, where it plays a fundamental role in water management, landslide,and flood prevention, it also has important applications in seemingly unrelated fields suchas image processing and medicine. Despite the far-reaching consequences of the scalingproperties on watershed-related hydrological and political issues, it was only recently that a moreprofound and revealing connection has been disclosed between the concept of watershed andstatistical physics of disordered systems. This review initially surveys the origin and definition of awatershed line in a geomorphological framework to subsequently introduce its basic geometricaland physical properties. Results on statistical properties of watersheds obtained from artificialmodel landscapes generated with long-range correlations are presented and shown to be ingood qualitative and quantitative agreement with real landscapes.

  14. Effect of Drainage Ditch Layout on Nitrogen Loss by Runoff from an Agricultural Watershed

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhan-Yu; KONG Li-Li; ZHU Lei; R.M.MWIYA

    2013-01-01

    A comparison experiment was performed,by designing one field ditch (D1 treatment),two field ditches (D2 treatment),three field ditches (D3 treatment),and no field ditch (CK treatment),in an upland of a small agricultural watershed in Nanjing-Zhenjiang hilly regions to observe the farmland surface runoff and N loss characteristics under the different layouts of field ditch.As the layout density of field ditch increased,the drainage effect was improved,the timing of the runoff peak was advanced,and also the peak flow was augmented.At the same time,both the concentration and accumulated transfer flux of total nitrogen (TN) were improved,and thereinto the accumulated transfer fluxes of TN under D3,D2 and D1 treatments were increased by 1.46,1.34 and 1.16 times,respectively,than that under CK treatment.However,the accumulated transfer fluxes of nitrate-nitrogen (NO3--N) and ammonium-nitrogen (NH4+-N) under D3,D2 and D1 treatments were reduced by 33.9%,21.4% and 8.6%,and 35.8%,24.7% and 12.2%,respectively,compared with those under CK treatment.Under CK treatment,the NO3--N and NH4+-N concentrations were more sensitive to rainfall intensity than the TN concentration.There were significant linear relationships between the transfer fluxes of TN,NO3--N and NH4+-N and the runoff flux,with the correlation coefficients of 0.942,0.899 and 0.912,respectively.In addition,this correlation was also influenced by the layout density of field ditch.Therefore,the environmental effect should be taken into account when designing and constructing field ditches.Especially in the regions of severe fertilizer loss,the approaches of properly increasing the drainage area and decreasing the layout density of field ditch could be adopted under the precondition of avoiding crops from waterlogging.

  15. Modeling the effects of climate change on water, sediment, and nutrient yields from the Maumee River watershed

    Directory of Open Access Journals (Sweden)

    Luke K. Cousino

    2015-09-01

    New hydrological insights for the region: Moderate climate change scenarios reduced annual flow (up to −24% and sediment (up to −26% yields, while a more extreme scenario showed smaller flow reductions (up to −10% and an increase in sediment (up to +11%. No-till practices had a negligible effect on flow but produced 16% lower average sediment loads than scenarios using current watershed conditions. At high implementation rates, no-till practices could offset any future increases in annual sediment loads, but they may have varied seasonal success. Regardless of future climate change intensity, increased remediation efforts will likely be necessary to significantly reduce HABs in Lake Erie's WB.

  16. Biofuel Induced Land Use Change effects on Watershed Hydrology and Water Quality

    Science.gov (United States)

    Chaubey, I.; Cibin, R.; Frankenberger, J.; Cherkauer, K. A.; Volenec, J. J.; Brouder, S. M.

    2015-12-01

    High yielding perennial grasses such as Miscanthus and switchgrass, and crop residues such as corn stover are expected to play a significant role in meeting US biofuel production targets. We have evaluated the potential impacts of biofuel induced land use changes on hydrology, water quality, and ecosystem services. The bioenergy production scenarios, included: production of Miscanthus × giganteus and switchgrass on highly erodible landscape positions, agricultural marginal land areas, and pastures; removal of corn stover at various rates; and combinations of these scenarios. The hydrology and water quality impacts of land use change scenarios were estimated for two watersheds in Midwest USA (1) Wildcat Creek watershed (drainage area of 2,083 km2) located in north-central Indiana and (2) St. Joseph River watershed (drainage area of 2,809 km2) located in Indiana, Ohio, and Michigan. We have also simulated the impacts of climate change and variability on environmental sustainability and have compared climate change impacts with land use change impacts. The study results indicated improved water quality with perennial grass scenarios compared to current row crop production impacts. Erosion reduction with perennial energy crop production scenarios ranged between 0.2% and 59%. Stream flow at the watershed outlet were reduced between 0.2 and 8% among various bioenergy crop production scenarios. Stover removal scenarios indicated increased erosion compared to baseline condition due reduced soil cover after stover harvest. Stream flow and nitrate loading were reduced with stover removal due to increased soil evaporation and reduced mineralization. A comparison of land use and climate change impacts indicates that land use changes will have considerably larger impacts on hydrology, water quality and environmental sustainability compared to climate change and variability. Our results indicate that production of biofuel crops can be optimized at the landscape level to provide

  17. Effects of watershed land use on nitrogen concentrations and δ15 nitrogen in groundwater

    Science.gov (United States)

    Cole, Marci L.; Kroeger, Kevin D.; McClelland, J.W.; Valiela, I.

    2006-01-01

    Eutrophication is a major agent of change affecting freshwater, estuarine, and marine systems. It is largely driven by transportation of nitrogen from natural and anthropogenic sources. Research is needed to quantify this nitrogen delivery and to link the delivery to specific land-derived sources. In this study we measured nitrogen concentrations and δ 15N values in seepage water entering three freshwater ponds and six estuaries on Cape Cod, Massachusetts and assessed how they varied with different types of land use. Nitrate concentrations and δ 15N values in groundwater reflected land use in developed and pristine watersheds. In particular, watersheds with larger populations delivered larger nitrate loads with higher δ 15N values to receiving waters. The enriched δ 15N values confirmed nitrogen loading model results identifying wastewater contributions from septic tanks as the major N source. Furthermore, it was apparent that N coastal sources had a relatively larger impact on the N loads and isotopic signatures than did inland N sources further upstream in the watersheds. This finding suggests that management priorities could focus on coastal sources as a first course of action. This would require management constraints on a much smaller population.

  18. Mitigating the effects of landscape development on streams in urbanizing watersheds

    Science.gov (United States)

    Hogan, Dianna M.; Jarnagin, S. Taylor; Loperfido, John V.; Van Ness, Keith

    2013-01-01

    This collaborative study examined urbanization and impacts on area streams while using the best available sediment and erosion control (S&EC) practices in developing watersheds in Maryland, United States. During conversion of the agricultural and forested watersheds to urban land use, land surface topography was graded and vegetation was removed creating a high potential for sediment generation and release during storm events. The currently best available S&EC facilities were used during the development process to mitigate storm runoff water quality, quantity, and timing before entering area streams. Detailed Geographic Information System (GIS) maps were created to visualize changing land use and S&EC practices, five temporal collections of LiDAR (light detection and ranging) imagery were used to map the changing landscape topography, and streamflow, physical geomorphology, and habitat data were used to assess the ability of the S&EC facilities to protect receiving streams during development. Despite the use of the best available S&EC facilities, receiving streams experienced altered flow, geomorphology, and decreased biotic community health. These impacts on small streams during watershed development affect sediment and nutrient loads to larger downstream aquatic ecosystems such as the Chesapeake Bay.

  19. Assessing the short- and long-term effects of land development on watershed erosion and sediment delivery to marine ecosystems of the U.S. Virgin Islands

    Science.gov (United States)

    Ramos-Scharron, C. E.; Gray, S. C.; Sears, W.; Brooks, G.; Larson, R. A.

    2014-12-01

    Throughout history, significant portions of the native vegetation of many Caribbean islands were replaced by cropland. Even though most islands eventually underwent reforestation, sediment yields and deposition rates appear to be higher now than throughout the past millennia, and this suggests that coral reef systems are experiencing an unprecedented level of sediment-related stress. Given the present-day emphasis on erosion control projects to restore coral reefs of the US Caribbean, it is of utmost importance to develop a quantitative understanding of the effects of both land development and watershed restoration activities on sediment delivery at various spatio-temporal scales. Efforts to measure contemporary erosion, sediment delivery and deposition rates have been conducted on the island of St. John-USVI since 2009. Sediment yields under natural conditions from the small (<10 km2) watersheds in this dry sub-tropical setting are between 1 and 10 Mg km-2 yr-1. Current sediment yields are 2 - 50 times higher than background depending on unpaved road network abundance and characteristics. Our efforts indicate that a watershed restoration program implemented in 2010-2011 within the 13-km2 Coral Bay watershed resulted in the reduction of annual sediment delivery rates from 445 Mg yr-1 to 327 Mg yr-1. Marine sedimentation rates of terrigenous materials based on sediment trap data were 6 - 24 times greater below developed watersheds relative to undeveloped catchments and were consistent with spatial comparisons of modeled sediment yields. At sites located within reef systems, total and silt deposition rates during sampling periods with major storms exceeded rates shown to harm corals more frequently in developed areas. Terrigenous sedimentation rates during periods with equivalent storms were reduced following watershed restoration. These results suggest that targeted watershed restoration may be effective in reducing sedimentation where land development and sediments

  20. Effects of inundation frequency on microbial N cycling in the riparian zones of pristine watersheds

    Science.gov (United States)

    Malone, E. T.; Bartlett, R.; Pinay, G.; Milner, A. M.

    2012-12-01

    Although the N cycle has been intensively studied new reaction pathways are being discovered. Perturbation by anthropogenic N inputs changes the type of loading and cycling processes in soil systems. Few pristine environments remain in which to study natural controls on the development of N cycling to increase our understanding of the natural development of such mechanisms and with which to compare the effects of anthropogenic inputs. This study took place in Glacier Bay National Park and Preserve, in southeast Alaska (GBNP).Where rapid de-glaciation over the last 250 years has created watersheds of different ages free from anthropogenic N inputs, permitting a unique opportunity to study the evolution of microbial N cycling in pristine soil systems. Soil N cycling was assessed within six study streams selected across a chronosequence of 200 years of primary succession. A combination of field and laboratory methods were used to assess the soil inorganic N status of each study site and assess the net, gross and potential microbial processing of N (ammonification, nitrification and denitrification) present within the soil. Soil samples were collected from the riparian zones of the six river catchments with varying inundation frequencies; namely 1) frequently inundated bare sediment adjacent to the river channel; 2) vegetated floodplain areas further from the channel inundated during high flow events; 3) non flooded. This approach allowed a cross stream comparison of microbial N processing for a range of soil ages, and under differing inundation regimes. Evolution of soil N processing could then be examined, in relation to successional changes in the wider river catchment. One of the key findings was that one of the primary influences on nitrogen cycling processes in the study areas was vegetation cover, as a function of site resilience and distance from stream channel. With distance from a stream channel, a site becomes less dynamic, thereby allowing for the

  1. Exploring the Non-Stationary Effects of Forests and Developed Land within Watersheds on Biological Indicators of Streams Using Geographically-Weighted Regression

    Directory of Open Access Journals (Sweden)

    Kyoung-Jin An

    2016-03-01

    Full Text Available This study examined the non-stationary relationship between the ecological condition of streams and the proportions of forest and developed land in watersheds using geographically-weighted regression (GWR. Most previous studies have adopted the ordinary least squares (OLS method, which assumes stationarity of the relationship between land use and biological indicators. However, these conventional OLS models cannot provide any insight into local variations in the land use effects within watersheds. Here, we compared the performance of the OLS and GWR statistical models applied to benthic diatom, macroinvertebrate, and fish communities in sub-watershed management areas. We extracted land use datasets from the Ministry of Environment LULC map and data on biological indicators in Nakdong river systems from the National Aquatic Ecological Monitoring Program in Korea. We found that the GWR model had superior performance compared with the OLS model, as assessed based on R2, Akaike’s Information Criterion, and Moran’s I values. Furthermore, GWR models revealed specific localized effects of land use on biological indicators, which we investigated further. The results of this study can be used to inform more effective policies on watershed management and to enhance ecological integrity by prioritizing sub-watershed management areas

  2. Environmental impacts of renewable energy. Geographic Information Systems (GIS) based analysis of cumulative effects; Umweltauswirkungen erneuerbarer Energien. GIS-gestuetzte Analyse kumulativer Wirkungen

    Energy Technology Data Exchange (ETDEWEB)

    Rhoden, Henning

    2015-04-15

    The energy transition and thus turning away from fossil fuels and nuclear energy sources is based on an increased expansion of renewable energies. This expansion mainly take place in nature and the landscape, which conflicts with the objectives of the Federal Nature Conservation Act concerning scenery or the consequences of monoculture cultivation of energy crops. What happens, however, if more than one type of renewables occur compressed in a landscape that is investigated in this work. Result from cumulative effects are extended conflict with the objectives of the Federal Nature Conservation Act or possibly have positive effects can be seen? A ''cumulative effect'' is defined as an additive-synergistic overall effect of all a protected interest of respective impact factors. These arise from one or more projects / plans and influence from a variety of ways. As part of the investigations carried out it is clear that extended conflicts may arise in relation to the objectives of the Federal Nature Conservation Act by cumulative effects of renewable energies. To prevent these conflicts, policies and regulations in the context of spatial planning is necessary to enable a focusing of spatial planning for a sustainable expansion of renewable energy. [German] Die Energiewende und damit die Abkehr von fossilen und atomaren Energiequellen beruht auf einem verstaerkten Ausbau der erneuerbaren Energien. Dieser Ausbau findet vorwiegend in Natur und Landschaft statt, wobei Konflikte mit den Zielen des BNatSchG z.B. hinsichtlich Landschaftsbild oder den Folgen von Monokultur beim Energiepflanzenanbau bereits gegeben sind. Was jedoch passiert, wenn mehrere Arten erneuerbarer Energien in einer Landschaft komprimiert auftreten, wird in dieser Arbeit untersucht. Ergeben sich aus kumulierten Wirkungen erweiterte Konflikte mit den Zielen des BNatSchG oder sind moeglicherweise positive Effekte zu erkennen? Eine ''kumulative Wirkung'' ist

  3. Effects of preferential flow on soil-water and surface runoff in a forested watershed in China

    Institute of Scientific and Technical Information of China (English)

    Jinhua CHENG; Hongjiang ZHANG; Youyan ZHANG; Yuhu SHI; Yun CHENG

    2009-01-01

    Preferential flow is a runoff mechanism intermediate between matrix flow and surface flow, transmitting water at high velocity through the subsurface zone. To assess the effect of preferential flow on soil-water flow and surface runoff in a forested watershed, precipitation and volumes of preferential flow, matrix flow and surface runoff were measured over a period of four years in a forested watershed in the Three Gorges area of southern China. Results show that preferential-flow hydrographs have gentler rises and steeper recessions than those for matrix flow and surface runoff. Preferential flow as a percentage of soil-water flow ranged from 2.40% to 8.72% and the maximum preferential-flow velocity exceeded as much as 5600 times that of matrix flow. This shows that preferential flow plays an important role in the movement of soil water. Preferential flow has a significant effect on peak surface runoff by increasing the surface runoff rate and accelerating the appearance of peak surface runoff. Preferential flow can also prolong the duration of surface runoff. Surface runoff was observed to be positively correlated with preferential flow. The greater the sum of rainfall amount and antecedent precipitation is, the greater the effect of preferential flow on surface runoff is.

  4. Holistic impact assessment and cost savings of rainwater harvesting at the watershed scale

    Directory of Open Access Journals (Sweden)

    Santosh R. Ghimire

    2017-03-01

    Full Text Available We evaluated the impacts of domestic and agricultural rainwater harvesting (RWH systems in three watersheds within the Albemarle-Pamlico river basin (southeastern U.S. using life cycle assessment (LCA and life cycle cost assessment. Life cycle impact assessment (LCIA categories included energy demand, fossil fuel, metals, ozone depletion, global warming, acidification, smog, blue and green water use, ecotoxicity, eutrophication, and human health effects. Building upon previous LCAs of near-optimal domestic and agricultural RWH systems in the region, we scaled functional unit LCIA scores for adoption rates of 25%, 50%, 75%, and 100% and compared these to conventional municipal water and well water systems. In addition to investigating watershed-scale impacts of RWH adoption, which few studies have addressed, potential life cycle cost savings due to reduced cumulative energy demand were scaled in each watershed for a more comprehensive analysis. The importance of managing the holistic water balance, including blue water (surface/ground water, green water (rainwater use, and annual precipitation and their relationship to RWH are also addressed. RWH contributes to water resource sustainability by offsetting surface and ground water consumption and by reducing environmental and human health impacts compared to conventional sources. A watershed-wide RWH adoption rate of 25% has a number of ecological and human health benefits including blue water use reduction ranging from 2–39 Mm3, cumulative energy savings of 12–210 TJ, and reduced global warming potential of 600–10,100 Mg CO2 eq. Potential maximum lifetime energy cost savings were estimated at $5M and $24M corresponding to domestic RWH in Greens Mill and agricultural RWH in Back Creek watersheds.

  5. A simple scoring system for predicting early major complications in spine surgery: the cumulative effect of age and size of surgery.

    Science.gov (United States)

    Brasil, Albert Vincent Berthier; Teles, Alisson R; Roxo, Marcelo Ricardo; Schuster, Marcelo Neutzling; Zauk, Eduardo Ballverdu; Barcellos, Gabriel da Costa; Costa, Pablo Ramon Fruett da; Ferreira, Nelson Pires; Kraemer, Jorge Luiz; Ferreira, Marcelo Paglioli; Gobbato, Pedro Luis; Worm, Paulo Valdeci

    2016-10-01

    To analyze the cumulative effect of risk factors associated with early major complications in postoperative spine surgery. Retrospective analysis of 583 surgically-treated patients. Early "major" complications were defined as those that may lead to permanent detrimental effects or require further significant intervention. A balanced risk score was built using multiple logistic regression. Ninety-two early major complications occurred in 76 patients (13%). Age > 60 years and surgery of three or more levels proved to be significant independent risk factors in the multivariate analysis. The balanced scoring system was defined as: 0 points (no risk factor), 2 points (1 factor) or 4 points (2 factors). The incidence of early major complications in each category was 7% (0 points), 15% (2 points) and 29% (4 points) respectively. This balanced scoring system, based on two risk factors, represents an important tool for both surgical indication and for patient counseling before surgery.

  6. Evaluating the effectiveness of management practices on hydrology and water quality at watershed scale with a rainfall-runoff model.

    Science.gov (United States)

    Liu, Yaoze; Bralts, Vincent F; Engel, Bernard A

    2015-04-01

    The adverse influence of urban development on hydrology and water quality can be reduced by applying best management practices (BMPs) and low impact development (LID) practices. This study applied green roof, rain barrel/cistern, bioretention system, porous pavement, permeable patio, grass strip, grassed swale, wetland channel, retention pond, detention basin, and wetland basin, on Crooked Creek watershed. The model was calibrated and validated for annual runoff volume. A framework for simulating BMPs and LID practices at watershed scales was created, and the impacts of BMPs and LID practices on water quantity and water quality were evaluated with the Long-Term Hydrologic Impact Assessment-Low Impact Development 2.1 (L-THIA-LID 2.1) model for 16 scenarios. The various levels and combinations of BMPs/LID practices reduced runoff volume by 0 to 26.47%, Total Nitrogen (TN) by 0.30 to 34.20%, Total Phosphorus (TP) by 0.27 to 47.41%, Total Suspended Solids (TSS) by 0.33 to 53.59%, Lead (Pb) by 0.30 to 60.98%, Biochemical Oxygen Demand (BOD) by 0 to 26.70%, and Chemical Oxygen Demand (COD) by 0 to 27.52%. The implementation of grass strips in 25% of the watershed where this practice could be applied was the most cost-efficient scenario, with cost per unit reduction of $1m3/yr for runoff, while cost for reductions of two pollutants of concern was $445 kg/yr for Total Nitrogen (TN) and $4871 kg/yr for Total Phosphorous (TP). The scenario with very high levels of BMP and LID practice adoption (scenario 15) reduced runoff volume and pollutant loads from 26.47% to 60.98%, and provided the greatest reduction in runoff volume and pollutant loads among all scenarios. However, this scenario was not as cost-efficient as most other scenarios. The L-THIA-LID 2.1 model is a valid tool that can be applied to various locations to help identify cost effective BMP/LID practice plans at watershed scales.

  7. A paradox of cumulative culture.

    Science.gov (United States)

    Kobayashi, Yutaka; Wakano, Joe Yuichiro; Ohtsuki, Hisashi

    2015-08-21

    Culture can grow cumulatively if socially learnt behaviors are improved by individual learning before being passed on to the next generation. Previous authors showed that this kind of learning strategy is unlikely to be evolutionarily stable in the presence of a trade-off between learning and reproduction. This is because culture is a public good that is freely exploited by any member of the population in their model (cultural social dilemma). In this paper, we investigate the effect of vertical transmission (transmission from parents to offspring), which decreases the publicness of culture, on the evolution of cumulative culture in both infinite and finite population models. In the infinite population model, we confirm that culture accumulates largely as long as transmission is purely vertical. It turns out, however, that introduction of even slight oblique transmission drastically reduces the equilibrium level of culture. Even more surprisingly, if the population size is finite, culture hardly accumulates even under purely vertical transmission. This occurs because stochastic extinction due to random genetic drift prevents a learning strategy from accumulating enough culture. Overall, our theoretical results suggest that introducing vertical transmission alone does not really help solve the cultural social dilemma problem. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Effects of soil and water conservation on crop productivity: Evidences from Anjenie watershed, Ethiopia

    Science.gov (United States)

    Adgo, Enyew; Teshome, Akalu

    2014-05-01

    Widespread soil and water conservation activities have been implemented in many parts of eastern Africa to control soil erosion by water and improve land productivity for the last few decades. Following the 1974 severe drought, soil and water conservation became more important to Ethiopia and the approach shifted to watershed based land management initiatives since the 1980s. To capture long-term impacts of these initiatives, a study was conducted in Anjenie Watershed of Ethiopia, assessing fanya juu terraces and grass strips constructed in a pilot project in 1984, and which are still functional nearly 30 years later. Data were collected from government records, field observations and questionnaire surveys administered to 60 farmers. Half of the respondents had terraced farms in the watershed former project area (with terrace technology) and the rest were outside the terraced area. The crops assessed were teff, barley and maize. Cost-benefit analyses were used to determine the economic benefits with and without terraces, including gross and net profit values, returns on labour, water productivity and impacts on poverty. The results indicated that soil and water conservation had improved crop productivity. The average yield on terraced fields was 0.95 t ha-1 for teff (control 0.49), 1.86 t ha-1 for barley (control 0.61), and 1.73 t ha-1 for maize (control 0.77). The net benefit was significantly higher on terraced fields, recording US 20.9 (US -112 control) for teff, US 185 (US -41 control) for barley and US -34.5 (US - 101 control) ha-1 yr-1 for maize. The returns on family labour were 2.33 for barley, 1.01 for teff, and 0.739 US per person-day for maize grown on terraced plots, compared to US 0.44, 0.27 and 0.16 per person-day for plots without terraces, respectively. Using a discount rate of 10%, the average net present value (NPV) of barley production with terrace was found to be about US 1542 over a period of 50 years. In addition, the average financial

  9. Isotopic studies in Pacific Panama mangrove estuaries reveal lack of effect of watershed deforestation on food webs.

    Science.gov (United States)

    Viana, Inés G; Valiela, Ivan; Martinetto, Paulina; Monteiro Pierce, Rita; Fox, Sophia E

    2015-02-01

    Stable isotopic N, C, and S in food webs of 8 mangrove estuaries on the Pacific coast of Panama were measured to 1) determine whether the degree of deforestation of tropical forests on the contributing watersheds was detectable within the estuarine food web, and 2) define external sources of the food webs within the mangrove estuaries. Even though terrestrial rain forest cover on the contributing watersheds differed between 23 and 92%, the effect of deforestation was not detectable on stable isotopic values in food webs present at the mouth of the receiving estuaries. We used stable isotopic measures to identify producers or organic sources that supported the estuarine food web. N isotopic values of consumers spanned a broad range, from about 2.7 to 12.3‰. Mean δ(15)N of primary producers and organic matter varied from 3.3 for macroalgae to 4.7‰ for suspended particulate matter and large particulate matter. The δ(13)C consumer data varied between -26 and -9‰, but isotopic values of the major apparent producers or organic matter sampled could not account for this range variability. The structure of the food web was clarified when we added literature isotopic values of microphytobenthos and coralline algae, suggesting that these, or other producers with similar isotopic signature, may be part of the food webs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Atmospheric deposition and watershed nitrogen export along an elevational gradient in the Catskill Mountains, New York

    Science.gov (United States)

    Lawrence, G.B.; Lovett, Gary M.; Baevsky, Y.H.

    2000-01-01

    Cumulative effects of atmospheric N deposition may increase N export from watersheds and contribute to the acidification of surface waters, but natural factors (such as forest productivity and soil drainage) that affect forest N cycling can also control watershed N export. To identify factors that are related to stream-water export of N, elevational gradients in atmospheric deposition and natural processes were evaluated in a steep, first-order watershed in the Catskill Mountains of New York, from 1991 to 1994. Atmospheric deposition of SO4/2-, and probably N, increased with increasing elevation within this watershed. Stream-water concentrations of SO4/2- increased with increasing elevation throughout the year, whereas stream-water concentrations of NO3/- decreased with increasing elevation during the winter and spring snowmelt period, and showed no relation with elevation during the growing season or the fall. Annual export of N in stream water for the overall watershed equaled 12% to 17% of the total atmospheric input on the basis of two methods of estimation. This percentage decreased with increasing elevation, from about 25% in the lowest subwatershed to 7% in the highest subwatershed; a probable result of an upslope increase in the thickness of the surface organic horizon, attributable to an elevational gradient in temperature that slows decomposition rates at upper elevations. Balsam fir stands, more prevalent at upper elevations than lower elevations, may also affect the gradient of subwatershed N export by altering nitrification rates in the soil. Variations in climate and vegetation must be considered to determine how future trends in atmospheric deposition will effect watershed export of nitrogen.

  11. Pioneering water quality data on the Lake Victoria watershed: effects on human health.

    Science.gov (United States)

    Jovanelly, Tamie J; Johnson-Pynn, Julie; Okot-Okumu, James; Nyenje, Richard; Namaganda, Emily

    2015-09-01

    Four forest reserves within 50 km of Kampala in Uganda act as a critical buffer to the Lake Victoria watershed and habitat for local populations. Over a 9-month period we capture a pioneering water quality data set that illustrates ecosystem health through the implementation of a water quality index (WQI). The WQI was calculated using field and laboratory data that reflect measured physical and chemical parameters (pH, dissolved oxygen, biological oxygen on demand, nitrates, phosphates, fecal coliform, and temperature turbidity). Overall, the WQI for the four forest reserves reflect poor to medium water quality. Results compared with US Environmental Protection Agency and World Health Organization drinking water standards indicate varying levels of contamination at most sites and all designated drinking water sources, with signatures of elevated nitrates, phosphates, and/or fecal coliforms. As critical health problems are known to arise with elevated exposure to contaminants in drinking water, this data set can be used to communicate necessary improvements within the watershed.

  12. Techniques for detecting effects of urban and rural land-use practices on stream-water chemistry in selected watersheds in Texas, Minnesota,and Illinois

    Science.gov (United States)

    Walker, J.F.

    1993-01-01

    Although considerable effort has been expended during the past two decades to control nonpoint-source contamination of streams and lakes in urban and rural watersheds, little has been published on the effectiveness of various management practices at the watershed scale. This report presents a discussion of several parametric and nonparametric statistical techniques for detecting changes in water-chemistry data. The need for reducing the influence of natural variability was recognized and accomplished through the use of regression equations. Traditional analyses have focused on fixed-frequency instantaneous concentration data; this report describes the use of storm load data as an alternative.

  13. Landscape characterization for watershed management

    Energy Technology Data Exchange (ETDEWEB)

    Hunsaker, C.T.; Jackson, B.L. [Oak Ridge National Lab., TN (United States); Schwartz, P.M. [Oak Ridge Institute for Science Education, Oak Ridge, TN (United States)

    1996-07-01

    Streams and rivers serve as integrators of terrestrial landscape characteristics and as recipients of pollutants from both the atmosphere and the land; thus, large rivers are especially good indicators of cumulative impacts. Landscape ecologists seek to better understand the relationships between landscape structure and ecosystem processes at various spatial scales. Understanding how scale, both data resolution and geographic extent, influences landscape characterization and how terrestrial processes affect water quality are critically important for model development and translation of research results from experimental watersheds to management of large drainage basins. Measures of landscape structure are useful to monitor change and assess the risks it poses to ecological resources. Many studies have shown that the proportion of different land uses within a watershed can account for some of the variability in surface water quality. Hunsaker and Levine showed that both proportion of land uses and the spatial pattern of land uses is important for characterizing and modeling water quality; however, proportion consistently accounted for the most variance (40% to 86%) across a range of watershed sizes (1000 to 1.35 million ha). The U.S. Environmental Protection Agency (EPA) is performing a demonstration of its Environmental Monitoring and Assessment Program (EMAP) for the Mid-Atlantic Region. One activity, the Mid-Atlantic Integrated Assessment, is designed as a collaborative initiative between EPA`s Office of Research and Development and EPA`s Region III.

  14. Effect of vitamin B supplementation on cancer incidence, death due to cancer, and total mortality: A PRISMA-compliant cumulative meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Zhang, Sui-Liang; Chen, Ting-Song; Ma, Chen-Yun; Meng, Yong-Bin; Zhang, Yu-Fei; Chen, Yi-Wei; Zhou, Yu-Hao

    2016-08-01

    Observational studies have suggested that vitamin B supplementation is associated with cancer risk, but this association remains controversial. A pooled data-based meta-analysis was conducted to summarize the evidence from randomized controlled trials (RCTs) investigating the effects of vitamin B supplementation on cancer incidence, death due to cancer, and total mortality. PubMed, EmBase, and the Cochrane Library databases were searched to identify trials to fit our analysis through August 2015. Relative risk (RR) was used to measure the effect of vitamin B supplementation on the risk of cancer incidence, death due to cancer, and total mortality using a random-effect model. Cumulative meta-analysis, sensitivity analysis, subgroup analysis, heterogeneity tests, and tests for publication bias were also conducted. Eighteen RCTs reporting the data on 74,498 individuals were included in the meta-analysis. Sixteen of these trials included 4103 cases of cancer; in 6 trials, 731 cancer-related deaths occurred; and in 15 trials, 7046 deaths occurred. Vitamin B supplementation had little or no effect on the incidence of cancer (RR: 1.04; 95% confidence interval [CI]: 0.98-1.10; P = 0.216), death due to cancer (RR, 1.05; 95% CI: 0.90-1.22; P = 0.521), and total mortality (RR, 1.00; 95% CI: 0.94-1.06; P = 0.952). Upon performing a cumulative meta-analysis for cancer incidence, death due to cancer, and total mortality, the nonsignificance of the effect of vitamin B persisted. With respect to specific types of cancer, vitamin B supplementation significantly reduced the risk of skin melanoma (RR, 0.47; 95% CI: 0.23-0.94; P = 0.032). Vitamin B supplementation does not have an effect on cancer incidence, death due to cancer, or total mortality. It is associated with a lower risk of skin melanoma, but has no effect on other cancers.

  15. Comparison of the effect of glycerol and triamcinolone acetonide on cumulative skin irritation in a randomized trial

    DEFF Research Database (Denmark)

    Andersen, Flemming; Hedegaard, Kathryn; Petersen, Thomas Kongstad

    2007-01-01

    BACKGROUND: So-called anti-irritants are added to cosmetic formulations because of their alleged beneficial effect on irritated skin. Documentation for these claims is often limited. However, glycerol has shown anti-irritant properties in experimentally induced irritation from sodium lauryl sulfate...... and nonanoic acid (NON). This study was designed to further substantiate that glycerol added to cosmetic formulations has an anti-irritant effect on experimentally induced skin irritation. OBJECTIVE: We sought to compare glycerol with triamcinolone acetonide as treatments for cutaneous irritation in human....... The treatments (including vehicle and no treatment) were randomized to sites using a Latin square design. The reactions were evaluated clinically and instrumentally. LIMITATIONS: Study was designed to only detect potent anti-irritants. CONCLUSION: Glycerol reduced the irritant effect of both sodium lauryl...

  16. Statewide Watershed Protection and Local Implementation: A Comparison of Washington, Minnesota, and Oregon

    OpenAIRE

    1999-01-01

    Abstract In 1991 EPA embraced the watershed protection approach for environmental management. EPA defines watershed protection as â a strategy for effectively protecting and restoring aquatic ecosystems and protecting human health.â To encourage statewide watershed protection, EPA developed the â Statewide Watershed Protection Approachâ document, which is designed to aid states in developing their own watershed protection program. The watershed protection approach is n...

  17. Cumulative Effects of Prenatal Substance Exposure and Early Adversity on Foster Children's HPA-Axis Reactivity during a Psychosocial Stressor

    Science.gov (United States)

    Fisher, Philip A.; Kim, Hyoun K.; Bruce, Jacqueline; Pears, Katherine C.

    2012-01-01

    Dysregulated hypothalamic-pituitary-adrenocortical (HPA) axis stress response has been reported among individuals with prenatal substance exposure and those with early adversity exposure. However, few researchers have examined the combined effects of these risk factors. Patterns of HPA reactivity among maltreated foster children with and without…

  18. Cumulative Effects of Prenatal Substance Exposure and Early Adversity on Foster Children's HPA-Axis Reactivity during a Psychosocial Stressor

    Science.gov (United States)

    Fisher, Philip A.; Kim, Hyoun K.; Bruce, Jacqueline; Pears, Katherine C.

    2012-01-01

    Dysregulated hypothalamic-pituitary-adrenocortical (HPA) axis stress response has been reported among individuals with prenatal substance exposure and those with early adversity exposure. However, few researchers have examined the combined effects of these risk factors. Patterns of HPA reactivity among maltreated foster children with and without…

  19. Effectiveness of timber harvesting BMPs: monitoring spatial and temporal dynamics of dissolved oxygen, nitrogen, and phosphorus in a low-gradient watershed, Louisiana

    Science.gov (United States)

    Abram DaSilva; Y. Jun Xu; George Ice; John Beebe; Richard Stich

    2012-01-01

    To test effectiveness of Louisiana’s voluntary best management practices (BMPs) at preventing water quality degradation from timber harvesting activities, a study with BACI design was conducted from 2006 through 2010 in the Flat Creek Watershed, north-central Louisiana. Water samples for nutrient analyses and measurements of stream flow and of in-stream dissolved...

  20. Assessing the effects of land cover and future climate conditions on the provision of hydrological services in a medium-sized watershed of Portugal

    NARCIS (Netherlands)

    Carvalho-Santos, Claudia; Nunes, João Pedro; Monteiro, António T.; Hein, Lars; Honrado, João Pradinho

    2016-01-01

    The separated and combined effects of land-cover scenarios and future climate on the provision of hydrological services were evaluated in Vez watershed, northern Portugal. Soil and Water Assessment Tool was calibrated against daily discharge, sediments and nitrates, with good agreements between m

  1. Evaluating the effect of land use land cover change in a rapidly urbanizing semi-arid watershed on estuarine freshwater inflows

    Science.gov (United States)

    Sahoo, D.; Smith, P.; Popescu, S.

    2006-12-01

    Estuarine freshwater inflows along with their associated nutrient and metal delivery are influenced by the land use/land cover (LULC) and water management practices in the contributing watershed. This study evaluates the effect of rapid urbanization in the San Antonio River Watershed on the amount of freshwater inflow reaching the San Antonio-Guadalupe estuary on the Gulf Coast of Texas. Remotely sensed data from satellite imagery provided a source of reliable data for land use classification and land cover change analysis; while long time series of the geophysical signals of stream flow and precipitation provided the data needed to assess change in flow in the watershed. LULC was determined using LANDSAT (5 TM and 7 ETM) satellite images over 20 years (1985-2003). The LANDSAT images were classified using an ENVI. ISODATA classification scheme. Changes were quantified in terms of the urban expansion that had occurred in past 20 years using an urban index. Streamflow was analyzed using 20 years (1985-2004) of average daily discharge obtained from the USGS gauging station (08188500) closest to the headwaters of the estuary. Baseflow and storm flow were partitioned from total flow using a universally used baseflow separation technique. Precipitation data was obtained from an NCDC station in the watershed. Preliminary results indicate that the most significant change in land use over the 20 year period was an increase in the total amount of impervious area in the watershed. This increase in impervious area was accompanied by an increase in both total streamflow and in baseflow over the same period. The investigation did not show a significant change in total annual precipitation from 1990 to 2004. This suggests that the increase in streamflow was more influenced by LULC than climate change. One explanation for the increase in baseflow may be an increase in return flows resulting from an increase in the total number of wastewater treatment plants in the watershed.

  2. An Evidence-Based Evaluation of the Cumulative Effects of Tidal Freshwater and Estuarine Ecosystem Restoration on Endangered Juvenile Salmon in the Columbia River: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Diefenderfer, Heida L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Gary E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Thom, Ronald M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Borde, Amy B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Woodley, Christa M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weitkamp, Laurie A. [Marine Sciences lab., Sequim, WA (United States); Buenau, Kate E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kropp, Roy K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-12-01

    The listing of 13 salmon and steelhead stocks in the Columbia River basin (hereafter collectively referred to as “salmon”) under the Endangered Species Act of 1973, as amended, has stimulated tidal wetland restoration in the lower 235 kilometers of the Columbia River and estuary for juvenile salmon habitat functions. The purpose of the research reported herein was to evaluate the effect on listed salmon of the restoration effort currently being conducted under the auspices of the federal Columbia Estuary Ecosystem Restoration Program (CEERP). Linking changes in the quality and landscape pattern of tidal wetlands in the lower Columbia River and estuary (LCRE) to salmon recovery is a complex problem because of the characteristics of the ecosystem, the salmon, the restoration actions, and available sampling technologies. Therefore, we designed an evidence-based approach to develop, synthesize, and evaluate information to determine early-stage (~10 years) outcomes of the CEERP. We developed an ecosystem conceptual model and from that, a primary hypothesis that habitat restoration activities in the LCRE have a cumulative beneficial effect on juvenile salmon. There are two necessary conditions of the hypothesis: • habitat-based indicators of ecosystem controlling factors, processes, and structures show positive effects from restoration actions, and • fish-based indicators of ecosystem processes and functions show positive effects from restoration actions and habitats undergoing restoration. Our evidence-based approach to evaluate the primary hypothesis incorporated seven lines of evidence, most of which are drawn from the LCRE. The lines of evidence are spatial and temporal synergies, cumulative net ecosystem improvement, estuary-wide meta-analysis, offsite benefits to juvenile salmon, landscape condition evaluation, and evidence-based scoring of global literature. The general methods we used to develop information for the lines of evidence included field

  3. Cumulative release characteristics of controlled-release nitrogen and potassium fertilizers and their effects on soil fertility, and cotton growth

    OpenAIRE

    Xiuyi Yang; Jibiao Geng; Chengliang Li; Min Zhang; Xiaofei Tian

    2016-01-01

    To investigate the interacting effects of polymer coated urea (PCU) and polymer coated potassium chloride (PCPC) on cotton growth, an experiment was conducted with containerized plants in 2014 and 2015. There were two kinds of nitrogen fertilizer, PCU and urea, which were combined with PCPC at three application rates (40, 80 and 120 kg ha−1). The kinds of nitrogen fertilizer formed the main plot, while individual rates of PCPC were the subplots. The results suggested N and K release patterns ...

  4. Child Maltreatment, Impulsivity, and Antisocial Behavior in African-American Children: Moderation Effects from a Cumulative Dopaminergic Gene Index

    Science.gov (United States)

    Thibodeau, Eric L.; Cicchetti, Dante; Rogosch, Fred A.

    2015-01-01

    A model examining the effects of an increasing number of maltreatment subtypes experienced on antisocial behavior, as mediated by impulsivity and moderated by a polygenic index of dopaminergic genotypes, was investigated. An African American sample of children (N = 1012, M age = 10.07) with and without maltreatment histories participated. Indicators of aggression, delinquency, and disruptive peer behavior were obtained from peer and counselor rated measures to form a latent variable of antisocial behavior; impulsivity was assessed by counselor report. Five genotypes in four dopaminergic genes (DRD4, DRD2, DAT1, and COMT) conferring heightened environmental sensitivity were combined into one polygenic index. Using SEM, a first-stage, moderated-mediation model was evaluated. Age and sex were entered as covariates, both as main effects and in interaction with maltreatment and the gene index. The model had excellent fit: χ2(32, N =1012) = 86..51, p<0.001; CFI = 0.982; TLI = 0.977; RMSEA = 0.041; SRMR = 0.022. The effect of maltreatment subtypes on antisocial behavior was partially mediated by impulsivity (β= 0.173, p<0.001), and these relations were moderated by the number of differentiating dopaminergic genotypes. Specifically, a significant GxE interaction (b = 0.016, p = 0.013) indicated that the relation between maltreatment and impulsivity was stronger as children evinced more differentiating genotypes, thereby strengthening the mediational effect of impulsivity on antisocial behavior. These findings elucidate the manner by which maltreated children develop early signs of antisocial behavior, and the genetic mechanisms involved in greater vulnerability for maladaptation in impulse-control within context of child maltreatment. PMID:26535948

  5. Cumulative release characteristics of controlled-release nitrogen and potassium fertilizers and their effects on soil fertility, and cotton growth

    OpenAIRE

    Xiuyi Yang; Jibiao Geng; Chengliang Li; Min Zhang; Xiaofei Tian

    2016-01-01

    To investigate the interacting effects of polymer coated urea (PCU) and polymer coated potassium chloride (PCPC) on cotton growth, an experiment was conducted with containerized plants in 2014 and 2015. There were two kinds of nitrogen fertilizer, PCU and urea, which were combined with PCPC at three application rates (40, 80 and 120 kg ha−1). The kinds of nitrogen fertilizer formed the main plot, while individual rates of PCPC were the subplots. The results suggested N and K release patterns ...

  6. Child maltreatment, impulsivity, and antisocial behavior in African American children: Moderation effects from a cumulative dopaminergic gene index.

    Science.gov (United States)

    Thibodeau, Eric L; Cicchetti, Dante; Rogosch, Fred A

    2015-11-01

    A model examining the effects of an increasing number of maltreatment subtypes experienced on antisocial behavior, as mediated by impulsivity and moderated by a polygenic index of dopaminergic genotypes, was investigated. An African American sample of children (N = 1,012, M age = 10.07) with and without maltreatment histories participated. Indicators of aggression, delinquency, and disruptive peer behavior were obtained from peer- and counselor-rated measures to form a latent variable of antisocial behavior; impulsivity was assessed by counselor report. Five genotypes in four dopaminergic genes (dopamine receptors D4, D2, known as DRD4, DRD2; dopamine active transporter 1, known as DAT1; and catechol-O-methyltransferase, known as COMT) conferring heightened environmental sensitivity were combined into one polygenic index. Using structural equation modeling, a first-stage, moderated-mediation model was evaluated. Age and sex were entered as covariates, both as main effects and in interaction with maltreatment and the gene index. The model had excellent fit: χ2 (32, N = 1,012) = 86.51, p impulsivity (β = 0.173, p impulsivity was stronger as children evinced more differentiating genotypes, thereby strengthening the mediational effect of impulsivity on antisocial behavior. These findings elucidate the manner by which maltreated children develop early signs of antisocial behavior, and the genetic mechanisms involved in greater vulnerability for maladaptation in impulse control within the context of child maltreatment.

  7. Acute and cumulative effects of focused high-frequency vibrations on the endocrine system and muscle strength.

    Science.gov (United States)

    Iodice, Pierpaolo; Bellomo, Rosa Grazia; Gialluca, Glaugo; Fanò, Giorgio; Saggini, Raoul

    2011-06-01

    The purpose of this study was to evaluate the acute and long-term effects of local high-intensity vibration (HLV, f = 300 Hz) on muscle performance and blood hormone concentrations in healthy young men. Totally 18 subjects (cV group) were studied in two sessions, either without (control) or with HLV treatment. The protocol was the same on both control and test days, except that, in the second session, subjects underwent HLV treatment. Counter-movement jumping (CMJ), maximal isometric voluntary contraction (MVC) test, and hormonal levels were measured before the procedure, immediately thereafter, and 1 h later. To assess the long-term effects of HLV, the cV group was subjected to HLV on the leg muscles for 4 weeks, and a second group (cR group, n = 18) embarked upon a resistance training program. All subjects underwent an MVC test and an isokinetic (100 deg/s) test before training, 4 weeks after training, and 2 months after the end of training. The HLV protocol significantly increased the serum level of growth hormone (GH, P neuromuscular performance. Our results indicate that HLV has a long-term beneficial effect comparable to that of resistance training.

  8. Watershed Management Optimization Support Tool (WMOST) v2: Theoretical Documentation

    Science.gov (United States)

    The Watershed Management Optimization Support Tool (WMOST) is a decision support tool that evaluates the relative cost-effectiveness of management practices at the local or watershed scale. WMOST models the environmental effects and costs of management decisions in a watershed c...

  9. Study on the Topographic Effect on Soil Erosion Using RUSLE Model for Small Size Watershed

    Institute of Scientific and Technical Information of China (English)

    CHEN Chuan-sheng; JIANG Xin

    2006-01-01

    Soil erosion and subsequent sedimentation have caused serious environmental and soil degradation problems in Okinawa Prefecture, Japan. This research aims at evaluating an availability of the Revised Universal Soil loss Equation (RUSLE) for predicting the range of soil loss values for the Nago watershed in Okinawa. It shows that climatic conditions substantially influence the rainfall amount as a function of the I30 of the rainfall event. The rate of soil loss is higher with increasing in altitude due to greater slope steepness. By rainfall data analysis, it is concluded that the large difference in soil loss between 2000 and 2001 was due to concentrated heavy rainfall in the rainy season or the typhoon season.

  10. Cumulative neurobehavioral and physiological effects of chronic caffeine intake: individual differences and implications for the use of caffeinated energy products.

    Science.gov (United States)

    Spaeth, Andrea M; Goel, Namni; Dinges, David F

    2014-10-01

    The use of caffeine-containing energy products has increased worldwide in recent years. All of the top-selling energy drinks contain caffeine, which is likely to be the primary psychoactive ingredient in these products. Research shows that caffeine-containing energy products can improve cognitive and physical performance. Presumably, individuals consume caffeine-containing energy products to counteract feelings of low energy in situations causing tiredness, fatigue, and/or reduced alertness. This review discusses the scientific evidence for sleep loss, circadian phase, sleep inertia, and the time-on-task effect as causes of low energy and summarizes research assessing the efficacy of caffeine to counteract decreased alertness and increased fatigue in such situations. The results of a placebo-controlled experiment in healthy adults who had 3 nights of total sleep deprivation (with or without 2-hour naps every 12 hours) are presented to illustrate the physiological and neurobehavioral effects of sustained low-dose caffeine. Individual differences, including genetic factors, in the response to caffeine and to sleep loss are discussed. The review concludes with future directions for research on this important and evolving topic.

  11. Assessment of aquifer properties, evapotranspiration, and the effects of ditching in the Stoney Brook watershed, Fond du Lac Reservation, Minnesota, 2006-9

    Science.gov (United States)

    Jones, Perry M.; Tomasek, Abigail A.

    2015-01-01

    The U.S. Geological Survey, in cooperation with the Fond du Lac Band of Lake Superior Chippewa, assessed hydraulic properties of geologic material, recharge, and evapotranspiration, and the effects of ditching on the groundwater resources in the Stoney Brook watershed in the Fond du Lac Reservation. Geologic, groundwater, and surface-water data were collected during 2006–9 to estimate hydrologic properties in the watershed. Streamflow and groundwater levels in the shallow glacial deposits in the Stoney Brook watershed were analyzed to estimate groundwater-flow directions, groundwater recharge, and evapotranspiration within the watershed and to assess the effect of ditches on surrounding groundwater resources. Groundwater, streamflow, and precipitation data collected during the study (2006–9) can be used to update the U.S. Department of Agriculture’s Natural Resource Conservation Service and Fond du Lac Resource Management Division surface-water models, which are used to evaluate the effect of proposed adjustments to the ditching system on streamflow on wild rice production and aquatic habitats.

  12. Electrical-modelling, design and simulation of cumulative radiation effects in semiconductor pixels detectors: prospects and limits

    CERN Document Server

    Fourches, Nicolas T; Chipaux, Rémi

    2014-01-01

    Silicon detectors have gained in popularity since silicon became a widely used micro/nanoelectronic semiconductor material. Silicon detectors are used in particle physics as well as imaging for pixel based detecting systems. Over the past twenty years a lot of experimental efforts have been focused on the effects of ionizing and non-ionizing radiation on silicon pixels. Some of this research was done in the framework of high luminosity particle physics experiments, along with radiation hardness studies of basic semiconductors devices. In its simplest form the semiconductor pixel detectors reduce to a PIN or PN structure partially or totally depleted, or in some MOS and APD (Avalanche PhotoDiode) structures. Bulk or surface defects affect considerably transport of free carriers. We propose guidelines for pixel design, which will be tested through a few pixel structures. This design method includes into the design the properties of defects. The electrical properties reduce to parameters, which can be introduced...

  13. Effects of climate variability and accelerated forest thinning on watershed-scale runoff in southwestern USA ponderosa pine forests.

    Science.gov (United States)

    Robles, Marcos D; Marshall, Robert M; O'Donnell, Frances; Smith, Edward B; Haney, Jeanmarie A; Gori, David F

    2014-01-01

    The recent mortality of up to 20% of forests and woodlands in the southwestern United States, along with declining stream flows and projected future water shortages, heightens the need to understand how management practices can enhance forest resilience and functioning under unprecedented scales of drought and wildfire. To address this challenge, a combination of mechanical thinning and fire treatments are planned for 238,000 hectares (588,000 acres) of ponderosa pine (Pinus ponderosa) forests across central Arizona, USA. Mechanical thinning can increase runoff at fine scales, as well as reduce fire risk and tree water stress during drought, but the effects of this practice have not been studied at scales commensurate with recent forest disturbances or under a highly variable climate. Modifying a historical runoff model, we constructed scenarios to estimate increases in runoff from thinning ponderosa pine at the landscape and watershed scales based on driving variables: pace, extent and intensity of forest treatments and variability in winter precipitation. We found that runoff on thinned forests was about 20% greater than unthinned forests, regardless of whether treatments occurred in a drought or pluvial period. The magnitude of this increase is similar to observed declines in snowpack for the region, suggesting that accelerated thinning may lessen runoff losses due to warming effects. Gains in runoff were temporary (six years after treatment) and modest when compared to mean annual runoff from the study watersheds (0-3%). Nonetheless gains observed during drought periods could play a role in augmenting river flows on a seasonal basis, improving conditions for water-dependent natural resources, as well as benefit water supplies for downstream communities. Results of this study and others suggest that accelerated forest thinning at large scales could improve the water balance and resilience of forests and sustain the ecosystem services they provide.

  14. Effects of human-induced environmental changes on benthic macroinvertebrate assemblages of wetlands in Lake Tana Watershed, Northwest Ethiopia.

    Science.gov (United States)

    Gezie, Ayenew; Anteneh, Wassie; Dejen, Eshete; Mereta, Seid Tiku

    2017-04-01

    Wetlands of Lake Tana Watershed provide various ecological and socioeconomic functions. However, they are losing their vigor at alarming rate due to unwise management. Hence, there is an urgent need to monitor and assess these resources so as to identify the major drivers of its degradation and to provide information for management decisions. In this context, we aimed to assess the effects of human activities on macroinvertebrate assemblages of wetlands in Lake Tana Watershed. Biotic and abiotic data were collected from 46 sampling sites located in eight wetlands. A total of 2568 macroinvertebrates belonging to 46 families were recorded. Macroinvertebrate metrics such as Biological Monitoring Working Party score, Shannon diversity index, Ephemeroptera and odonata family richness, and total family richness portrayed a clear pattern of decreasing with increasing in human disturbances, whereas Family biotic index score, which is an indicator of organic pollution, increased with increasing in human disturbances. The regression analysis also revealed that livestock grazing, leather tanning, and eucalyptus plantation were important predictors of macroinvertebrate metrics (p wetlands such as farming, leather tanning, solid waste dumping, and effluent discharges were contributed to the degradation of water quality and decreasing in the macroinvertebrate richness and diversity. These alterations could also reduce the availability of wetland products (sedges, craft materials, etc.) and the related ecosystem services. This in turn has an adverse effect on food security and poverty alleviation with considerable impact on communities who heavily depend on wetland products for their livelihood. Therefore, it is essential to formulate wetland policy for achieving wise use goals and necessary legal and institutional backup for sustainable wetland management in Ethiopia.

  15. Using simulation models to investigate the cumulative effects of sowing rate, sowing date and cultivar choice on weed competition.

    Science.gov (United States)

    Andrew, Izzadora K S; Storkey, Jonathan

    2017-05-01

    With the increasing pressure on crop production from the evolution of herbicide resistance, farmers are increasingly adopting Integrated Weed Management (IWM) strategies to augment their weed control. These include measures to increase the competitiveness of the crop canopy such as increased sowing rate and the use of more competitive cultivars. While there are data on the relative impact of these non-chemical weed control methods assessed in isolation, there is uncertainty about their combined contribution, which may be hindering their adoption. In this article, the INTERCOM simulation model of crop/weed competition was used to examine the combined impact of crop density, sowing date and cultivar choice on the outcomes of competition between wheat (Triticum aestivum) and Alopecurus myosuroides. Alopecurus myosuroides is a problematic weed of cereal crops in North-Western Europe and the primary target for IWM in the UK because it has evolved resistance to a range of herbicides. The model was parameterised for two cultivars with contrasting competitive ability, and simulations run across 10 years at different crop densities and two sowing dates. The results suggest that sowing date, sowing density and cultivar choice largely work in a complementary fashion, allowing enhanced competitive ability against weeds when used in combination. However, the relative benefit of choosing a more competitive cultivar decreases at later sowing dates and higher crop densities. Modeling approaches could be further employed to examine the effectiveness of IWM, reducing the need for more expensive and cumbersome long-term in situ experimentation.

  16. Consistent and cumulative effects of syntactic experience in children's sentence production: Evidence for error-based implicit learning.

    Science.gov (United States)

    Branigan, Holly P; Messenger, Katherine

    2016-12-01

    Error-based implicit learning models (e.g., Chang, Dell, & Bock, 2006) propose that a single learning mechanism underlies immediate and long-term effects of experience on children's syntax. We test two key predictions of these models: That individual experiences of infrequent structures should yield both immediate and long-term facilitation, and that such learning should be consistent in individual speakers across time. Children (and adults) described transitive events in two picture-matching games, held a week apart. In both sessions, the experimenter's immediately preceding syntax (active vs. passive) dynamically influenced children's (and adults') syntactic choices in an individually consistent manner. Moreover, children showed long-term facilitation, through an increased likelihood to produce passives in Session 2, with speakers who were most likely to immediately repeat passives in Session 1 being most likely to produce passives in Session 2. Our results are consistent with an error-based syntactic learning mechanism that operates across the lifespan. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Effects of reforestation on the hydrological function of a small watershed in the Three Gorges Reservoir Area

    Institute of Scientific and Technical Information of China (English)

    QI Shi; WANG Yunqi; WANG Yujie

    2007-01-01

    For vegetation communities with hydrological function in the Three Gorges Reservoir Area,the storm event distributed hydrological model Precipitation-Runoff Modeling System (PRMS)-Storm was built based on modular modeling system developed by the US Geological Survey,and was employed to study the effects of forests on peak flows in the Xiangshuixi forest watershed in the Three Gorges Reservoir Area.The results showed that:1) this simulation study suggested that PRMS-Storm can meet the second level national flood prediction standards of China for simulating storm events of small forest watersheds,and can issue flood forecasting;2) hydrological functions of different vegetation communities were evaluated,and three simulation scenarios were arranged:mixed conifer-broadleaf forests (scenario 1),broad-leaved forests (scenario 2),and general forests arrangement (scenario 3);3) the well-arranged forest scenarios can reduce over 20% of surface rtmoff,result in an increase of over 16% in subsurface flow,and decrease peak flow by 20.8%,9.6%,and 18.9%,respectively.The reduction of peak flow rates was significant when rainfall peak was higher than 0.8 mm/min,especially for short-term rainfall events.In general,we found that scenarios 1 and 3 were preferable for reducing peak flow rates and volumes in the reforestation practices in the study region,and scenario 1 was better than scenario 3,so the mixed conifer-broadleaf forests had the best hydrological function.

  18. Improving the effectiveness of interventions and investment in Andean watersheds through a participatory network of research basins

    Science.gov (United States)

    Ochoa-Tocachi, B. F.; Buytaert, W.; De Bièvre, B.

    2016-12-01

    Many watershed interventions in remote data-scarce areas respond to information gaps by extrapolating conventional approaches based on very limited local evidence. However, most interventions, including conservation strategies and adaptation measures, have not been evaluated properly for their hydrological benefits. This is particularly the case for the Andean region, where the complex climatic and hydrological characteristics combined with a very dynamic anthropogenic disturbance, require better monitoring. Here, we present the experience of a partnership of academic and non-governmental institutions who pioneered participatory hydrological monitoring in the Andes. Established in 2009, the Regional Initiative for Hydrological Monitoring of Andean Ecosystems (iMHEA), is a bottom-up initiative that complements the national monitoring networks and more conventional scientific observatories. Using a design based on a trading-space-for-time approach, over 30 paired catchments with a variety of watershed interventions are currently being monitored by 18 local stakeholders in 15 sites in the tropical Andes. Pooling these data into a hydrological impact model allowed the consortium to make more robust predictions about the effectiveness of catchment interventions to improve water resources management and to reduce risks. The collaborative nature of iMHEA has several strengths. We identify as most important of those the ability to: (i) standardize monitoring practices; (ii) ensure quality and technical support; (iii) share responsibility of monitoring activities; (iv) obtain project co-funding and complementarity; and, (v) promote decision maker-scientist engagement. As a result, this network has started to deliver useful information to multi-scale and multi-stakeholder decision making arenas. For example, in the context of growing investment in hydrological ecosystem services in Peru, the sites provide a new generation of hydrological information that allows for evidence

  19. Land use effect and hydrological control on nitrate yield in subtropical mountainous watersheds

    Directory of Open Access Journals (Sweden)

    J.-C. Huang

    2012-03-01

    Full Text Available Nitrate export in small subtropical watersheds is rarely observed and the estimation of individual land use nitrate yield from a mixed combination within catchments has scarcely been studied. In this study the nitrate concentrations at 16 nested catchments in the Chi-Chia-Wan watershed in Central Taiwan were measured during 2007–2008. A 3-layer TOPMODEL was applied to estimate daily discharge for ungauged sub-catchments. The observed nitrate concentrations and the simulated discharges were used for nitrate flux estimations through four flux methods. Meanwhile, a new deconvolution computation was developed to resolve the nitrate yield of each land use from within the mixed combinations.

    The results showed that the observed mean NO3-N concentration in relatively pristine catchments was approximately 0.145 ± 0.103 mg l−1, which is comparable with other forestry catchments around the world. However, the higher rainfall/runoff, substantial N deposition, and other nitrogen sources resulted in significantly higher annual export of approximately 238–1018 kg-N km−2 yr−1. Our deconvolution computation showed that the background yield of natural forestry was ~351 ±62 kg-N km−2 yr−1. On the other hand, the extremely high nitrate yield of active farmland was ~308, 170 ± 19 241 kg-N km−2 yr−1 due to over-fertilization. The deconvolution computation technique is capable of tracing the mixed signals at the outlet back to the nitrate productions from varied land use patterns. It advances the application of river monitoring network. The typical values of nitrate yields can serve as a guideline for land management. Comparing the nitrogen input and output, we found some nitrogen missing in the cycling which may indicate certain removal processes and we therefore suggest further study to be carried out to fully understand nitrogen cycling in

  20. Adopt Your Watershed

    Data.gov (United States)

    U.S. Environmental Protection Agency — Adopt Your Watershed is a Website that encourages stewardship of the nation's water resources and serves as a national inventory of local watershed groups and...

  1. Effects of converting sagebrush cover to grass on the hydrology of small watersheds at Boco Mountain, Colorado

    Science.gov (United States)

    Lusby, Gregg C.

    1979-01-01

    Changes in runoff and sediment yield caused by changing sagebrush cover to grass cover were studied at four small watersheds in western Colorado during a 9-year period, from 1965 to 1978. Measurements of runoff and sediment yield from the four watersheds were made for 8 years, at which time two watersheds were plowed and seeded to beardless bluebunch wheatgrass. The same measurements were then continued for an additional 6 years. Measurements indicated that conversion to grass caused a reduction in runoff from summer rainstorms of about 75 percent. Runoff from spring snowmelt increased about 12 percent, and annual runoff from treated watersheds decreased about 20 percent when compared to control watersheds. Sediment yield from the seeded watersheds was reduced by about 80 percent; most of this reduction is related to the decrease in runoff from summer rainstorms. The size of barren interspaces between plants was reduced on the converted water- sheds to about 30 percent of those on the untreated watersheds. Linear regression analysis indicates that a reduction of 38 percent in the amount of bare soil resulting from planting grass would result in a decrease of 73 percent in sediment concentration.

  2. Effect of variable annual precipitation and nutrient input on nitrogen and phosphorus transport from two Midwestern agricultural watersheds

    Science.gov (United States)

    Kalkhoff, Stephen J.; Hubbard, Laura E.; Tomer, Mark D.; James, D.E.

    2016-01-01

    Precipitation patterns and nutrient inputs affect transport of nitrate (NO3-N) and phosphorus (TP) from Midwest watersheds. Nutrient concentrations and yields from two subsurface-drained watersheds, the Little Cobb River (LCR) in southern Minnesota and the South Fork Iowa River (SFIR) in northern Iowa, were evaluated during 1996–2007 to document relative differences in timings and amounts of nutrients transported. Both watersheds are located in the prairie pothole region, but the SFIR exhibits a longer growing season and more livestock production. The SFIR yielded significantly more NO3-N than the LCR watershed (31.2 versus 21.3 kg NO3-N ha− 1 y− 1). The SFIR watershed also yielded more TP than the LCR watershed (1.13 versus 0.51 kg TP ha− 1 yr− 1), despite greater TP concentrations in the LCR. About 65% of NO3-N and 50% of TP loads were transported during April–June, and < 20% of the annual loads were transported later in the growing season from July–September. Monthly NO3-N and TP loads peaked in April from the LCR but peaked in June from the SFIR; this difference was attributed to greater snowmelt runoff in the LCR. The annual NO3-N yield increased with increasing annual runoff at a similar rate in both watersheds, but the LCR watershed yielded less annual NO3-N than the SFIR for a similar annual runoff. These two watersheds are within 150 km of one another and have similar dominant agricultural systems, but differences in climate and cropping inputs affected amounts and timing of nutrient transport.

  3. Grays River Watershed Geomorphic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Geist, David R

    2005-04-30

    This investigation, completed for the Pacific Northwest National Laboratory (PNNL), is part of the Grays River Watershed and Biological Assessment commissioned by Bonneville Power Administration under project number 2003-013-00 to assess impacts on salmon habitat in the upper Grays River watershed and present recommendations for habitat improvement. This report presents the findings of the geomorphic assessment and is intended to support the overall PNNL project by evaluating the following: The effects of historical and current land use practices on erosion and sedimentation within the channel network The ways in which these effects have influenced the sediment budget of the upper watershed The resulting responses in the main stem Grays River upstream of State Highway 4 The past and future implications for salmon habitat.

  4. Pavlovian conditioning and cumulative reinforcement rate.

    Science.gov (United States)

    Harris, Justin A; Patterson, Angela E; Gharaei, Saba

    2015-04-01

    In 5 experiments using delay conditioning of magazine approach with rats, reinforcement rate was varied either by manipulating the mean interval between onset of the conditioned stimulus (CS) and unconditioned stimulus (US) or by manipulating the proportion of CS presentations that ended with the US (trial-based reinforcement rate). Both manipulations influenced the acquisition of responding. In each experiment, a specific comparison was made between 2 CSs that differed in their mean CS-US interval and in their trial-based reinforcement rate, such that the cumulative reinforcement rate-the cumulative duration of the CS between reinforcements-was the same for the 2 CSs. For example, a CS reinforced on 100% of trials with a mean CS-US interval of 60 s was compared with a CS reinforced on 33% of trials and a mean duration of 20 s. Across the 5 experiments, conditioning was virtually identical for the 2 CSs with matched cumulative reinforcement rate. This was true as long as the timing of the US was unpredictable and, thus, response rates were uniform across the length of the CS. We conclude that the effects of CS-US interval and of trial-based reinforcement rate are reducible entirely to their common effect on cumulative reinforcement rate. We discuss the implications of this for rate-based, trial-based, and real-time associative models of conditioning.

  5. Future scenarios of urbanization and its effects on water quantity and quality in three New England watersheds

    Science.gov (United States)

    Hutyra, L.; Yang, Y.; Kim, J.; Cheng, C.; O'Brien, P.; Rouhani, S.; Douglas, E. M.; Nicolson, C.; Ryan, R.; Schaaf, C.; Warren, P.; Wollheim, W. M.

    2013-12-01

    New England watersheds have been impacted by human development and environmental stressors that are similar to those projected to impact large portions of the United States and the world. These impacts are likely to continue as some parts of the region are projected to lose over 60% of private forestland to development by 2030. Such dramatic changes have important consequences for water quality and quantity. Because of the complex and varied interactions between human and natural systems, simply understanding the processes affecting current and historical conditions in urbanizing watersheds is inadequate to model the future. Understanding future hydrologic conditions is made more difficult because of the uncertainties inherent in projecting future climate conditions. One approach to handling this complexity is to use scenarios to explore a range of potential futures following contrasting trajectories of change. Here we describe how four scenarios of land use change were developed using a stakeholder driven process. We then began using the scenarios in hydrological models to estimate future changes in water quality and quantity. The study area includes three watersheds (the Charles, Neponset and Ipswich) that have undergone varying degrees of urbanization in the greater Boston area of Massachusetts in the northeastern United States. The Charles and Neponset River watersheds are densely populated and include the city of Boston itself. Municipal water supplies in these two watersheds are mostly from the Massachusetts Water Resources Authority (MWRA) sources in western Massachusetts. The Ipswich River watershed is highly suburban, and communities are largely dependent on local water supplies. If the historical urbanization trends continue, the impervious area in the Charles River watershed is projected to increase by 13%, 16% in Neponset River watershed, and 24% in Ipswich River watershed by 2030. For the Charles River watershed, analyses identified hot spots for

  6. Effect of antiplatelet/anticoagulant therapy on severe ischemic complications in patients with giant cell arteritis: a cumulative meta-analysis.

    Science.gov (United States)

    Martínez-Taboada, Víctor Manuel; López-Hoyos, Marcos; Narvaez, Javier; Muñoz-Cacho, Pedro

    2014-08-01

    To evaluate the effect of antiplatelet/anticoagulant therapy on the occurrence of severe ischemic complications in GCA patients at diagnosis and while on treatment with corticosteroids (CS), and the risk of bleeding in these patients. A comprehensive search of PubMed and the Cochrane Central Register of Controlled Trials databases was completed and supplemented by hand searching of the references of all selected articles published from 1992 through December 2012. The cumulative meta-analysis included 6 retrospective studies that provided a total of 914 GCA patients. The effect of established antiplatelet/anticoagulant therapy on the occurrence of severe ischemic complications in patients with GCA at diagnosis and on the development of new severe ischemic complications in patients with GCA after diagnosis and while on treatment with CS were evaluated; as well as the risk of bleeding in patients with GCA on concomitant treatment with CS and antiplatelet/anticoagulant therapy. Antiplatelet/anticoagulant therapy before the diagnosis of GCA was not associated with a protection to develop severe ischemic complications (OR: 0.661; 95% CI [0.287-1.520]; p=0.33). However, such a therapy may prevent from severe ischemic complications after the diagnosis of GCA (OR: 0.318; [0.101-0.996]; p=0.049) without increasing the risk of bleeding in patients with GCA on concomitant treatment with CS (OR: 0.658; [0.089-4.856]; p=0.682). Antiplatelet/anticoagulant therapy prior to the diagnosis of GCA was not associated with reduction in severe ischemic complications. However, antiplatelet/anticoagulant therapy demonstrated a marginal benefit when used together with CS therapy in patients with established GCA without associated bleeding risk. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Reduced peripheral expression of the glucocorticoid receptor α isoform in individuals with posttraumatic stress disorder: a cumulative effect of trauma burden.

    Directory of Open Access Journals (Sweden)

    Hannah Gola

    Full Text Available BACKGROUND: Posttraumatic stress disorder (PTSD is a serious psychiatric condition that was found to be associated with altered functioning of the hypothalamic-pituitary-adrenal (HPA axis and changes in glucocorticoid (GC responsiveness. The physiological actions of GCs are primarily mediated through GC receptors (GR of which isoforms with different biological activities exist. This study aimed to investigate whether trauma-experience and/or PTSD are associated with altered expression of GR splice variants. METHODS: GRα and GRβ mRNA expression levels were determined by real-time quantitative PCR in whole blood samples of individuals with chronic and severe forms of PTSD (n = 42 as well as in ethnically matched reference subjects (non-PTSD, n = 35. RESULTS: Individuals suffering from PTSD exhibited significantly lower expression of the predominant and functionally active GRα isoform compared to non-PTSD subjects. This effect remained significant when accounting for gender, smoking, psychotropic medication or comorbid depression. Moreover, the GRα expression level was significantly negatively correlated with the number of traumatic event types experienced, both in the whole sample and within the PTSD patient group. Expression of the less abundant and non-ligand binding GRβ isoform was comparable between patient and reference groups. CONCLUSIONS: Reduced expression of the functionally active GRα isoform in peripheral blood cells of individuals with PTSD seems to be a cumulative effect of trauma burden rather than a specific feature of PTSD since non-PTSD subjects with high trauma load showed an intermediate phenotype between PTSD patients and individuals with no or few traumatic experiences.

  8. Comparing effects of lake- and watershed-scale influences on communities of aquatic invertebrates in shallow lakes.

    Directory of Open Access Journals (Sweden)

    Mark A Hanson

    Full Text Available Constraints on lake communities are complex and are usually studied by using limited combinations of variables derived from measurements within or adjacent to study waters. While informative, results often provide limited insight about magnitude of simultaneous influences operating at multiple scales, such as lake- vs. watershed-scale. To formulate comparisons of such contrasting influences, we explored factors controlling the abundance of predominant aquatic invertebrates in 75 shallow lakes in western Minnesota, USA. Using robust regression techniques, we modeled relative abundance of Amphipoda, small and large cladocera, Corixidae, aquatic Diptera, and an aggregate taxon that combined Ephemeroptera-Trichoptera-Odonata (ETO in response to lake- and watershed-scale characteristics. Predictor variables included fish and submerged plant abundance, linear distance to the nearest wetland or lake, watershed size, and proportion of the watershed in agricultural production. Among-lake variability in invertebrate abundance was more often explained by lake-scale predictors than by variables based on watershed characteristics. For example, we identified significant associations between fish presence and community type and abundance of small and large cladocera, Amphipoda, Diptera, and ETO. Abundance of Amphipoda, Diptera, and Corixidae were also positively correlated with submerged plant abundance. We observed no associations between lake-watershed variables and abundance of our invertebrate taxa. Broadly, our results seem to indicate preeminence of lake-level influences on aquatic invertebrates in shallow lakes, but historical land-use legacies may mask important relationships.

  9. Payments for watershed services: opportunities and realities

    Energy Technology Data Exchange (ETDEWEB)

    Bond, Ivan

    2007-08-15

    Many nations have found that regulatory approaches to land and water management have limited impact. An alternative is to create incentives for sound management - under mechanisms known as payments for ecosystem services. It is a simple idea: people who look after ecosystems that benefit others should be recognised and rewarded. In the case of watersheds, downstream beneficiaries of wise upstream land and water use should compensate the stewards. To be effective these 'payments for watershed services' must cover the cost of watershed management. In developing countries, they might also aid local development and reduce poverty. But new research shows that the problems in watersheds are complex and not easily solved. Payments for watershed services do not guarantee poverty reduction and cannot replace the best aspects of regulation.

  10. Measuring environmental sustainability of water in watersheds.

    Science.gov (United States)

    Hester, Erich T; Little, John C

    2013-08-06

    Environmental sustainability assessment is a rapidly growing field where measures of sustainability are used within an assessment framework to evaluate and compare alternative actions. Here we argue for the importance of evaluating environmental sustainability of water at the watershed scale. We review existing frameworks in brief before reviewing watershed-relevant measures in more detail. While existing measures are diverse, overlapping, and interdependent, certain attributes that are important for watersheds are poorly represented, including spatial explicitness and the effect of natural watershed components, such as rivers. Most studies focus on one or a few measures, but a complete assessment will require use of many existing measures, as well as, perhaps, new ones. Increased awareness of the broad dimensions of environmental sustainability as applied to water management should encourage integration of existing approaches into a unified assessment framework appropriate for watersheds.

  11. Regionalization of SWAT Model Parameters for Use in Ungauged Watersheds

    Directory of Open Access Journals (Sweden)

    Indrajeet Chaubey

    2010-11-01

    Full Text Available There has been a steady shift towards modeling and model-based approaches as primary methods of assessing watershed response to hydrologic inputs and land management, and of quantifying watershed-wide best management practice (BMP effectiveness. Watershed models often require some degree of calibration and validation to achieve adequate watershed and therefore BMP representation. This is, however, only possible for gauged watersheds. There are many watersheds for which there are very little or no monitoring data available, thus the question as to whether it would be possible to extend and/or generalize model parameters obtained through calibration of gauged watersheds to ungauged watersheds within the same region. This study explored the possibility of developing regionalized model parameter sets for use in ungauged watersheds. The study evaluated two regionalization methods: global averaging, and regression-based parameters, on the SWAT model using data from priority watersheds in Arkansas. Resulting parameters were tested and model performance determined on three gauged watersheds. Nash-Sutcliffe efficiencies (NS for stream flow obtained using regression-based parameters (0.53–0.83 compared well with corresponding values obtained through model calibration (0.45–0.90. Model performance obtained using global averaged parameter values was also generally acceptable (0.4 ≤ NS ≤ 0.75. Results from this study indicate that regionalized parameter sets for the SWAT model can be obtained and used for making satisfactory hydrologic response predictions in ungauged watersheds.

  12. Cumulative geoecological effects of 62 years of infrastructure and climate change in ice-rich permafrost landscapes, Prudhoe Bay Oilfield, Alaska.

    Science.gov (United States)

    Raynolds, Martha K; Walker, Donald A; Ambrosius, Kenneth J; Brown, Jerry; Everett, Kaye R; Kanevskiy, Mikhail; Kofinas, Gary P; Romanovsky, Vladimir E; Shur, Yuri; Webber, Patrick J

    2014-04-01

    Many areas of the Arctic are simultaneously affected by rapid climate change and rapid industrial development. These areas are likely to increase in number and size as sea ice melts and abundant Arctic natural resources become more accessible. Documenting the changes that have already occurred is essential to inform management approaches to minimize the impacts of future activities. Here, we determine the cumulative geoecological effects of 62 years (1949-2011) of infrastructure- and climate-related changes in the Prudhoe Bay Oilfield, the oldest and most extensive industrial complex in the Arctic, and an area with extensive ice-rich permafrost that is extraordinarily sensitive to climate change. We demonstrate that thermokarst has recently affected broad areas of the entire region, and that a sudden increase in the area affected began shortly after 1990 corresponding to a rapid rise in regional summer air temperatures and related permafrost temperatures. We also present a conceptual model that describes how infrastructure-related factors, including road dust and roadside flooding are contributing to more extensive thermokarst in areas adjacent to roads and gravel pads. We mapped the historical infrastructure changes for the Alaska North Slope oilfields for 10 dates from the initial oil discovery in 1968-2011. By 2010, over 34% of the intensively mapped area was affected by oil development. In addition, between 1990 and 2001, coincident with strong atmospheric warming during the 1990s, 19% of the remaining natural landscapes (excluding areas covered by infrastructure, lakes and river floodplains) exhibited expansion of thermokarst features resulting in more abundant small ponds, greater microrelief, more active lakeshore erosion and increased landscape and habitat heterogeneity. This transition to a new geoecological regime will have impacts to wildlife habitat, local residents and industry.

  13. Impact of water stress and nutrition on Vitis vinifera cv. ‘Albariño’: Soil-plant water relationships, cumulative effects and productivity

    Energy Technology Data Exchange (ETDEWEB)

    Martínez, E.M.; Rey, B.J.; Fandiño, M.; Cancela, J.J.

    2016-11-01

    The objective of the present study is to apply different systems of fertigation (rainfed, R; surface drip irrigation, DI, and subsurface drip irrigation, SDI) in Vitis vinifera (L.) cv. ‘Albariño’ to evaluate the cumulative effect of water stress (water stress integral) on yield parameters and to establish the relationship between indices and production. The study was conducted over four years (2010-2013) in a commercial vineyard (Galicia, NW Spain). The volumetric soil water content (θ) (with TDR) and predawn (ψp), midday (ψm) and stem (ψstem) leaf-water potential were determined with a water activity meter during the growing stages (flowering-harvest) from 2010-2013. The number of clusters, their weight and yield/vine were determined at harvest. Must composition was studied to evaluate nutrition treatments. Ψp is presented as the best indicator of the water status of the plant, and the sole use of θ is not recommended as a reference. The soil-plant water status variables were strongly correlated, especially between foliar variables (0.91

  14. Urban Stormwater Temperature Surges: A Central US Watershed Study

    Directory of Open Access Journals (Sweden)

    Sean J. Zeiger

    2015-10-01

    Full Text Available Impacts of urban land use can include increased stormwater runoff temperature (Tw leading to receiving water quality impairment. There is therefore a need to target and mitigate sources of thermal pollution in urban areas. However, complex relationships between urban development, stormwater runoff and stream water heating processes are poorly understood. A nested-scale experimental watershed study design was used to investigate stormwater runoff temperature impacts to receiving waters in a representative mixed-use urbanizing watershed of the central US. Daily maximum Tw exceeded 35.0 °C (threshold for potential mortality of warm-water biota at an urban monitoring site for a total of five days during the study period (2011–2013. Sudden increases of more than 1.0 °C within a 15 min time interval of Tw following summer thunderstorms were significantly correlated (CI = 95%; p < 0.01 to cumulative percent urban land use (r2 = 0.98; n = 29. Differences in mean Tw between monitoring sites were significantly correlated (CI = 95%; p = 0.02 to urban land use practices, stream distance and increasing discharge. The effects of the 2012 Midwest USA drought and land use on Tw were also observed with maximum Tw 4.0 °C higher at an urban monitoring site relative to a rural site for 10.5 h. The current work provides quantitative evidence of acute increases in Tw related to urban land use. Results better inform land managers wishing to create management strategies designed to preserve suitable thermal stream habitats in urbanizing watersheds.

  15. Sediment delivery modeling in practice: Comparing the effects of watershed characteristics and data resolution across hydroclimatic regions.

    Science.gov (United States)

    Hamel, Perrine; Falinski, Kim; Sharp, Richard; Auerbach, Daniel A; Sánchez-Canales, María; Dennedy-Frank, P James

    2017-02-15

    Geospatial models are commonly used to quantify sediment contributions at the watershed scale. However, the sensitivity of these models to variation in hydrological and geomorphological features, in particular to land use and topography data, remains uncertain. Here, we assessed the performance of one such model, the InVEST sediment delivery model, for six sites comprising a total of 28 watersheds varying in area (6-13,500km(2)), climate (tropical, subtropical, mediterranean), topography, and land use/land cover. For each site, we compared uncalibrated and calibrated model predictions with observations and alternative models. We then performed correlation analyses between model outputs and watershed characteristics, followed by sensitivity analyses on the digital elevation model (DEM) resolution. Model performance varied across sites (overall r(2)=0.47), but estimates of the magnitude of specific sediment export were as or more accurate than global models. We found significant correlations between metrics of sediment delivery and watershed characteristics, including erosivity, suggesting that empirical relationships may ultimately be developed for ungauged watersheds. Model sensitivity to DEM resolution varied across and within sites, but did not correlate with other observed watershed variables. These results were corroborated by sensitivity analyses performed on synthetic watersheds ranging in mean slope and DEM resolution. Our study provides modelers using InVEST or similar geospatial sediment models with practical insights into model behavior and structural uncertainty: first, comparison of model predictions across regions is possible when environmental conditions differ significantly; second, local knowledge on the sediment budget is needed for calibration; and third, model outputs often show significant sensitivity to DEM resolution.

  16. Effects of environmental amenities and locational disamenities on home values in the Santa Cruz watershed: a hedonic analysis using census data

    Science.gov (United States)

    Arora, Gaurav; Frisvold, George; Norman, Laura

    2014-01-01

    For this study, we used the hedonic pricing method to measure the effects of natural amenities on home prices in the U.S-side of the Santa Cruz Watershed. We employed multivariate spatial regression techniques to estimate how difference factors affect median home values in 613 census block groups of the 2000 Census, accounting for spatial autocorrelation, spatial lags, and/or spatial heterogeneity in the data. Diagnostic tests suggest that failure to account for the hedonic model can be classified as (1) physical features of the housing stock, (2) neighborhood characteristics, and (3) environmental attributes. Census data was combined with GIS data for vegetation and land cover, land administration, measures of species richness and open space, and proximity to amenities and disamenities. Census block groups close to the US-Mexico border of airports/air bases were negative. Results suggest that policies to maintain biodiversity and open space provide economic benefits to homeowners, reflected in higher home values. Future research will quantify the marginal effects of regression explanatory variables on home values to assess their economic and policy significant. These marginal effects will be used as input indicators to discern potential economic impacts of various scenarios in the Santa Cruz Watershed Ecosystem Portfolio Model (SCWEPM). Future research will also expand this effort into the Mexican-portion of the watershed.

  17. Long-term effects of surface coal mining on ground-water levels and quality in two small watersheds in eastern Ohio

    Science.gov (United States)

    Cunningham, W.L.; Jones, R.L.

    1990-01-01

    Two small watersheds in eastern Ohio that were surface mined for coal and reclaimed were studied during 1986-89. Water-level and water-quality data were compared with similar data collected during previous investigations conducted during 1976-83 to determine long-term effects of surface mining on the hydrologic system. Before mining, the watersheds were characterized by sequences of flat-lying sedimentary rocks containing two major coal seams and underclays. An aquifer was present above each of the underclays. Surface mining removed the upper aquifer, stripped the coal seam, and replaced the sediment. This created a new upper aquifer with different hydraulic and chemical characteristics. Mining did not disturb the middle aquifer. A third, deeper aquifer in each watershed was not studied. Water levels were continuously recorded in one well in each aquifer. Other wells were measured every 2 months. Water levels in the upper aquifers reached hydraulic equilibrium from 2 to 5 years after mining ceased. Water levels in the middle aquifers increased more than 5 feet during mining and reached equilibrium almost immediately thereafter. Water samples were collected from three upper-aquifer well, a seep from the upper aquifer, and the stream in each watershed. Two samples were collected in 1986 and 1987, and one each in 1988 and 1989. In both watersheds, sulfate replaced bicarbonate as the dominant upper-aquifer and surface-water anion after mining. For the upper aquifer of a watershed located in Muskingum County, water-quality data were grouped into premining and late postmining time periods (1986-89). The premining median pH and concentration of dissolved solids and sulfate were 7.6, 378 mg/L (milligrams per liter), and 41 mg/L, respectively. The premining median concentrations of iron and manganese were 10? /L (micrograms per liter) and 25?, respectively. The postmining median values of pH, dissolved solids, and sulfate were 6.7, 1,150 mg/L, and 560 mg/L, respectively

  18. Watershed Boundaries - Watershed Boundary Database for Montana

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This data set is a complete digital hydrologic unit boundary layer of the Subbasins (8-digit), Watersheds (10-digit), and Subwatersheds (12-digit) for Montana. This...

  19. Watershed Education for Broadcast Meteorologists

    Science.gov (United States)

    Lamos, J. P.; Sliter, D.; Espinoza, S.; Spangler, T. C.

    2006-12-01

    The National Environmental Education and Training Organization (NEETF) published a report in 2005 that summarized the findings of ten years of NEETF and Roper Research. The report stated, "Our years of data from Roper surveys show a persistent pattern of environmental ignorance even among the most educated and influential members of society." Market research has also shown that 80% of television viewers list the weather as the primary reason for watching the local news. Broadcast meteorologists, with a broader understanding of environmental and related sciences have an opportunity to use their weathercasts to inform the public about the environment and the factors that influence environmental health. As "station scientists," broadcast meteorologists can use the weather, and people's connection to it, to broaden their understanding of the environment they live in. Weather and watershed conditions associated with flooding and drought have major human and environmental impacts. Increasing the awareness of the general public about basic aspects of the hydrologic landscape can be an important part of mitigating the adverse effects of too much or too little precipitation, and of protecting the environment as well. The concept of a watershed as a person's natural neighborhood is a very important one for understanding hydrologic and environmental issues. Everyone lives in a watershed, and the health of a watershed is the result of the interplay between weather and human activity. This paper describes an online course to give broadcast meteorologists a basic understanding of watersheds and how watersheds are impacted by weather. It discusses how to convey watershed science to a media- savvy audience as well as how to model the communication of watershed and hydrologic concepts to the public. The course uses a narrative, story-like style to present its content. It is organized into six short units of instruction, each approximately 20 minutes in duration. Each unit is

  20. Effects of highway construction on stream water quality and macroinvertebrate condition in a Mid-Atlantic Highlands watershed, USA

    Science.gov (United States)

    Chen, Y.; Viadero, R.C.; Wei, X.; Fortney, Ronald H.; Hedrick, Lara B.; Welsh, S.A.; Anderson, James T.; Lin, L.-S.

    2009-01-01

    Refining best management practices (BMPs) for future highway construction depends on a comprehensive understanding of environmental impacts from current construction methods. Based on a before-after-control impact (BACI) experimental design, long-term stream monitoring (1997-2006) was conducted at upstream (as control, n = 3) and downstream (as impact, n = 6) sites in the Lost River watershed of the Mid-Atlantic Highlands region, West Virginia. Monitoring data were analyzed to assess impacts of during and after highway construction on 15 water quality parameters and macroinvertebrate condition using the West Virginia stream condition index (WVSCI). Principal components analysis (PCA) identified regional primary water quality variances, and paired t tests and time series analysis detected seven highway construction-impacted water quality parameters which were mainly associated with the second principal component. In particular, impacts on turbidity, total suspended solids, and total iron during construction, impacts on chloride and sulfate during and after construction, and impacts on acidity and nitrate after construction were observed at the downstream sites. The construction had statistically significant impacts on macroinvertebrate index scores (i.e., WVSCI) after construction, but did not change the overall good biological condition. Implementing BMPs that address those construction-impacted water quality parameters can be an effective mitigation strategy for future highway construction in this highlands region. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  1. Watershed responses to Amazon soya bean cropland expansion and intensification.

    Science.gov (United States)

    Neill, Christopher; Coe, Michael T; Riskin, Shelby H; Krusche, Alex V; Elsenbeer, Helmut; Macedo, Marcia N; McHorney, Richard; Lefebvre, Paul; Davidson, Eric A; Scheffler, Raphael; Figueira, Adelaine Michela e Silva; Porder, Stephen; Deegan, Linda A

    2013-06-05

    The expansion and intensification of soya bean agriculture in southeastern Amazonia can alter watershed hydrology and biogeochemistry by changing the land cover, water balance and nutrient inputs. Several new insights on the responses of watershed hydrology and biogeochemistry to deforestation in Mato Grosso have emerged from recent intensive field campaigns in this region. Because of reduced evapotranspiration, total water export increases threefold to fourfold in soya bean watersheds compared with forest. However, the deep and highly permeable soils on the broad plateaus on which much of the soya bean cultivation has expanded buffer small soya bean watersheds against increased stormflows. Concentrations of nitrate and phosphate do not differ between forest or soya bean watersheds because fixation of phosphorus fertilizer by iron and aluminium oxides and anion exchange of nitrate in deep soils restrict nutrient movement. Despite resistance to biogeochemical change, streams in soya bean watersheds have higher temperatures caused by impoundments and reduction of bordering riparian forest. In larger rivers, increased water flow, current velocities and sediment flux following deforestation can reshape stream morphology, suggesting that cumulative impacts of deforestation in small watersheds will occur at larger scales.

  2. Southern Watersheds Common Reedgrass Monitoring Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Southern Watersheds Common Reedgrass Project is an interagency effort to increase public awareness of the common reedgrass problem, demonstrate effective control...

  3. Carbon exchange in Western Siberian watershed mires and implication for the greenhouse effect. A spatial temporal modeling approach

    Energy Technology Data Exchange (ETDEWEB)

    Borren, W.

    2007-01-19

    The vast watershed mires of Western Siberia formed a significant sink of carbon during the Holocene. Because of their large area these mires might play an important role in the carbon exchange between terrestrial ecosystems and the atmosphere. However, estimation of the Holocene and future carbon balance of whole Western Siberian mires is hampered by the lack of spatially resolved models. The main objective was to assess the carbon exchange fluxes of the mires using a 3-D dynamic approach. These exchange fluxes comprise the sequestration of carbon dioxide (CO2) by peat growth, the emission of methane (CH4) by anaerobic peat decay and the emission of CO2 by aerobic peat decay. From the detailed analysis of peat cores from different sites in the southern taiga of Western Siberia, it emerged that Holocene peat growth and carbon accumulation had different trends, caused by variations in vegetation succession. These differences were strongly influenced by the position in the landscape. Therefore, the effect of climatic change on mire development varied spatially. The indirect effects of climate change through local hydrology appeared to be more important than direct influences of changes in precipitation and temperature. Mire development is closely connected to hydrological dynamics. In the thesis a 3-D dynamic modeling approach is described that makes use of groundwater modeling. In successive timesteps peat growth and decay as well as mire type distribution were calculated, depending on hydrological conditions. The model was forced with a paleo-precipitation record to include variable climatic input. The model results show the Holocene development of a watershed mire from a few small spots to a contiguous mire landscape. As hydrology is the major limiting factor, the mire development is most sensitive to precipitation and evapotranspiration. Under unchanged conditions the mire will grow further, eventually reaching its maximum peat thickness around 11400 yr A.D. Under

  4. A new family of cumulative indexes for measuring scientific performance.

    Directory of Open Access Journals (Sweden)

    Marcin Kozak

    Full Text Available In this paper we propose a new family of cumulative indexes for measuring scientific performance which can be applied to many metrics, including h index and its variants (here we apply it to the h index, h(2 index and Google Scholar's i10 index. These indexes follow the general principle of repeating the index calculation for the same publication set. Using bibliometric data and reviewer scores for accepted and rejected fellowship applicants we examine how valid the cumulative variant is compared to the original variant. These analyses showed that the cumulative indexes result in higher correlations with the reviewer scores than their original variants. Thus, the cumulative indexes better reflect the assessments by peers than the original variants and are useful extensions of the original indexes. In contrast to many other measures of scientific performance proposed up to now, the cumulative indexes seem not only to be effective, but they are also easy to understand and calculate.

  5. Estimating the effects of potential climate and land use changes on hydrologic processes of a large agriculture dominated watershed

    Science.gov (United States)

    Neupane, Ram P.; Kumar, Sandeep

    2015-10-01

    Land use and climate are two major components that directly influence catchment hydrologic processes, and therefore better understanding of their effects is crucial for future land use planning and water resources management. We applied Soil and Water Assessment Tool (SWAT) to assess the effects of potential land use change and climate variability on hydrologic processes of large agriculture dominated Big Sioux River (BSR) watershed located in North Central region of USA. Future climate change scenarios were simulated using average output of temperature and precipitation data derived from Special Report on Emission Scenarios (SRES) (B1, A1B, and A2) for end-21st century. Land use change was modeled spatially based on historic long-term pattern of agricultural transformation in the basin, and included the expansion of corn (Zea mays L.) cultivation by 2, 5, and 10%. We estimated higher surface runoff in all land use scenarios with maximum increase of 4% while expanding 10% corn cultivation in the basin. Annual stream discharge was estimated higher with maximum increase of 72% in SRES-B1 attributed from higher groundwater contribution of 152% in the same scenario. We assessed increased precipitation during spring season but the summer precipitation decreased substantially in all climate change scenarios. Similar to decreased summer precipitation, discharge of the BSR also decreased potentially affecting agricultural production due to reduced future water availability during crop growing season in the basin. However, combined effects of potential land use change with climate variability enhanced for higher annual discharge of the BSR. Therefore, these estimations can be crucial for implications of future land use planning and water resources management of the basin.

  6. Evaluating the effect of different vegetative filter strip designs on sediment movement in an agricultural watershed using LISEM, Iowa, USA

    Science.gov (United States)

    Luquin Oroz, Eduardo; Cruse, Rick; Baartman, Jantiene; Keesstra, Saskia

    2016-04-01

    Although restoration of native vegetation in vulnerable areas would decrease soil loss, this approach is not feasible in communities that base their income on agriculture. However, an alternative exists: strategically placing a small percentage of vegetative filter strips (VFS) within agriculture fields for erosion control. Factors influencing their effectiveness are shallow conditions, vegetation type, filter strip width, slope, soil type, and rainfall characteristics. Generally, the first few meters of the strip are where most sediments deposit. For slopes higher than 10%, effectiveness decreases with increasing slope gradient. Usually, high rainfall intensity and sediment load in overland flow decrease vegetative filter strips' effectiveness. Nowadays, Iowa (USA), experiences increasingly stronger rainstorms; climate change is expected to increase rainfall erosive forces between 16 to 58%. Thus, there is a need to obtain new insights about strip design and its influence on sediment dynamics. Therefore, the objective of this study is to analyze strip design (width) impact on soil and water movement. To do so, different strip widths (no strips, 1.5, 3, 5, 7.5 and 10 meters wide) were analyzed under four rainfall intensities (increments of 10, 25, 50 and 75%) The event-based, hydrological and soil erosion model LISEM was used to simulate different scenarios. The model has been calibrated with data from 3-ha 'Interim 1' watershed, which is part of Walnut Creek (Iowa, USA). During a single event with sediment load, on July 18th 2010, intensities reached up to 80 mm/h. Two different land covers exist: (i) perennial vegetation, which has prairie vegetation covering patches and strips; and (ii) row crop agriculture where corn and soybeans are the main two crops in the area. Based on the different combination of widths and intensities, 24 scenarios were generated. At the moment, the model is on the final part of the calibration; scenario results will be presented on the

  7. Avoiding Program-Induced Cumulative Overload (PICO).

    Science.gov (United States)

    Orr, Robin; Knapik, Joseph J; Pope, Rodney

    2016-01-01

    This article defines the concept of program-induced cumulative overload (PICO), provides examples, and advises ways to mitigate the adverse effects. PICO is the excessive cumulative physical workload that can be imparted to military personnel by a military training program with an embedded physical training component. PICO can be acute (accumulating within a single day) or chronic (accumulating across the entirety of the program) and results in adverse outcomes for affected personnel, including detrimental fatigue, performance degradation, injuries, or illness. Strategies to mitigate PICO include focusing administration and logistic practices during the development and ongoing management of a trainee program and implementing known musculoskeletal injury prevention strategies. More training is not always better, and trainers need to consider the total amount of physical activity that military personnel experience across both operational training and physical training if PICO is to be mitigated.

  8. An investigation of the effects of spatial heterogeneity of initial soil moisture content on surface runoff simulation at a small watershed scale

    Science.gov (United States)

    Morbidelli, Renato; Saltalippi, Carla; Flammini, Alessia; Corradini, Corrado; Brocca, Luca; Govindaraju, Rao S.

    2016-08-01

    In addition to the soil saturated hydraulic conductivity, Ks, the initial soil moisture content, θi, is the quantity commonly incorporated in rainfall infiltration models for simulation of surface runoff hydrographs. Previous studies on the effect of the spatial heterogeneity of initial soil water content in the generation of surface runoff were generally not conclusive, and provided no guidance on designing networks for soil moisture measurements. In this study, the role of the spatial variability of θi at the small watershed scale is examined through the use of a simulation model and measurements of θi. The model combines two existing components of infiltration and surface runoff to model the flow discharge at the watershed outlet. The observed values of soil moisture in three experimental plots are combined to determine seven different distributions of θi, each used to compute the hydrographs produced by four different rainfall patterns for two initial conditions classified as "dry" soil and "wet" soil. For rainfalls events typically associated with floods, the spatial variability of θi at the watershed scale does not cause significant variations in surface runoff for initially dry or wet soils. Furthermore, when the main objective is to represent flood events a single ground point measurement of θi in each area with the same land use may suffice to obtain adequate outflow hydrographs at the outlet.

  9. Assessing Impacts of Typhoons and the Chi-Chi Earthquake on Chenyulan Watershed Landscape Pattern in Central Taiwan Using Landscape Metrics

    Science.gov (United States)

    Lin, Yu-Pin; Chang, Tsun-Kuo; Wu, Chen-Fa; Chiang, Te-Chih; Lin, Shin-Hwei

    2006-07-01

    The Chi-Chi earthquake (ML = 7.3) occurred in the central part of Taiwan on September 21, 1999. After the earthquake, typhoons Xangsane and Toraji produced heavy rainfall that fell across the eastern and central parts of Taiwan on November 2000 and July 2001. This study uses remote sensing data, landscape metrics, multivariate statistical analysis, and spatial autocorrelation to assess how earthquake and typhoons affect landscape patterns. It addresses variations of the Chenyulan watershed in Nantou County, near the earthquake’s epicenter and crossed by Typhoon Toraji. The subsequent disturbances have gradually changed landscape of the Chenyulan watershed. Disturbances of various types, sizes, and intensities, following various tracks, have various effects on the landscape patterns and variations of the Chenyulan watershed. The landscape metrics that are obtained by multivariate statistical analyses showed that the disturbances produced variously fragmented patches, interspersed with other patches and isolated from patches of the same type across the entire Chenyulan watershed. The disturbances also affected the isolation, size, and shape-complexity of patches at the landscape and class levels. The disturbances at the class level more strongly affected spatial variations in the landscape as well as patterns of grasslands and bare land, than variations in the watershed farmland and forest. Moreover, the earthquake with high magnitude was a starter to create these landscape variations in space in the Chenyulan watershed. The cumulative impacts of the disturbances on the watershed landscape pattern had existed, especially landslides and grassland in the study area, but were not always evident in space and time in landscape and other class levels.

  10. The study of the cumulative effects of the application of urban sewage sludge on an eroded soil cultivated in the Algerian steppe

    Science.gov (United States)

    Boutmedjet, Ahmed; Boukkaya, Nassira; Houyou, zohra; Ouakid, Mohamed; Bielders, Charles

    2014-05-01

    Since the seventies, desertification is one of the major problems faced by the Mediterranean climate regions. These problems are inherent in the soil and climate characteristics of these regions, but their magnitude and acuity depend mainly on human activities. The process of desertification that affects more and more land is more pronounced as soil degradation, which accelerates constantly reduced resources farmland and pasture. Especially in areas bordering the Sahara, as the Algerian steppe, a real belt between the Sahara and the Algerian tell As part of the study of the cumulative effect of the application of urban sewage sludge on sandy soil and culture that is a cereal (barley), we had results that enabled us to identify some precepts,. The short-term effects studied in this experiment indicate that the amendment of the sewage sludge had a beneficial effect on the fertilizing qualities of the soil and therefore the performance of barley. To observations of Culture (barley), indicate that the best grain yield was obtained with D3 (28.76 quintals / ha) and D2 (33.91 quintals / ha). This is due to the effect of the sludge by the addition of required nutrients crop production. The lowest yield (24.11 quintals / ha) being obtained for the control (D0). It is the same for straw yield, with 47.5 quintals / ha in D2. The D3 treatment (30 t / ha) has previously presented the best results, but after 3 years we noticed that the best yields are obtained with D2 (10 t / ha). Except the pH and the rate of limestone that are related to changes in the characteristics of the site, there was an improvement in some physical and chemical properties of the soil. The contributions of sewage sludge amended greater quality soil biology D2 (number and effective species collected). Increasing the organic matter content (1.45%) and electrical conductivity (0.18 microseconds / cm) in the soil is only significant for the highest dose (30t/ha), although a tendency to enrichment in

  11. Theory and work methods for the cumulative effects of environmental geochemistry in the metallic deposit cluster%金属矿集区地球化学环境累积效应的理论与工作方法

    Institute of Scientific and Technical Information of China (English)

    赵元艺; 曾辉; 徐友宁; 路璐

    2014-01-01

    In this study, the concept of geochemical environmental cumulative effects of soil heavy metal pollution in the ore concen-tration area is proposed, and the influencing factors, types and research methods are systematically summarized based on consulting nu-merous papers concerning the cumulative environmental effect published both in China and abroad. The definition includes overall effects of comprehensive reactions between heavy metal elements which are harmful to the environment and the transference and pre-cipitation of these elements in the special environment before, during and after mining . The influencing factors of cumulative effects are composed of pre-mining ore scale, ore-bearing rock, ore texture and structure, geographical environment, hydrological condi-tions, weathering conditions and mining methods and techniques. The types of cumulative effects are classified into eight types, such as time-crowded and space crowded effects. The results obtained by the authors have a great reference and guiding significance for the study of geochemical environmental cumulative effect.%在参阅国内外有关环境累积效应文献的基础上,总结和提出了金属矿集区地球化学环境累积效应的概念、影响因素、类型和工作方法。将矿集区地球化学环境累积效应划分为时间拥挤、空间拥挤等8种类型,识别土壤环境重金属累积效应背景值的方法有对比法和地球化学基线法,累积效应的研究内容包括累积因子、累积速率等8个方面。研究成果对于开展矿山地质化学环境累积效应具有借鉴和指导意义。

  12. Preserved cumulative semantic interference despite amnesia

    Directory of Open Access Journals (Sweden)

    Gary Michael Oppenheim

    2015-05-01

    As predicted by Oppenheim et al’s (2010 implicit incremental learning account, WRP’s BCN RTs demonstrated strong (and significant repetition priming and semantic blocking effects (Figure 1. Similar to typical results from neurally intact undergraduates, WRP took longer to name pictures presented in semantically homogeneous blocks than in heterogeneous blocks, an effect that increased with each cycle. This result challenges accounts that ascribe cumulative semantic interference in this task to explicit memory mechanisms, instead suggesting that the effect has the sort of implicit learning bases that are typically spared in hippocampal amnesia.

  13. Wash effect of atmospheric trace metals wet deposition and its source characteristic in subtropical watershed in China.

    Science.gov (United States)

    Gao, Yang; Hao, Zhuo; Yang, Tiantian; He, Nianpeng; Tian, Jing; Wen, Xuefa

    2016-10-01

    In order to better understand air pollution in deve-loping regions, such as China, it is important to investigate the wet deposition behavior of atmospheric trace metals and its sources in the subtropical watershed. This paper studies the seasonal change of trace metal concentrations in precipitation and other potential sources in a typical subtropical watershed (Jiazhuhe watershed) located in the downstream of the Yangtze River of China. The results show that typical crustal elements (Al, Fe) and trace element (Zn) have high seasonal variation patterns and these elements have higher contents in precipitation as compared to other metals in Jiazhuhe watershed. In addition, there is no observed Pb in base flow in this study, and the concentration magnitudes of Al, Ba, Fe, Mn, Sr, and Zn in base flow are significantly higher than that of other metals. During different rainfall events, the dynamic export processes are also different for trace metals. The various trace metals dynamic export processes lead to an inconsistent mass first flush and a significant accumulative variance throughout the rainfall events. It is found that in this region, most of the trace metals in precipitation are from anthropogenic emission and marine aerosols brought by typhoon and monsoon.

  14. Prescribed burning effects on soil physical properties and soil water repellency in a steep chaparral watershed, southern California, USA

    Science.gov (United States)

    K.R. Hubbert; H.K. Preisler; P.M. Wohlgemuth; R.C. Graham; M.G. Narog

    2006-01-01

    Chaparral watersheds associated with Mediterranean-type climate are distributed over five regions of the world. Because brushland soils are often shallow with low water holding capacities, and are on slopes prone to erosion, disturbances such as fire can adversely affect their physical properties. Fire can also increase the spatial coverage of soil water repellency,...

  15. Carbon exchange in Western Siberian watershed mires and implication for the greenhouse effect : A spatial temporal modeling approach

    NARCIS (Netherlands)

    Borren, W.

    2007-01-01

    The vast watershed mires of Western Siberia formed a significant sink of carbon during the Holocene. Because of their large area these mires might play an important role in the carbon exchange between terrestrial ecosystems and the atmosphere. However, estimation of the Holocene and future carbon

  16. Expansive Soil Crack Depth under Cumulative Damage

    Directory of Open Access Journals (Sweden)

    Bei-xiao Shi

    2014-01-01

    Full Text Available The crack developing depth is a key problem to slope stability of the expansive soil and its project governance and the crack appears under the roles of dry-wet cycle and gradually develops. It is believed from the analysis that, because of its own cohesion, the expansive soil will have a certain amount of deformation under pulling stress but without cracks. The soil body will crack only when the deformation exceeds the ultimate tensile strain that causes cracks. And it is also believed that, due to the combined effect of various environmental factors, particularly changes of the internal water content, the inherent basic physical properties of expansive soil are weakened, and irreversible cumulative damages are eventually formed, resulting in the development of expansive soil cracks in depth. Starting from the perspective of volumetric strain that is caused by water loss, considering the influences of water loss rate and dry-wet cycle on crack developing depth, the crack developing depth calculation model which considers the water loss rate and the cumulative damages is established. Both the proposal of water loss rate and the application of cumulative damage theory to the expansive soil crack development problems try to avoid difficulties in matrix suction measurement, which will surely play a good role in promoting and improving the research of unsaturated expansive soil.

  17. Cumulant expansions for atmospheric flows

    CERN Document Server

    Ait-Chaalal, Farid; Meyer, Bettina; Marston, J B

    2015-01-01

    The equations governing atmospheric flows are nonlinear, and consequently the hierarchy of cumulant equations is not closed. But because atmospheric flows are inhomogeneous and anisotropic, the nonlinearity may manifests itself only weakly through interactions of mean fields with disturbances such as thermals or eddies. In such situations, truncations of the hierarchy of cumulant equations hold promise as a closure strategy. We review how truncations at second order can be used to model and elucidate the dynamics of turbulent atmospheric flows. Two examples are considered. First, we study the growth of a dry convective boundary layer, which is heated from below, leading to turbulent upward energy transport and growth of the boundary layer. We demonstrate that a quasilinear truncation of the equations of motion, in which interactions of disturbances among each other are neglected but interactions with mean fields are taken into account, can successfully capture the growth of the convective boundary layer. Seco...

  18. Electro-cumulation CNF project

    CERN Document Server

    Grishin, V G

    2000-01-01

    bound or free ion current within solid substances; non-plain symmetry; cumulation of the ion interaction. Experimental result: an Ice SuperPolarization. Cold nuclear fusion ? At http://www.shortway.to/to2084 . Keywords: ion, current, solid, symmetry, cumulation, cold nuclear fusion, polarization, depolarization, ionic conductor, superionic conductor, ice, crystal, strain, V-center, V-centre, doped crystal, interstitial impurity, intrinsic color center, high pressure technology, Bridgman, experiment, crowdion, dielectric, proton, layer, defect, lattice, dynamics, electromigration, mobility, muon catalysis, concentration, doping, dopant, conductivity, pycnonuclear reaction, permittivity, dielectric constant, point defects, interstitials, polarizability, imperfection, defect centers, glass, epitaxy, sodium hydroxide, metallic substrate, crystallization, point, tip, susceptibility, ferroelectric, ordering, force, correlation, collective, shift, distortion, coalescence, crowdions, electrolysis.

  19. Effects of antecedent rain history on particulate phosphorus loss from a small forested watershed of Japanese cypress ( Chamaecyparis obtusa)

    Science.gov (United States)

    Ide, Jun'ichiro; Haga, Hirokazu; Chiwa, Masaaki; Otsuki, Kyoichi

    2008-05-01

    SummaryThis study aimed to clarify the effects of antecedent rain history on particulate phosphorus (PP) loss in a small mountainous watershed covered primarily with a plantation forest of Japanese cypress (Chamaecyparis obtusa). We analyzed stream discharge and PP concentration at 15-60 min intervals during 24 h in eight rain events with different discharge levels. The PP concentration versus stream discharge (PPC-Q) relationships exhibited clockwise hysteresis loops for each of the eight events monitored. Discharge could explain changes in PP concentration on the falling but not rising limb of the hydrograph. On the rising limb, a positive relationship between the rate of changes in discharge (dQ/dt) and the PP load (dL/dt) was found for each event. This indicates that a large amount of PP is strongly pulsed at times of rapidly increased discharge. These results suggest that dQ/dt is the driving force behind PP supply and the primary control on the clockwise hysteresis loop of PPC-Q relationship. There was a strong negative correlation between the antecedent precipitation index and the slope of the dL/dt versus dQ/dt relationship. This shows that a rapid increase in PP load occurs even with slight increases in discharge as antecedent moisture conditions become drier. The soil water repellency and rapid runoff response following dry conditions support that soil desiccation increases the PP supply associated with soil erosion via overland flow. Therefore, we concluded that the antecedent rain history affects the mobility of PP via soil desiccation. The findings of this study will fill gaps in our understanding of temporal variations in released fine sediment and associated PP as reported in previous studies.

  20. Effect of cropland management and slope position on soil organic carbon pool at the North Appalachian Experimental Watersheds

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Yueli; Lal, Rattan; Owens, Lloyd; Izaurralde, R Cesar C.; Post, W M.; Hothem, Daniel

    2002-12-01

    Soil organic matter is strongly related to soil type, landscape morphology, and soil and crop management practices. Therefore, long-term (15-36-years) effects of six cropland management systems on soil organic carbon (SOC) pool in 0-30 cm depth were studied for the period of 1939-1999 at the North Appalachian Experimental Watersheds (<3 ha, Dystric Cambisol, Haplic Luvisol, and Haplic Alisol) near Coshocton, OH, USA. Six management treatments were: (1) no tillage continuous corn with NPK (NC); (2) no tillage continuous corn with NPK and manure (NTC-M); (3) no tillage corn?soybean rotation (NTR); (4) chisel tillage corn?soybean rotation (CTR); (5) moldboard tillage with corn?wheat?meadow?meadow rotation with improved practices (MTR-I); (6) moldboard tillage with corn?wheat?meadow?meadow rotation with prevalent practices (MTR-P). The SOC pool ranged from 24.5Mgha?1 in the 32-years moldboard tillage corn (Zea mays L.)?wheat (Triticum aestivum L.)?meadow?meadow rotation with straight row farming and annual application of fertilizer (N:P:K = 5:9:17) of 56?112 kg ha?1 and cattle (Bos taurus) manure of 9Mg ha?1 as the prevalent system (MTR-P) to 65.5Mgha?1 in the 36-years no tillage continuous corn with contour row farming and annual application of 170?225 kgNha?1 and appropriate amounts of P and K, and 6?11Mgha?1 of cattle manure as the improved system (NTC-M).

  1. Developing a Watershed Challenge

    Science.gov (United States)

    Roman, Harry T.

    2010-01-01

    This article presents a watershed challenge that gives students an opportunity to investigate the challenge of using a watershed area as a site for development, examining the many aspects of this multifaceted problem. This design challenge could work well in a team-based format, with students taking on specific aspects of the challenges and…

  2. Predicting Watershed Ecosystems Through Targeted Local Land Use Policies

    OpenAIRE

    2006-01-01

    Land-use change is arguably the most pervasive socioeconomic force driving the change and degradation of watershed ecosystems. This paper combines an econometric model of land use choice with three models of watershed health indicators (conventional water pollution, toxic water pollution, and the number of aquatic species at risk) to examine the effects of land use policies on watershed ecosystems through their effect on land use choice. The analysis is conducted using parcel-level data from ...

  3. Cumulative Paired φ-Entropy

    Directory of Open Access Journals (Sweden)

    Ingo Klein

    2016-07-01

    Full Text Available A new kind of entropy will be introduced which generalizes both the differential entropy and the cumulative (residual entropy. The generalization is twofold. First, we simultaneously define the entropy for cumulative distribution functions (cdfs and survivor functions (sfs, instead of defining it separately for densities, cdfs, or sfs. Secondly, we consider a general “entropy generating function” φ, the same way Burbea et al. (IEEE Trans. Inf. Theory 1982, 28, 489–495 and Liese et al. (Convex Statistical Distances; Teubner-Verlag, 1987 did in the context of φ-divergences. Combining the ideas of φ-entropy and cumulative entropy leads to the new “cumulative paired φ-entropy” ( C P E φ . This new entropy has already been discussed in at least four scientific disciplines, be it with certain modifications or simplifications. In the fuzzy set theory, for example, cumulative paired φ-entropies were defined for membership functions, whereas in uncertainty and reliability theories some variations of C P E φ were recently considered as measures of information. With a single exception, the discussions in the scientific disciplines appear to be held independently of each other. We consider C P E φ for continuous cdfs and show that C P E φ is rather a measure of dispersion than a measure of information. In the first place, this will be demonstrated by deriving an upper bound which is determined by the standard deviation and by solving the maximum entropy problem under the restriction of a fixed variance. Next, this paper specifically shows that C P E φ satisfies the axioms of a dispersion measure. The corresponding dispersion functional can easily be estimated by an L-estimator, containing all its known asymptotic properties. C P E φ is the basis for several related concepts like mutual φ-information, φ-correlation, and φ-regression, which generalize Gini correlation and Gini regression. In addition, linear rank tests for scale that

  4. Surface runoff scale effects in West African watersheds: Modeling and management options

    NARCIS (Netherlands)

    Giesen, van de N.C.; Stomph, T.J.; Ridder, de N.

    2005-01-01

    Measurements of surface runoff from uniform slopes of different lengths in West Africa have shown that longer slopes tend to have less runoff per unit of length than short slopes. The main reason for this scale effect is that once the rain stops, water on long slopes has more opportunity time to inf

  5. Monitoring the Effect of Wetland Conservation Practices in an Agricultural Watershed

    Science.gov (United States)

    Due to the substantial effect of agriculture on the extent and ability of wetlands to function, the U.S. Department of Agriculture (USDA) serves a key role in wetland conservation and restoration. The USDA has implemented several different conservation programs (e.g., the Wetland Reserve Program) wi...

  6. Effects of conservation practices on phosphorus loss reduction from an Indiana agricultural watershed

    Science.gov (United States)

    Phosphorus losses from agricultural lands have caused serious eutrophication problems, particularly in Lake Erie. However, techniques that can effectively reduce total and soluble phosphorus losses from croplands and drainage channels can be difficult to implement and gauge. This modeling study was ...

  7. A multifractal approach to characterize cumulative rainfall and tillage effects on soil surface micro-topography and to predict depression storage

    Directory of Open Access Journals (Sweden)

    E. Vidal Vázquez

    2010-10-01

    discriminate data sets with similar values for the vertical component of roughness. Conversely, both, rough and smooth soil surfaces, with high and low roughness values, respectively, can display similar levels of spectral complexity. Although in most of the studied cases trend removal produces increasing homogeneity in the spatial configuration of height readings, spectral complexity of individual data sets may increase or decrease, when slope or slope plus tillage tool marks are filtered. Increased cumulative rainfall had significant effects on various parameters from the generalized dimension, Dq, and singularity spectrum, f(α. Overall, micro-topography decay by rainfall was reflected on a shift of the singularity spectra, f(α from the left side (q>>0 to the right side (q<<0 and also on a shift of the generalized dimension spectra from the right side (q>>0 to the left side (q<<0. The use of an exponential model of vertical roughness indices, RR, and multifractal parameters accounting for the spatial configuration such as D1 or D5 improved estimation of water stored in surface depressions.

  8. A multifractal approach to characterize cumulative rainfall and tillage effects on soil surface micro-topography and to predict depression storage

    Directory of Open Access Journals (Sweden)

    E. Vidal Vázquez

    2010-03-01

    sets with similar values for the vertical component of roughness. Both, rough and smooth soil surfaces, with high and low roughness values, respectively, can display similar levels of spectral complexity. Although in most of the studied cases trend removal produces increasing homogeneity in the spatial configuration of height readings, spectral complexity of individual data sets may increase or decrease, when slope or slope plus tillage tool marks are filtered. Increased cumulative rainfall had significant effects on various parameters from the generalized dimension, Dq, and singularity spectrum, f(α. Overall, micro-topography decay by rainfall produced was reflected on a shift of the singularity spectra, f(α from the left side (q>>0 to the right side (q<<0 and also on a shift of the generalized dimension spectra from the right side (q>>0 to the left side (q<<0. The use of an exponential model of vertical roughness indices, RR, and multifractal parameters accounting for the spatial configuration such as D1, D5, and D10 improved estimation of water stored in surface depressions.

  9. Evaluating Cumulative Ecosystem Response to Restoration Projects in the Columbia River Estuary, Annual Report 2005

    Energy Technology Data Exchange (ETDEWEB)

    Diefenderfer, Heida L.; Thom, Ronald M.; Borde, Amy B.; Roegner, G. C.; Whiting, Allan H.; Johnson, Gary E.; Dawley, Earl; Skalski, John R.; Vavrinec, John; Ebberts, Blaine D.

    2006-12-20

    This report is the second annual report of a six-year project to evaluate the cumulative effects of habitat restoration projects in the Columbia River Estuary, conducted by Pacific Northwest National Laboratory's Marine Sciences Laboratory, NOAA's National Marine Fisheries Service Pt. Adams Biological Field Station, and the Columbia River Estuary Study Taskforce for the US Army Corps of Engineers. In 2005, baseline data were collected on two restoration sites and two associated reference sites in the Columbia River estuary. The sites represent two habitat types of the estuary--brackish marsh and freshwater swamp--that have sustained substantial losses in area and that may play important roles for salmonids. Baseline data collected included vegetation and elevation surveys, above and below-ground biomass, water depth and temperature, nutrient flux, fish species composition, and channel geometry. Following baseline data collection, three kinds of restoration actions for hydrological reconnection were implemented in several locations on the sites: tidegate replacements (2) at Vera Slough, near the city of Astoria in Oregon State, and culvert replacements (2) and dike breaches (3) at Kandoll Farm in the Grays River watershed in Washington State. Limited post-restoration data were collected: photo points, nutrient flux, water depth and temperature, and channel cross-sections. In subsequent work, this and additional post-restoration data will be used in conjunction with data from other sites to estimate net effects of hydrological reconnection restoration projects throughout the estuary. This project is establishing methods for evaluating the effectiveness of individual projects and a framework for assessing estuary-wide cumulative effects including a protocol manual for monitoring restoration and reference sites.

  10. Cumulative stress and autonomic dysregulation in a community sample.

    Science.gov (United States)

    Lampert, Rachel; Tuit, Keri; Hong, Kwang-Ik; Donovan, Theresa; Lee, Forrester; Sinha, Rajita

    2016-05-01

    Whether cumulative stress, including both chronic stress and adverse life events, is associated with decreased heart rate variability (HRV), a non-invasive measure of autonomic status which predicts poor cardiovascular outcomes, is unknown. Healthy community dwelling volunteers (N = 157, mean age 29 years) participated in the Cumulative Stress/Adversity Interview (CAI), a 140-item event interview measuring cumulative adversity including major life events, life trauma, recent life events and chronic stressors, and underwent 24-h ambulatory ECG monitoring. HRV was analyzed in the frequency domain and standard deviation of NN intervals (SDNN) calculated. Initial simple regression analyses revealed that total cumulative stress score, chronic stressors and cumulative adverse life events (CALE) were all inversely associated with ultra low-frequency (ULF), very low-frequency (VLF) and low-frequency (LF) power and SDNN (all p stress and chronic stress each was significantly associated with SDNN and ULF even after the highly significant contributions of age and sex, with no other covariates accounting for additional appreciable variance. For VLF and LF, both total cumulative stress and chronic stress significantly contributed to the variance alone but were not longer significant after adjusting for race and health behaviors. In summary, total cumulative stress, and its components of adverse life events and chronic stress were associated with decreased cardiac autonomic function as measured by HRV. Findings suggest one potential mechanism by which stress may exert adverse effects on mortality in healthy individuals. Primary preventive strategies including stress management may prove beneficial.

  11. Additive effects prevail: The response of biota to multiple stressors in an intensively monitored watershed.

    Science.gov (United States)

    Gieswein, Alexander; Hering, Daniel; Feld, Christian K

    2017-09-01

    Freshwater ecosystems are impacted by a range of stressors arising from diverse human-caused land and water uses. Identifying the relative importance of single stressors and understanding how multiple stressors interact and jointly affect biology is crucial for River Basin Management. This study addressed multiple human-induced stressors and their effects on the aquatic flora and fauna based on data from standard WFD monitoring schemes. For altogether 1095 sites within a mountainous catchment, we used 12 stressor variables covering three different stressor groups: riparian land use, physical habitat quality and nutrient enrichment. Twenty-one biological metrics calculated from taxa lists of three organism groups (fish, benthic invertebrates and aquatic macrophytes) served as response variables. Stressor and response variables were subjected to Boosted Regression Tree (BRT) analysis to identify stressor hierarchy and stressor interactions and subsequently to Generalised Linear Regression Modelling (GLM) to quantify the stressors standardised effect size. Our results show that riverine habitat degradation was the dominant stressor group for the river fauna, notably the bed physical habitat structure. Overall, the explained variation in benthic invertebrate metrics was higher than it was in fish and macrophyte metrics. In particular, general integrative (aggregate) metrics such as % Ephemeroptera, Plecoptera and Trichoptera (EPT) taxa performed better than ecological traits (e.g. % feeding types). Overall, additive stressor effects dominated, while significant and meaningful stressor interactions were generally rare and weak. We concluded that given the type of stressor and ecological response variables addressed in this study, river basin managers do not need to bother much about complex stressor interactions, but can focus on the prevailing stressors according to the hierarchy identified. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. A Multiple Watershed Approach to Assessing the Effects of Habitat Restoration Actions on Anadromous and Resident Fish Populations, Technical Report 2003-2004.

    Energy Technology Data Exchange (ETDEWEB)

    Marmorek, David

    2004-03-01

    Habitat protection and restoration is a cornerstone of current strategies to restore ecosystems, recover endangered fish species, and rebuild fish stocks within the Columbia River Basin. Strategies featuring habitat restoration include the 2000 Biological Opinion on operation of the Federal Columbia River Power System (FCRPS BiOp) developed by the National Marine Fisheries Service (NMFS), the 2000 Biological Opinion on Bull Trout developed by the US Fish and Wildlife Service (USFWS), and Sub-Basin Plans developed under the Fish and Wildlife Program of the Northwest Power and Conservation Council (NWPCC). There is however little quantitative information about the effectiveness of different habitat restoration techniques. Such information is crucial for helping scientists and program managers allocate limited funds towards the greatest benefits for fish populations. Therefore, it is critical to systematically test the hypotheses underlying habitat restoration actions for both anadromous and resident fish populations. This pilot project was developed through a proposal to the Innovative Projects fund of the NWPCC (ESSA 2002). It was funded by the Bonneville Power Administration (BPA) following reviews by the Independent Scientific Review Panel (ISRP 2002), the Columbia Basin Fish and Wildlife Authority (CBFWA 2002), the NWPCC and BPA. The study was designed to respond directly to the above described needs for information on the effectiveness of habitat restoration actions, including legal measures specified in the 2000 FCRPS BiOp (RPA 183, pg. 9-133, NMFS 2000). Due to the urgency of addressing these measures, the timeline of the project was accelerated from a duration of 18 months to 14 months. The purpose of this pilot project was to explore methods for evaluating past habitat restoration actions and their effects on fish populations. By doing so, the project will provide a foundation of retrospective analyses, on which to build prospective, multi-watershed designs

  13. A Multiple Watershed Approach to Assessing the Effects of Habitat Restoration Actions on Anadromous and Resident Fish Populations, Technical Report 2003-2004.

    Energy Technology Data Exchange (ETDEWEB)

    Marmorek, David

    2004-03-01

    Habitat protection and restoration is a cornerstone of current strategies to restore ecosystems, recover endangered fish species, and rebuild fish stocks within the Columbia River Basin. Strategies featuring habitat restoration include the 2000 Biological Opinion on operation of the Federal Columbia River Power System (FCRPS BiOp) developed by the National Marine Fisheries Service (NMFS), the 2000 Biological Opinion on Bull Trout developed by the US Fish and Wildlife Service (USFWS), and Sub-Basin Plans developed under the Fish and Wildlife Program of the Northwest Power and Conservation Council (NWPCC). There is however little quantitative information about the effectiveness of different habitat restoration techniques. Such information is crucial for helping scientists and program managers allocate limited funds towards the greatest benefits for fish populations. Therefore, it is critical to systematically test the hypotheses underlying habitat restoration actions for both anadromous and resident fish populations. This pilot project was developed through a proposal to the Innovative Projects fund of the NWPCC (ESSA 2002). It was funded by the Bonneville Power Administration (BPA) following reviews by the Independent Scientific Review Panel (ISRP 2002), the Columbia Basin Fish and Wildlife Authority (CBFWA 2002), the NWPCC and BPA. The study was designed to respond directly to the above described needs for information on the effectiveness of habitat restoration actions, including legal measures specified in the 2000 FCRPS BiOp (RPA 183, pg. 9-133, NMFS 2000). Due to the urgency of addressing these measures, the timeline of the project was accelerated from a duration of 18 months to 14 months. The purpose of this pilot project was to explore methods for evaluating past habitat restoration actions and their effects on fish populations. By doing so, the project will provide a foundation of retrospective analyses, on which to build prospective, multi-watershed designs

  14. The Algebra of the Cumulative Percent Operation.

    Science.gov (United States)

    Berry, Andrew J.

    2002-01-01

    Discusses how to help students avoid some pervasive reasoning errors in solving cumulative percent problems. Discusses the meaning of ."%+b%." the additive inverse of ."%." and other useful applications. Emphasizes the operational aspect of the cumulative percent concept. (KHR)

  15. Effects of Closing Mountain for Forest Restoration in the Watershed of Miyun Reservoir, Beijing

    Institute of Scientific and Technical Information of China (English)

    Yu Xinxiao; Niu Jianzhi; Xu Junliang

    2004-01-01

    The paper provides a systematical analysis of ecological restoration effects of natural secondary forest of closure area in Chao Guanxi Gou, Miyun County, Beijing. The results indicate that through more than twenty years of hillclosing afforestation since 1983, canopy closure has improved almost by 0.2; forest cover rate has raised from 7.2% to 93.8%; biodiversity, tree biomass and vegetation community have increased to a great extent. Compared with the average canopy closure before hillclosing afforestation in this area, it has improved to over 0.4 in average and increased by 0.1-0.2. The forest coverage degree has reached more than 90%. Consequently, the forest plays more important roles in intercepting precipitation, improving water storage capacity of soil, decreasing the surface runoff, and preventing soil and water loss.

  16. An Integrated Modeling Framework Forecasting Ecosystem Exposure-- A Systems Approach to the Cumulative Impacts of Multiple Stressors

    Science.gov (United States)

    Johnston, J. M.

    2013-12-01

    Freshwater habitats provide fishable, swimmable and drinkable resources and are a nexus of geophysical and biological processes. These processes in turn influence the persistence and sustainability of populations, communities and ecosystems. Climate change and landuse change encompass numerous stressors of potential exposure, including the introduction of toxic contaminants, invasive species, and disease in addition to physical drivers such as temperature and hydrologic regime. A systems approach that includes the scientific and technologic basis of assessing the health of ecosystems is needed to effectively protect human health and the environment. The Integrated Environmental Modeling Framework 'iemWatersheds' has been developed as a consistent and coherent means of forecasting the cumulative impact of co-occurring stressors. The Framework consists of three facilitating technologies: Data for Environmental Modeling (D4EM) that automates the collection and standardization of input data; the Framework for Risk Assessment of Multimedia Environmental Systems (FRAMES) that manages the flow of information between linked models; and the Supercomputer for Model Uncertainty and Sensitivity Evaluation (SuperMUSE) that provides post-processing and analysis of model outputs, including uncertainty and sensitivity analysis. Five models are linked within the Framework to provide multimedia simulation capabilities for hydrology and water quality processes: the Soil Water Assessment Tool (SWAT) predicts surface water and sediment runoff and associated contaminants; the Watershed Mercury Model (WMM) predicts mercury runoff and loading to streams; the Water quality Analysis and Simulation Program (WASP) predicts water quality within the stream channel; the Habitat Suitability Index (HSI) model scores physicochemical habitat quality for individual fish species; and the Bioaccumulation and Aquatic System Simulator (BASS) predicts fish growth, population dynamics and bioaccumulation

  17. Effects of cumulative stressful and acute variation episodes of farm climate conditions on late embryo/early fetal loss in high producing dairy cows

    Science.gov (United States)

    Santolaria, Pilar; López-Gatius, Fernando; García-Ispierto, Irina; Bech-Sàbat, Gregori; Angulo, Eduardo; Carretero, Teresa; Sánchez-Nadal, Jóse Antonio; Yániz, Jesus

    2010-01-01

    The aim of this study was to determine possible relationships between farm climate conditions, recorded from day 0 to day 40 post-artificial insemination (AI), and late embryo/early fetal loss in high producing dairy cows. Pregnancy was diagnosed by rectal ultrasonography between 28 and 34 days post-AI. Fetal loss was registered when a further 80- to 86-day diagnosis proved negative. Climate variables such as air temperature and relative humidity (RH) were monitored in the cubicles area for each 30-min period. Temperature-humidity indices (THI); cumulative stressful values and episodes of acute change (defined as the mean daily value 1.2 times higher or lower than the mean daily values of the 10 previous days) of the climate variables were calculated. The data were derived from 759 cows in one herd. A total of 692 pregnancies (91.2%) carried singletons and 67 (8.8%) carried twins. No triplets were recorded. Pregnancy loss was recorded in 6.7% (51/759) of pregnancies: 5.6% (39/692) in single and 17.9% (12/67) in twin pregnancies. Using logistic regression procedures, a one-unit increase in the daily cumulative number of hours for the THI values higher than 85 during days 11-20 of gestation caused a 1.57-fold increase in the pregnancy loss, whereas the likelihood of fetal loss increased by a factor of 1.16 for each additional episode of acute variation for the maximum THI values during gestation days 0-40. THI values higher than 85 and episodes of acute variation for the maximum THI values were only recorded during the warm and cool periods, respectively. The presence of twins led to a 3.98-fold increase in pregnancy loss. In conclusion, our findings show that cumulative stressful and episodes of acute variation of climatic conditions can compromise the success of gestation during both the cool and warm periods of the year. Twin pregnancy was confirmed as a main factor associated with pregnancy loss.

  18. Effects on watershed hydrology after rain forest conversion to shifting cultivation and agroforestry in Sabah, Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Fagerberg, Nils

    1998-12-31

    A paired catchment study was conducted in Mendolong, Sabah, Malaysia, to monitor the hydrological effects from conversion of secondary rain forest to shifting cultivation and agroforestry land-uses. Four different treatments were investigated: (1.) Agroforestry with initial burning and planting of fast-growing trees (Acacia mangium) and one rotation of hill rice, (2.) Agroforestry treatment as in no. 1, but without burning, (3.) Shifting cultivation with burning and one rotation of hill rice and (4.) No burning and one rotation of hill rice. A fifth catchment was used as untreated control. Waterflow was continuously measured in the streams during 41 months, between May 1994 to November 1997. 11 months were used as a calibration period before clear-felling and treatments. The data were used to determine water budgets (precipitation, runoff and evapotranspiration), runoff increases after clear-felling and changes in streamflow regimes. Regression analyses on runoff from each catchment versus the control catchment during the calibration period were used to determine the increase in runoff after clear-felling. Some unexpected losses and gains of water across the borders of the divided catchments were detected in three of the five catchments. The estimated transferred water volumes under forest cover range between 10 % and 22 % of total runoff. After clear-felling the losses and gains of water across the borders increased. The water transfer did mainly occur as sub-surface flow, probably in more permeable parts in the lower soil profile like cracks in the bedrock. Generally, the risk of deep leakage seams to increase with distance from the ridge. Hydrological effects could still be calculated through amalgamation of two of the catchments, and since the third catchment had a stable level of water gain due to unchanged conditions in the surrounding catchments. The mean areal rainfall during the period was higher than earlier measurements in the area, 4061 mm. The mean

  19. Effects on watershed hydrology after rainforest conversion to shifting cultivation and agroforestry in Sabah, Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Fagerberg, Nils

    1998-07-01

    A paired catchment study was conducted in Mendolong, Sabah, Malaysia, to monitor the hydrological effects from conversion of secondary rain forest to shifting cultivation and agroforestry land-uses. Four different treatments were investigated: (1.) Agroforestry with initial burning and planting of fast-growing trees (Acacia mangium) and one rotation of hill rice, (2.) Agroforestry treatment as in no. 1, but without burning, (3.) Shifting cultivation with burning and one rotation of hill rice and (4.) No burning and one rotation of hill rice. A fifth catchment was used as untreated control. Waterflow was continuously measured in the streams during 41 months, between May 1994 to November 1997. 11 months were used as a calibration period before clear-felling and treatments. The data were used to determine water budgets (precipitation, runoff and evapotranspiration), runoff increases after clear-felling and changes in streamflow regimes. Regression analyses on runoff from each catchment versus the control catchment during the calibration period were used to determine the increase in runoff after clear-felling. Some unexpected losses and gains of water across the borders of the divided catchments were detected in three of the five catchments. The estimated transferred water volumes under forest cover range between 10 % and 22 % of total runoff. After clear-felling the losses and gains of water across the borders increased. The water transfer did mainly occur as sub-surface flow, probably in more permeable parts in the lower soil profile like cracks in the bedrock. Generally, the risk of deep leakage seams to increase with distance from the ridge. Hydrological effects could still be calculated through amalgamation of two of the catchments, and since the third catchment had a stable level of water gain due to unchanged conditions in the surrounding catchments. The mean areal rainfall during the period was higher than earlier measurements in the area, 4061 mm. The mean

  20. Effects on watershed hydrology after rain forest conversion to shifting cultivation and agroforestry in Sabah, Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Fagerberg, Nils.

    1998-01-01

    A paired catchment study was conducted in Mendolong, Sabah, Malaysia, to monitor the hydrological effects from conversion of secondary rain forest to shifting cultivation and agroforestry land-uses. Four different treatments were investigated: (1.) Agroforestry with initial burning and planting of fast-growing trees (Acacia mangium) and one rotation of hill rice, (2.) Agroforestry treatment as in no. 1, but without burning, (3.) Shifting cultivation with burning and one rotation of hill rice and (4.) No burning and one rotation of hill rice. A fifth catchment was used as untreated control. Waterflow was continuously measured in the streams during 41 months, between May 1994 to November 1997. 11 months were used as a calibration period before clear-felling and treatments. The data were used to determine water budgets (precipitation, runoff and evapotranspiration), runoff increases after clear-felling and changes in streamflow regimes. Regression analyses on runoff from each catchment versus the control catchment during the calibration period were used to determine the increase in runoff after clear-felling. Some unexpected losses and gains of water across the borders of the divided catchments were detected in three of the five catchments. The estimated transferred water volumes under forest cover range between 10 % and 22 % of total runoff. After clear-felling the losses and gains of water across the borders increased. The water transfer did mainly occur as sub-surface flow, probably in more permeable parts in the lower soil profile like cracks in the bedrock. Generally, the risk of deep leakage seams to increase with distance from the ridge. Hydrological effects could still be calculated through amalgamation of two of the catchments, and since the third catchment had a stable level of water gain due to unchanged conditions in the surrounding catchments. The mean areal rainfall during the period was higher than earlier measurements in the area, 4061 mm. The mean

  1. Development of cost effective nutrient management strategies for a watershed with the DSS FyrisCOST

    Science.gov (United States)

    Collentine, D.; Johnsson, H.; Larsson, P.; Markensten, H.; Widén Nilsson, E.

    2012-12-01

    This paper describes an application of the FyrisCOST model to calculate the cost efficiency of alternative scenarios for nitrogen management in a small agricultural catchment in Southern Sweden. The scenarios include the spatial distribution by sub-catchment of a set of nitrogen abatement measures that have been identified as eligible for financial support under the Swedish Rural Development Program (wetlands, catch crops, spring plowing and a combination of these) with alternative crop distributions. The model FyrisCOST is a catchment scale DSS that has been developed for the evaluation of alternative nutrient mitigation strategies. This model is able to evaluate a range of mitigation approaches for phosphorous and nitrogen from several sources (point and diffuse). This allows cost efficiency to be estimated for a catchment based on a combination of measures. The model is currently being used to develop a data base for the Swedish Water Authorities on the cost efficiency of buffer zones for all small catchments in Sweden. Hydrological flows in the FyrisCOST model are built on the dynamic model FyrisNP and nutrient losses are derived from simulations from the Nutrient Leaching Coefficient Calculation System (NLeCCS) which includes the ICECREAMDB model for estimating phosphorus losses and the SOILNDB model for soil nitrogen leaching. FyrisCOST calculates nitrogen concentrations in effluent water for each sub-catchment. The concentration of nitrogen is dependent on the current land use and geographical conditions. In order to evaluate agricultural scenarios in FyrisCOST a method for calculating N leaching from agricultural land was constructed. The calculation includes crop rotations and tillage systems and differentiates between annual and perennial crops. The model is able to take into account the probability that a primary crop is followed by a specific crop/tillage system and the effect on nutrient losses estimated using a specially developed leaching

  2. A Resource Cost Aware Cumulative

    Science.gov (United States)

    Simonis, Helmut; Hadzic, Tarik

    We motivate and introduce an extension of the well-known cumulative constraint which deals with time and volume dependent cost of resources. Our research is primarily interested in scheduling problems under time and volume variable electricity costs, but the constraint equally applies to manpower scheduling when hourly rates differ over time and/or extra personnel incur higher hourly rates. We present a number of possible lower bounds on the cost, including a min-cost flow, different LP and MIP models, as well as greedy algorithms, and provide a theoretical and experimental comparison of the different methods.

  3. Effects of hydrology, watershed size, and agricultural practices on sediment yields in two river basins in Iowa and Mississippi

    Science.gov (United States)

    Merten, Gustavo Henrique; Welch, Heather L.; Tomer, M.D.

    2016-01-01

    The specific sediment yield (SSY) from watersheds is the result of the balance between natural, scale-dependent erosion and deposition processes, but can be greatly altered by human activities. In general, the SSY decreases along the course of a river as sediments are trapped in alluvial plains and other sinks. However, this relation between SSY and basin area can actually be an increasing one when there is a predominance of channel erosion relative to hillslope erosion. The US Geological Survey (USGS) conducted a study of suspended sediment in the Iowa River basin (IRB), Iowa, and the Yazoo River basin (YRB), Mississippi, from 2006 through 2008. Within each river basin, the SSY from four largely agricultural watersheds of various sizes (2.3 to 35,000 km2 [0.9 to 13,513 mi2]) was investigated. In the smallest watersheds, YRB sites had greater SSY compared to IRB sites due to higher rain erosivity, more erodible soils, more overland flow, and fluvial geomorphological differences. Watersheds in the YRB showed a steady decrease in SSY with increasing drainage basin area, whereas in the IRB, the maximum SSY occurred at the 30 to 500 km2 (11.6 to 193 mi2) scale. Subsurface tile drainage and limits to channel downcutting restrict the upstream migration of sediment sources in the IRB. Nevertheless, by comparing the SSY-basin size scaling relationships with estimated rates of field erosion under conservation and conventional tillage treatments reported in previous literature, we show evidence that the SSY-basin size relationship in both the IRB and YRB remain impacted by historical erosion rates that occurred prior to conservation efforts.

  4. Hydrologic modelling of the effect of snowmelt and temperature on a mountainous watershed

    Indian Academy of Sciences (India)

    Kwangmin Kang; Joo Hyoung Lee

    2014-06-01

    Snowmelt-runoff modelling in a mountainous basin is perceived as difficult due to the complexity of simulation. Theoretically, the snowmelt process should be influenced by temperature changes. It is still controversial as how to incorporate the temperature changes into the snowmelt-runoff model in a mountainous basin. This paper presents the results of a study in the North Fork American River basin where the snowmelt-runoff mechanism is modelled by relating the temperature changes to the elevation band in the basin. In this study, a distributed hydrologic model is used to explore the orographic effects on the snowmelt-runoff using the snowfall-snowmelt routine in Soil and Water Assessment Tool (SWAT). Three parameters, namely maximum snowmelt factor, minimum snowmelt factor, and snowpack temperature lag were analysed during the simulation. The model was validated using streamflow data from October 1, 1991 to September 30, 1994, with and without considering the elevation band. The result of this study suggests that the snowmelt-runoff model associated with the elevation band better represents the snowmelt-runoff mechanism in terms of Nash–Sutcliffe coefficient (NS), 2, and Root Mean Square Error (RMSE).

  5. Simulating the effect of climate change on stream temperature in the Trout Lake Watershed, Wisconsin

    Energy Technology Data Exchange (ETDEWEB)

    Selbig, William R., E-mail: wrselbig@usgs.gov

    2015-07-15

    The potential for increases in stream temperature across many spatial and temporal scales as a result of climate change can pose a difficult challenge for environmental managers, especially when addressing thermal requirements for sensitive aquatic species. This study evaluates simulated changes to the thermal regime of three northern Wisconsin streams in response to a projected changing climate using a modeling framework and considers implications of thermal stresses to the fish community. The Stream Network Temperature Model (SNTEMP) was used in combination with a coupled groundwater and surface water flow model to assess forecasts in climate from six global circulation models and three emission scenarios. Model results suggest that annual average stream temperature will steadily increase approximately 1.1 to 3.2 °C (varying by stream) by the year 2100 with differences in magnitude between emission scenarios. Daily mean stream temperature during the months of July and August, a period when cold-water fish communities are most sensitive, showed excursions from optimal temperatures with increased frequency compared to current conditions. Projections of daily mean stream temperature, in some cases, were no longer in the range necessary to sustain a cold water fishery. - Highlights: • A stream temperature model was calibrated for three streams in northern Wisconsin. • The effect of climate change on stream temperature was simulated in each stream. • Annual average stream temperature was projected to rise from 1 to 3 °C by 2100. • Forecasts of stream temperature exceeded optimal ranges for brook trout.

  6. Landscape processes, effects and the consequences of migration in their management at the Jatún Mayu watershed (Bolivia)

    Science.gov (United States)

    Penna, Ivanna; Jaquet, Stephanie; Sudmeier-Rieux, Karen; Kaenzig, Raoul; Schwilch, Gudrun; Jaboyedoff, Michel; Liniger, Hanspeter; Machaca, Angelica; Cuba, Edgar; Boillat, Sebastien

    2014-05-01

    Bolivia has a large rural population, mostly composed of subsistence farmers that face natural and anthropogenic driven processes affecting their livelihoods. In order to establish sustainable management strategies, it is important to understand the factors governing landscape changes. This work explores the geomorphic imprint and effects of natural and anthropogenic driven processes on three mountain communities undergoing de-population in the Jatún Mayu watershed (Cochabamba, Bolivia). Based on satellite image interpretation, field work and household surveys, we have identified gullies and landslides as main active processes, causing land losses, affecting inter-communal roads, etc. While landslides are mostly occurring in the middle and lower section of the basin, gullies are especially affecting the upper part (especially the southern slope). Our analysis indicated that in the middle and lower part of the basin, landslides are developing in response to the Jatún Mayu incision (slopes reach a critical angle and slope failures increase). However in the upper part, where no river down-cutting is taking place, preliminary analysis indicates that past and present human interventions (over-grazing, agriculture, road construction, etc.) play a key role on driving land degradation toward the formation of gullies. Based on the comparison of high resolution images from 2004 and 2009, we determined an agricultural land loss rate of 8452 m2/year, mostly in the form of landslides. One single event swept away 0.03 km2 of agricultural lands (~13 parcels), approximately 87% of an average household property. People's main concerns are hail, frost and droughts because they cause an "immediate" loss on family incomes, but the impacts caused by landslides and gullies are not disregarded by the communities and the government. Communities are organized to set up and maintain key infrastructure such as irrigation canals and roads. They also intend to develop protective measures

  7. Chinese Policies and Practices regarding Payments for Ecological Services in Watersheds

    Institute of Scientific and Technical Information of China (English)

    Liu Guihuan; Zhang Huiyuan; Wan Jun

    2008-01-01

    Watersheds provide a variety of ecological services including soil and water conservation,carbon sequestration and biodiversity protection.However,activities in a fast-growing economy significantly impact the supply and demand of these watershed services.To mitigate these impacts,the concept of payment for environmental and ecosystem services from watersheds has emerged in global academic and policy circles.The governments and academic communities in China have increasingly described payments for ecological services from watersheds with the concept of watershed eco-compensation as it is urgent to protect watershed ecosystems.Watershed eco-compensation has proved to be one of the most economically effective means of solving environmental problems of watersheds to be adopted by the Chinese government.This paper presents an objective analysis of the Chinese market for watershed ecosystem services,including supply and demand for the services.It also summarizes Chinese policies on watershed eco-compensation,including relevant laws and regulations and fiscal policies.In addition,it presents a review of Chinese practices in watershed eco-compensation,including the analysis of an ecological construction project in Westem China,inter-provincial watershed cco-compensation practices and plans,and payment for ecological services at the provincial and small watershed levels.Finally,it summarizes the key components of the process of payment in Chinese watershed eco-compensation.This discussion forms the basis of concluding suggestions for ecosystem services compensation and ecological protection in the large scale river basin.

  8. Watershed- and island wide-scale land cover changes in Puerto Rico (1930s-2004) and their potential effects on coral reef ecosystems.

    Science.gov (United States)

    Ramos-Scharrón, Carlos E; Torres-Pulliza, Damaris; Hernández-Delgado, Edwin A

    2015-02-15

    Anthropogenically enhanced delivery of sediments and other land-based sources of pollution represent well-recognized threats to nearshore coral reef communities worldwide. Land cover change is commonly used as a proxy to document human-induced alterations to sediment and pollutant delivery rates to coral reef bearing waters. In this article, land cover change was assessed for a 69-km(2) watershed in Puerto Rico between 1936 and 2004 by aerial photograph interpretation. Forests and sugar cane fields predominated from 1936 through the late 1970s, but while cropland dipped to negligible levels by 2004, net forest cover doubled and built-up areas increased tenfold. The watershed-scale land cover changes documented here mimicked those of the entire Puerto Rican landmass. Sediment yield predictions that rely on the sort of land cover changes reported here inevitably result in declining trends, but anecdotal and scientific evidence in the study watershed and throughout Puerto Rico suggests that sediment and pollutant loading rates still remain high and at potentially threatening levels. The simultaneous reduction in living coral cover that accompanied reforestation and urbanization patterns since the 1970s in our study region is discussed here within the context of the following non-mutually exclusive potential explanations: (a) the inability of land cover change-based assessments to discern spatially-focused, yet highly influential sources of sediment; (b) the potentially secondary role of cropland and forest cover changes in influencing nearshore coral reef conditions relative to other types of stressors like those related to climate change; and (c) the potentially dominant role that urban development may have had in altering marine water quality to the extent of reducing live coral cover. Since identification of the causes for coral reef degradation has proven elusive here and elsewhere, we infer that coral reef management may only be effective when numerous land- and

  9. Stormwater Impaired Watersheds

    Data.gov (United States)

    Vermont Center for Geographic Information — Stormwater impaired watersheds occuring on both the Priority Waters (Part D - Completed TMDL) and 303(d) list of waters (Part A - need TMDL) The Vermont State...

  10. Watershed Restoration Project

    Energy Technology Data Exchange (ETDEWEB)

    Julie Thompson; Betsy Macfarlan

    2007-09-27

    In 2003, the U.S. Department of Energy issued the Eastern Nevada Landscape Coalition (ENLC) funding to implement ecological restoration in Gleason Creek and Smith Valley Watersheds. This project was made possible by congressionally directed funding that was provided through the US Department of Energy, Energy Efficiency and Renewable Energy, Office of the Biomass Program. The Ely District Bureau of Land Management (Ely BLM) manages these watersheds and considers them priority areas within the Ely BLM district. These three entities collaborated to address the issues and concerns of Gleason Creek and Smith Valley and prepared a restoration plan to improve the watersheds’ ecological health and resiliency. The restoration process began with watershed-scale vegetation assessments and state and transition models to focus on restoration sites. Design and implementation of restoration treatments ensued and were completed in January 2007. This report describes the restoration process ENLC undertook from planning to implementation of two watersheds in semi-arid Eastern Nevada.

  11. Watershed Planning Basins

    Data.gov (United States)

    Vermont Center for Geographic Information — The Watershed Planning Basin layer is part of a larger dataset contains administrative boundaries for Vermont's Agency of Natural Resources. The dataset includes...

  12. 基于岩体爆破累积损伤效应的Hoek-Brown准则修正公式%Amended expressions of Hoek-Brown criterion based on blasting cumulative damage effects of rock mass

    Institute of Scientific and Technical Information of China (English)

    闫长斌; 李国权; 陈东亮; 刘振红; 刘建磊

    2011-01-01

    The disturbance and damage induced by excavation and blasting, especial blasting cumulative damage effects resulted from frequent blasting, will play down the integrity of rock mass, weaken the mechanical parameters of rock.mass and threaten the stability of rock engineering surely. Considered the blasting cumulative damage effects of rock mass, the shortages of Hoek-Brown criterion and its modified expressions were pointed out. The methods of obtaining the value of mb and s which could reflect the blasting cumulative damage effects, blasting disturbed state and the lowering degree of its mechanical parameters, were found by introducing integrity coefficient Kv and damage factor D. The cumulative expanded models of rock mass blasting damage were found with the baseline of rock mass sound velocity reducing ratio η and the models were used in the amended expressions of Hoek-Brown criterion, based on the relationship between sound velocity variation and blasting cumulative damage effects. The analysis of the amended expressions was carried out based on the simulative blasting tests in-situ and the data of sonic measurement. The research results show that the amended expressions of Hoek-Brown criterion taken blasting cumulative damage effects of rock mass into account are reasonable.%爆破开挖作业引起的扰动与损伤,特别是频繁爆破产生的累积损伤效应,必然导致岩体完整性降低,岩体力学参数弱化,从而威胁岩体工程稳定性.考虑岩体爆破损伤及其累积效应,指出了Hoek-Brown(赫克-布朗)准则及其改进公式的不足,引入完整性系数Kv和损伤因子D,建立了可以表征岩体爆破累积损伤效应、岩体爆破扰动状态及其力学参数弱化程度的mb和s的取值方法.基于声速变化与爆破累积损伤效应之间的联系,建立了以岩体声速降低率η为基准量的岩体爆破累积损伤扩展模型,并将该模型成功应用于提出的Hoek-Brown准则修正公式中.根据

  13. The cumulative effect of three decades of phosphogypsum amendments in reclaimed marsh soils from SW Spain: {sup 226}Ra, {sup 238}U and Cd contents in soils and tomato fruit

    Energy Technology Data Exchange (ETDEWEB)

    Abril, Jose-Maria [Dpto. Fisica Aplicada I, Universidad de Sevilla, EUITA, Ctra Utrera Km 1, 41013 Seville (Spain); Garcia-Tenorio, Rafael [Dpto. Fisica Aplicada II, Universidad de Sevilla, ETSA, Avda. Reina Mercedes s/n, 41012 Seville (Spain); Enamorado, Santiago M. [Dpto. Fisica Aplicada I, Universidad de Sevilla, EUITA, Ctra Utrera Km 1, 41013 Seville (Spain); Hurtado, M. Dolores; Andreu, Luis; Delgado, Antonio [Dpto. Ciencias Agroforestales, Universidad de Sevilla, EUITA, Ctra Utrera Km 1, 41013, Seville (Spain)

    2008-09-15

    Phosphogypsum (PG), a by-product of the phosphate fertiliser industries, has been applied as soil amendment to reduce Na saturation in soils, as in the reclaimed marsh area from SW Spain, where available PG has a typical fingerprint of 710 {+-} 40 Bq kg{sup -1} of {sup 226}Ra, 165 {+-} 15 Bq kg{sup -1} of {sup 238}U and 2.8 {+-} 0.4 mg kg{sup -1} of Cd. This work was focussed on the cumulative effects of PG amendments on the enrichment of these pollutants in cultivated soils and plants (Lycopersicum esculentum Mill L.) from the area studied, where PG has been applied since 1978 at recommended rates of 20-25 Mg ha{sup -1} every 2-3 years. A field experiment was conducted over three years to compare activity concentrations of {sup 226}Ra ({sup 214}Pb) and {sup 238}U ({sup 234}Th) in non-reclaimed soils, reclaimed soils with no additional PG application, and reclaimed soils with two additional PG applications. A non-significant effect of two PG amendments (in three years) was observed when compared with non-amended reclaimed plots. Nevertheless, a significant (p < 0.05) enrichment of {sup 226}Ra was observed in the surface horizon (0-30 cm) of reclaimed plots relative to deeper horizons and also when compared with the surface horizon of non-reclaimed soil (p < 0.05), thereby revealing the cumulative effect of three decades of PG applications. Furthermore, the effect of a continuous application of PG was studied by analysing soils and tomato fruits from six commercial farms with different cumulative rates of PG applied. Cadmium concentrations in tomatoes, which were one order of magnitude higher than those found in tomatoes from other areas in South Spain, were positively correlated (r = 0.917*) with {sup 226}Ra-concentration in soils, which can be considered an accurate index of the cumulative PG rate of each farm.

  14. The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation

    Science.gov (United States)

    Van Dongen, Hans P A.; Maislin, Greg; Mullington, Janet M.; Dinges, David F.

    2003-01-01

    OBJECTIVES: To inform the debate over whether human sleep can be chronically reduced without consequences, we conducted a dose-response chronic sleep restriction experiment in which waking neurobehavioral and sleep physiological functions were monitored and compared to those for total sleep deprivation. DESIGN: The chronic sleep restriction experiment involved randomization to one of three sleep doses (4 h, 6 h, or 8 h time in bed per night), which were maintained for 14 consecutive days. The total sleep deprivation experiment involved 3 nights without sleep (0 h time in bed). Each study also involved 3 baseline (pre-deprivation) days and 3 recovery days. SETTING: Both experiments were conducted under standardized laboratory conditions with continuous behavioral, physiological and medical monitoring. PARTICIPANTS: A total of n = 48 healthy adults (ages 21-38) participated in the experiments. INTERVENTIONS: Noctumal sleep periods were restricted to 8 h, 6 h or 4 h per day for 14 days, or to 0 h for 3 days. All other sleep was prohibited. RESULTS: Chronic restriction of sleep periods to 4 h or 6 h per night over 14 consecutive days resulted in significant cumulative, dose-dependent deficits in cognitive performance on all tasks. Subjective sleepiness ratings showed an acute response to sleep restriction but only small further increases on subsequent days, and did not significantly differentiate the 6 h and 4 h conditions. Polysomnographic variables and delta power in the non-REM sleep EEG-a putative marker of sleep homeostasis--displayed an acute response to sleep restriction with negligible further changes across the 14 restricted nights. Comparison of chronic sleep restriction to total sleep deprivation showed that the latter resulted in disproportionately large waking neurobehavioral and sleep delta power responses relative to how much sleep was lost. A statistical model revealed that, regardless of the mode of sleep deprivation, lapses in behavioral alertness

  15. Watershed Management Optimization Support Tool (WMOST) v2: User Manual and Case Studies

    Science.gov (United States)

    The Watershed Management Optimization Support Tool (WMOST) is a decision support tool that evaluates the relative cost-effectiveness of management practices at the local or watershed scale. WMOST models the environmental effects and costs of management decisions in a watershed c...

  16. Catchment legacies and time lags: a parsimonious watershed model to predict the effects of legacy storage on nitrogen export.

    Directory of Open Access Journals (Sweden)

    Kimberly J Van Meter

    Full Text Available Nutrient legacies in anthropogenic landscapes, accumulated over decades of fertilizer application, lead to time lags between implementation of conservation measures and improvements in water quality. Quantification of such time lags has remained difficult, however, due to an incomplete understanding of controls on nutrient depletion trajectories after changes in land-use or management practices. In this study, we have developed a parsimonious watershed model for quantifying catchment-scale time lags based on both soil nutrient accumulations (biogeochemical legacy and groundwater travel time distributions (hydrologic legacy. The model accurately predicted the time lags observed in an Iowa watershed that had undergone a 41% conversion of area from row crop to native prairie. We explored the time scales of change for stream nutrient concentrations as a function of both natural and anthropogenic controls, from topography to spatial patterns of land-use change. Our results demonstrate that the existence of biogeochemical nutrient legacies increases time lags beyond those due to hydrologic legacy alone. In addition, we show that the maximum concentration reduction benefits vary according to the spatial pattern of intervention, with preferential conversion of land parcels having the shortest catchment-scale travel times providing proportionally greater concentration reductions as well as faster response times. In contrast, a random pattern of conversion results in a 1:1 relationship between percent land conversion and percent concentration reduction, irrespective of denitrification rates within the landscape. Our modeling framework allows for the quantification of tradeoffs between costs associated with implementation of conservation measures and the time needed to see the desired concentration reductions, making it of great value to decision makers regarding optimal implementation of watershed conservation measures.

  17. Catchment legacies and time lags: a parsimonious watershed model to predict the effects of legacy storage on nitrogen export.

    Science.gov (United States)

    Van Meter, Kimberly J; Basu, Nandita B

    2015-01-01

    Nutrient legacies in anthropogenic landscapes, accumulated over decades of fertilizer application, lead to time lags between implementation of conservation measures and improvements in water quality. Quantification of such time lags has remained difficult, however, due to an incomplete understanding of controls on nutrient depletion trajectories after changes in land-use or management practices. In this study, we have developed a parsimonious watershed model for quantifying catchment-scale time lags based on both soil nutrient accumulations (biogeochemical legacy) and groundwater travel time distributions (hydrologic legacy). The model accurately predicted the time lags observed in an Iowa watershed that had undergone a 41% conversion of area from row crop to native prairie. We explored the time scales of change for stream nutrient concentrations as a function of both natural and anthropogenic controls, from topography to spatial patterns of land-use change. Our results demonstrate that the existence of biogeochemical nutrient legacies increases time lags beyond those due to hydrologic legacy alone. In addition, we show that the maximum concentration reduction benefits vary according to the spatial pattern of intervention, with preferential conversion of land parcels having the shortest catchment-scale travel times providing proportionally greater concentration reductions as well as faster response times. In contrast, a random pattern of conversion results in a 1:1 relationship between percent land conversion and percent concentration reduction, irrespective of denitrification rates within the landscape. Our modeling framework allows for the quantification of tradeoffs between costs associated with implementation of conservation measures and the time needed to see the desired concentration reductions, making it of great value to decision makers regarding optimal implementation of watershed conservation measures.

  18. Quantify Effects of Integrated Land Management on Water Quality in Agricultural Landscape in South Fork Watershed, Iowa River

    Science.gov (United States)

    Ha, M.; Wu, M. M.

    2014-12-01

    Sustainable biofuel feedstock production — environmental sustainability and economic sustainability — may be achieved by using a multi-faceted approach. This study focuses on quantifying the water sustainability of an integrated landscaping strategy, by which current land use and land management, cropping system, agricultural Best Management Practices (BMPs), and economics play equal roles. The strategy was applied to the South Fork watershed, IA, including the tributaries of Tipton and Beaver Creeks, which expand to 800-km2 drainage areas. The watershed is an agricultural dominant area covered with row-crops production. On the basis of profitability, switchgrass was chosen as a replacement for row crops in low-productivity land. Areas for harvesting agricultural residue were selected on the basis of soil conservation principals. Double cropping with a cover crop was established to further reduce soil loss. Vegetation buffer strips were in place at fields and in riparian areas for water quality control, resource conservation, and eco service improvement. The Soil and Water Assessment Tool (SWAT) was applied to evaluate source reduction under various management schemes and land use changes. SWAT modeling incorporated 10-yr meteorological information, soil data, land slope classification, land use, four-year crop-rotation cycle, and management operations. Tile drain and pothole parameters were modeled to assess the fate and transport of nutrients. The influence of landscape management and cropping systems on nitrogen and phosphorus loadings, erosion process, and hydrological performance at the sub-watershed scale was analyzed and key factors identified. Results suggest strongly that incorporating agricultural BMPs and conservation strategies into integrated landscape management for certain energy crops in row-crop production regions can be economical and environmentally sustainable.

  19. Influence of pretreatment systolic blood pressure on the effect of carvedilol in patients with severe chronic heart failure: the Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS) study.

    Science.gov (United States)

    Rouleau, Jean L; Roecker, Ellen B; Tendera, Michal; Mohacsi, Paul; Krum, Henry; Katus, Hugo A; Fowler, Michael B; Coats, Andrew J S; Castaigne, Alain; Scherhag, Armin; Holcslaw, Terry L; Packer, Milton

    2004-04-21

    We sought to evaluate the influence of pretreatment systolic blood pressure (SBP) on the efficacy and safety of carvedilol in patients with chronic heart failure (CHF). Although beta-blockers reduce the risk of death in CHF, there is little reported experience with these drugs in patients with a low pretreatment SBP, who may respond poorly to beta-blockade. We studied 2,289 patients with severe CHF who participated in the Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS) trial. Compared with placebo, carvedilol improved the clinical status and reduced the risk of death and the combined risk of death or hospitalization for any reason, for a cardiovascular reason, or for worsening heart failure (p 0.10). However, because patients with the lowest SBP were at highest risk of an event, they experienced the greatest absolute benefit from treatment with carvedilol. The lower the pretreatment SBP, the more likely that patients would report an adverse event, be intolerant of high doses of the study drug, or require permanent withdrawal of treatment (p < 0.001 for all). However, these risks were primarily related to the severity of the underlying illness and not to treatment with carvedilol. The current study provides little support for concerns about using beta-blockers (particularly those with vasodilatory actions) in patients with severe CHF who have a low SBP. Pretreatment blood pressure can identify patients who have the greatest need for risk reduction with carvedilol.

  20. Maintenance hemodialysis patients have high cumulative radiation exposure.

    LENUS (Irish Health Repository)

    Kinsella, Sinead M

    2010-10-01

    Hemodialysis is associated with an increased risk of neoplasms which may result, at least in part, from exposure to ionizing radiation associated with frequent radiographic procedures. In order to estimate the average radiation exposure of those on hemodialysis, we conducted a retrospective study of 100 patients in a university-based dialysis unit followed for a median of 3.4 years. The number and type of radiological procedures were obtained from a central radiology database, and the cumulative effective radiation dose was calculated using standardized, procedure-specific radiation levels. The median annual radiation dose was 6.9 millisieverts (mSv) per patient-year. However, 14 patients had an annual cumulative effective radiation dose over 20 mSv, the upper averaged annual limit for occupational exposure. The median total cumulative effective radiation dose per patient over the study period was 21.7 mSv, in which 13 patients had a total cumulative effective radiation dose over 75 mSv, a value reported to be associated with a 7% increased risk of cancer-related mortality. Two-thirds of the total cumulative effective radiation dose was due to CT scanning. The average radiation exposure was significantly associated with the cause of end-stage renal disease, history of ischemic heart disease, transplant waitlist status, number of in-patient hospital days over follow-up, and death during the study period. These results highlight the substantial exposure to ionizing radiation in hemodialysis patients.

  1. Use of a Cumulative Risk Scale to Predict Poor Intellectual and Academic Outcomes in Childhood Epilepsy.

    Science.gov (United States)

    Kavanaugh, Brian C; Scarborough, Vanessa Ramos; Salorio, Cynthia F

    2016-06-01

    Discrete risk factors for poor outcomes in childhood epilepsy have been identified, but it is unclear whether the combined effect of several risk factors better predicts outcome. The Epilepsy Cumulative Risk Scale was developed to quantify cumulative risk for poor outcomes in childhood epilepsy. Participants included 156 clinic-referred children with epilepsy. The Epilepsy Cumulative Risk Scale was developed using variables previously associated with functional outcomes. Scale utility was examined through its association with intellectual and academic functioning. All Epilepsy Cumulative Risk Scale variables were significantly associated with functioning. The Total Score (ie, cumulative effect) was most strongly correlated with cognition and academic skills. A Total Score ≥ 5 had the best sensitivity and specificity for differentiating those at high risk for poor outcomes. The Epilepsy Cumulative Risk Scale shows promise as a practical, data-driven tool for quantification of cumulative risk for poor outcomes in childhood epilepsy and may be helpful in detecting those needing referral for additional services.

  2. Cumulative Environmental Management Association : Wood Buffalo Region

    Energy Technology Data Exchange (ETDEWEB)

    Friesen, B. [Syncrude Canada Ltd., Edmonton, AB (Canada)

    2001-07-01

    The recently announced oil sands development of the Wood Buffalo Region in Alberta was the focus of this power point presentation. Both mining and in situ development is expected to total $26 billion and 2.6 million barrels per day of bitumen production. This paper described the economic, social and environmental challenges facing the resource development of this region. In addition to the proposed oil sands projects, this region will accommodate the needs of conventional oil and gas production, forestry, building of pipelines and power lines, municipal development, recreation, tourism, mining exploration and open cast mining. The Cumulative Environmental Management Association (CEMA) was inaugurated as a non-profit association in April 2000, and includes 41 members from all sectors. Its major role is to ensure a sustainable ecosystem and to avoid any cumulative impacts on wildlife. Other work underway includes the study of soil and plant species diversity, and the effects of air emissions on human health, wildlife and vegetation. The bioaccumulation of heavy metals and their impacts on surface water and fish is also under consideration to ensure the quality and quantity of surface water and ground water. 3 figs.

  3. Cumulative environmental management and the oil sands

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    In response to concerns regarding the cumulative environmental impacts of oil sands development within the Athabasca oil sands deposit, the government of Alberta established a Regional Sustainable Development Strategy (RSDS) to balance development with environmental protection. The environmental issues identified through the RSDS were addressed by the Cumulative Environmental Management Association (CEMA). CEMA's boundary is the Wood Buffalo region of northeastern Alberta. It identifies existing and future environmental effects in the region and proposes recommendations to regulatory bodies for reducing environmental impacts associated with oil sands development. This presentation outlined some of the 55 stakeholder representatives of CEMA, including Alberta government departments associated with resource development, oil sand developers within the region, and Aboriginal communities and First Nations. These stakeholders provide input on sector priorities and agree on environmental thresholds. Established working groups also address technical and scientific research issues identified in the RSDS such as sustainable ecosystems; surface waters; trace metals and air contaminants; nitrogen oxides and sulphur dioxides; and land reclamation. To date, CEMA has submitted more than 50 reports and has made 4 major environmental recommendations for trace metal management, ecosystem management tools, a framework for acid deposition management, and a landscape design checklist. tabs., figs.

  4. Higher Order Cumulants in Colorless Partonic Plasma

    CERN Document Server

    Cherif, S; Ladrem, M

    2016-01-01

    Any physical system considered to study the QCD deconfinement phase transition certainly has a finite volume, so the finite size effects are inevitably present. This renders the location of the phase transition and the determination of its order as an extremely difficult task, even in the simplest known cases. In order to identify and locate the colorless QCD deconfinement transition point in finite volume $T_{0}(V)$, a new approach based on the finite-size cumulant expansion of the order parameter and the $\\mathscr{L}_{m,n}$-Method is used.We have shown that both cumulants of higher order and their ratios, associated to the thermodynamical fluctuations of the order parameter, in QCD deconfinement phase transition behave in a particular enough way revealing pronounced oscillations in the transition region. The sign structure and the oscillatory behavior of these in the vicinity of the deconfinement phase transition point might be a sensitive probe and may allow one to elucidate their relation to the QCD phase...

  5. Innovativeness, population size and cumulative cultural evolution.

    Science.gov (United States)

    Kobayashi, Yutaka; Aoki, Kenichi

    2012-08-01

    Henrich [Henrich, J., 2004. Demography and cultural evolution: how adaptive cultural processes can produce maladaptive losses-the Tasmanian case. Am. Antiquity 69, 197-214] proposed a model designed to show that larger population size facilitates cumulative cultural evolution toward higher skill levels. In this model, each newborn attempts to imitate the most highly skilled individual of the parental generation by directly-biased social learning, but the skill level he/she acquires deviates probabilistically from that of the exemplar (cultural parent). The probability that the skill level of the imitator exceeds that of the exemplar can be regarded as the innovation rate. After reformulating Henrich's model rigorously, we introduce an overlapping-generations analog based on the Moran model and derive an approximate formula for the expected change per generation of the highest skill level in the population. For large population size, our overlapping-generations model predicts a much larger effect of population size than Henrich's discrete-generations model. We then investigate by way of Monte Carlo simulations the case where each newborn chooses as his/her exemplar the most highly skilled individual from among a limited number of acquaintances. When the number of acquaintances is small relative to the population size, we find that a change in the innovation rate contributes more than a proportional change in population size to the cumulative cultural evolution of skill level.

  6. Effects of nuclear potential on the cumulants of net-proton and net-baryon multiplicity distributions in Au+Au collisions at √{sNN} = 5GeV

    Science.gov (United States)

    He, Shu; Luo, Xiaofeng; Nara, Yasushi; Esumi, ShinIchi; Xu, Nu

    2016-11-01

    We analyze the rapidity and transverse momentum dependence for the cumulants of the net-proton and net-baryon distributions in Au+Au collisions at √{sNN} = 5GeV with a microscopic hadronic transport (JAM) model. To study the effects of mean field potential and softening of equation of state (EoS) on the fluctuations of net-proton (baryon) in heavy-ion collisions, the calculations are performed with two different modes. The softening of EoS is realized in the model by implementing the attractive orbit in the two-body scattering to introduce a reduction pressure of the system. By comparing the results from the two modes with the results from default cascade, we find the mean field potential and softening of EoS have strong impacts on the rapidity distributions (d N /d y) and the shape of the net-proton (baryon) multiplicity distributions. The net-proton (baryon) cumulants and their ratios calculated from all of the three modes are with similar trends and show significant suppression with respect to unity, which can be explained by the presence of baryon number conservations. It indicates that the effects of mean field potential and softening of EoS might be not the ingredients that are responsible to the observed strong enhancement in the most central Au+Au collisions at 7.7 GeV measured by the STAR experiment at RHIC.

  7. Realities of the Watershed Management Approach: The Magat Watershed Experience

    OpenAIRE

    Elazegui, Dulce D.; Combalicer, Edwin A.

    2004-01-01

    This paper aims to showcase the experience of the Magat watershed in the implementation of the watershed management approach. Magat watershed was declared as a forest-reservation area through Proclamation No. 573 on June 26, 1969 because of its great importance to human survival and environmental balance in the region. The Magat case demonstrates the important role that ‘champions’ like the local government unit (LGU) could play in managing the country’s watersheds. With the Nueva Viscaya pro...

  8. Hydrologic resilience of a Canadian Foothills watershed to forest harvest

    Science.gov (United States)

    Goodbrand, Amy; Anderson, Axel

    2016-04-01

    Recent investigations of long-term hydrometeorological, groundwater, and streamflow data from watersheds on the eastern slopes of the Canadian Rocky Mountains showed the streamflow regime was resilient to forest harvest. These watersheds had low levels of harvest relative to their size and a large area of sparsely vegetated alpine talus slopes and exposed bedrock; an area shown to generate the majority of runoff for streamflow. In contrast, watersheds located in the foothills of the Rocky Mountains are of lower relief and typically have harvestable timber throughout the watershed; therefore, these watersheds may be more sensitive to forest disturbance and have increased potential for streamflow response. This project assesses the hydrologic resilience of an Alberta Foothills watershed to forest harvest using a 23-year dataset from the Tri-Creeks Experimental Watershed (Tri-Creeks). Tri-Creeks has been the site of intensive streamflow, groundwater, snow accumulation, and precipitation observations from 1967 - 1990. During the early 1980s, forestry experiments were conducted to compare the effects of timber harvest and riparian buffers, and the effectiveness of timber harvesting ground rules in protecting fisheries and maintaining water resources within three sub-watersheds: Eunice (16.8 km2; control); Deerlick (15.2 km2; 36% streamside timber removal); and, Wampus (28.3 km2; 37% clear-cut). Statistical analyses were used to compare the pre-and post-harvest ratios of treatment to control sub-watershed runoff for: water year, monthly (April - October), snowmelt peak flow, and low flow (10th percentile streamflow) periods as an assessment of hydrologic resilience to forest harvest. The only significant post-harvest change was an increase in water yield during May at Wampus (Mann-Whitney (MW), pforest harvest. We hypothesize on the processes and characteristics that result in this watershed to exhibit greater resilience compared to other forested watersheds.

  9. Effects of Nuclear Potential on the Cumulants of Net-Proton and Net-Baryon Multiplicity Distributions in Au+Au Collisions at $\\sqrt{s_{\\text{NN}}} = 5\\,\\text{GeV}$

    CERN Document Server

    He, Shu; Nara, Yasushi; Esumi, ShinIchi; Xu, Nu

    2016-01-01

    We analyzed the rapidity and transverse momentum dependence for the cumulants of the net-proton and net-baryon distributions in Au+Au collisions at $\\sqrt{s_{\\text{NN}}} = 5\\,\\text{GeV}$ with a microscopic hadronic transport (JAM) model. To study the effects of mean field potential and softening of equation of state (EoS) on the fluctuations of net-proton (baryon) in heavy-ion collisions, the calculations are performed with two different modes. The softening of EoS is realized in the model by implementing the attractive orbit in the two-body scattering to introduce a reduction pressure of the system. By comparing the results from the two modes with the results from default cascade, we find the mean field potential and softening of EoS have strong impacts on the rapidity distributions ($\\text{d}N/\\text{d}y$) and the shape of the net-proton (baryon) multiplicity distributions. The net-proton (baryon) cumulants and their ratios calculated from all of the three modes are with similar trends and show significant s...

  10. The Effects of Changing Land Use and Climate on the Hydrology and Carbon Budget of Lake Simcoe Watershed, Ontario, Canada

    Science.gov (United States)

    Oni, Stephen Kayode

    The Lake Simcoe watershed (LSW) has experienced significant population growth and is under pressure from development. This has led to land use changes in the watershed in addition to the global climate change that is impacting every region of the world. In this thesis, remote sensing analysis, statistics and process-based modelling approaches were used to better understand dissolved organic carbon (DOC) and runoff dynamics in the changing landscape of LSW. The process-based approach involved the use of the HBV (Hydrologiska Byrans Vattenbalansavdelning) rainfall runoff model and the Integrated Catchment Model for Carbon (INCA-C). Statistical downscaling of the Canadian General Circulation Model (CGCM3) was used to predict the impact of climate change under the IPCC (Intergovernmental Panel on Climate Change) A1B and A2 scenarios. There was a significant land use change in LSW between 1994 and 2009 with a positive monotonic trend in runoff ratio across tributaries. Large increase in runoff ratio without corresponding increase in precipitation suggested that runoff drains more quickly over the land surfaces; an indication of increasing urban-induced impervious surfaces. However, there was a significant increase in air temperature (MK = 0.315; ppredicted an increase in air temperature by a maximum of 1.4°C by 2050 and up to 3.5°C by 2100 relative to the baseline period (1960-2000). HBV predicted a largest variability in the spring and winter season's runoff regimes (2020-2050) under both A1B and A2 scenarios. A 5% increase in DOC concentration and a 6% increase in flux were observed between period 1 (1994-1997) and period 2 (2007-2009). The observed increases were driven by spring (20%) and summer (26%). INCA-C predicted a positive monotonic increase in long-term DOC concentrations (2020-2100) in surface waters draining into Lake Simcoe under both scenarios with the largest seasonal variations in DOC concentrations predicted to occur in the summer months. This

  11. Life Cycle Assessment of Greenhouse Gas Emissions from Dairy Production in a Central New York State Watershed

    Science.gov (United States)

    Johnson, M. S.

    2009-12-01

    Cumulative greenhouse gas emissions related to dairy production in the Fall Creek watershed of central New York State were calculated using a life-cycle approach for the period 1975-2001. Expressed as CO2 equivalents (CO2e), emissions include CO2, CH4 and N2O related to fertilizer manufacture and transport, bovine metabolism, volatilization and leaching losses from applied fertilizer, nitrogen dynamics in crop residues, among a myriad of sources. During the 1975-2001 period, dairy N production in the study area increased by over 20%, although crop N production in the watershed declined by 33%. This change was driven by consolidation within the dairy industry that also led to a six-fold increase in N in feed imports into the watershed during the same period. Cumulative GHG emissions related to dairy production in Fall Creek rose by about 20% over 1975-2001 to about 14,000 tons CO2e per year for the 326 km2 watershed by 2001. In 1975, about 90% of CO2e emissions related to dairy production in the Fall Creek watershed were emitted within the watershed. However, by 2001 over 50% of emissions were generated outside of the watershed, primarily as N2O emissions related to fertilizer used in the production of feed subsequently imported into Fall Creek watershed.

  12. Biogeochemical legacy of prescribed fire in a giant sequoia-mixed conifer forest: A 16-year record of watershed balances

    Science.gov (United States)

    Engle, Diana L.; Sickman, James O.; Moore, Claudette M.; Esperanza, Annie M.; Melack, John M.; Keeley, Jon E.

    2008-03-01

    The effects of prescription burning on watershed balances of major ions in mixed conifer forest were examined in a 16-year paired catchment study in Sequoia National Park, California. The objective was to determine whether fire-related changes in watershed balances persist as long as estimated low-end natural fire-return intervals (≤10 years), and whether cumulative net export caused by fire could deplete nutrient stocks between successive fires. Inputs (wet + dry deposition) and outputs (stream export) of N, S, Cl-, HCO3-, Ca2+, Mg2+, Na+, K+, H+, and SiO2 were measured for 7 years preceding, and 9 years following, a prescribed burn of one of the catchments. After fire, runoff coefficients increased by 7% (in dry years) to 35% (in wet years). Inorganic N was elevated in stream water for 3 years after fire. Increased export of water, SO42-, Cl-, SiO2, and base cations continued through the end of the study. Pools and processes attributed to fire led to the cumulative loss, per hectare, of 1.2 kg N, 16 kg S, 25 kg Cl-, 130 kg Ca2+, 19 kg Mg2+, 71 kg Na+, 29 kg K+ and 192 kg Si, above that predicted by prefire regression equations relating export in the paired catchments. This additional export equaled <1% of the N, up to one-third of the Ca and Mg, and up to three-fourths of the K, contained in the forest floor prior to combustion. Changes in watershed balances indicated that low-end natural fire-return intervals may prevent complete reaccumulation of several elements between fires.

  13. Quantifying the Effect of Thinning Vegetation on Evapotranspiration in a Mountainous Watershed through Remote Sensing: Improving Water Balance Estimates for Managed Aquifer Recharge

    Science.gov (United States)

    Revelle, P.; Hendrickx, J. M. H.

    2015-12-01

    A long-term water balance study in an experimental watershed of the Sacramento Mountains in New Mexico monitors the impact of thinning vegetation on groundwater recharge. The study objective is to evaluate if thinning forest vegetation will increase groundwater recharge in the mountains to provide larger regional flows to aquifers in surrounding basins. In the semi-arid Southwest, evapotranspiration (ET) makes up 75 to 95% or more of the total water budget. The variability of daily vegetation transpiration and solar radiation with time of year and the effects of complex terrain create a seasonal and spatial variability of ET that is not well quantified in mountainous regions. Through applying the remote sensing model METRIC (Mapping Evapotranspiration with High Resolution and Internalized Calibration) to satellite imagery from the LANDSAT satellite, we calculate high-resolution maps of ET for the Sacramento Mountains watershed area to quantify spatially-distributed estimates of ET before and after thinning to provide improved estimates for determining the water balance and the effect on recharge. METRIC calculates ET through applying an energy balance spatially across an image to estimate ET for each pixel (30m x 30m). Differences in ET are calculated between thinned and control plots in the watershed before and after thinning with the net impact of thinning on ET for an image determined with standard statistical tests following a Before-After Control-Impact (BACI) approach commonly used in environmental impact assessment studies. Estimates of ET from METRIC indicate a net decrease in ET in the first year after thinning for all of the thinned plots but show significant variability (~2 - 12 %) between areas with different terrain characteristics. The impact of surface parameters such as slope, aspect, or albedo among others are currently being examined using multivariate statistical analysis methods to improve the understanding of the spatial and temporal

  14. Which mechanisms dominate the net effects of forest thinning on water yield and forest productivity in the semi-arid Santa Fe Municipal Watershed?

    Science.gov (United States)

    Dugger, A. L.; Tague, C.; Allen, C. D.; Ringler, T.

    2013-12-01

    It remains an open question whether, and under what conditions, forest thinning leads to water yield increases or decreases. Observations point in both directions, with clear examples of woody plant removal leading to increases, encroachment causing no change, and tree mortality resulting in both increases and decreases in downstream water yields. These seemingly conflicting results imply that different processes may dominate vegetation controls on catchment water yield, and that these dominant processes may vary with environment. While a framework has been proposed for hydrologic sensitivity to woody plant changes in grassland-woodland systems, these hypotheses have yet to be fully vetted in forested mountain catchments. To address this gap, we use a coupled ecologic-hydrologic modeling system (RHESSys) to examine different mechanisms through which thinning alters water partitioning: (1) increased (incoming) shortwave and decreased (canopy) longwave radiation, (2) decreased transpiration and increased surface evaporation, (3) decreased canopy and increased near-surface turbulent fluxes. Ultimately the net effect of forest thinning on water yield depends on the balance of these different mechanisms, and we seek to better understand how topographic, subsurface geophysical, and climatic conditions influence this balance. We focus on a semi-arid, forested, mountain watershed since these hydrologic systems are not only vital water supply sources for a large portion of the Southwest U.S., but also highly sensitive to changes in vegetation cover. We use an existing application of RHESSys in the Santa Fe (New Mexico) Municipal Watershed that has been validated against measurements of radiation, water, and carbon fluxes at nearby Ameriflux sites covering a range of conditions including undisturbed, thinned, and burned forest. We evaluate the effects of thinning on both downstream water yield and forest productivity across different site conditions (slope/aspect, soil water

  15. Aspect of cumulative fatigue damage under multiaxial strain cycling.

    Science.gov (United States)

    Zamrik, S. Y.; Tang, P. Y.

    1972-01-01

    The concept of order of loading and its effect on cumulative fatigue damage under multiaxial strain cyclings was investigated. The effect is illustrated through nonlinear relationships between biaxial fatigue damage and cycle-ratio diagrams. Uniaxial theories such as Miner's method, the convergence method, and the double linear damage rule in its special and generalized form, were examined and extended to the biaxial case through the octahedral shear strain theory. The generalized double linear damage rule was found more applicable to biaxial cumulative fatigue damage.

  16. [Cumulative trauma disorders: work or professional disease?].

    Science.gov (United States)

    de Carvalho, Marcus Vitor Diniz; Cavalcanti, Francisco Ivo Dantas; Soriano, Evelyne Pessoa; de Miranda, Hênio Ferreira

    2009-06-01

    This study aimed at reviewing the Brazilian legislation applied to occupational health. It refers to the diseases embodied in the Repetition Strain Injury (RSI) and Cumulative Trauma Disorders (CTD) regarded as work or professional diseases. This analysis allowed to perform the historical evolution of legislation concerning the issue, noting that the state of the art of regulation on RSI-CTD is anchored in specific regulation present in the Normative Instruction 98/2003, that establishes the diagnostic criteria and classification of RSI-CTD. It was concluded that according to the existing legislation in Brazil, the pathologies related to RSI-CTD are considered as work diseases and their legal effects are similar to the work-related accidents.

  17. Effects of forested floodplain soil properties on phosphorous concentrations in two Chesapeake Bay sub-watersheds, Virginia, USA.

    Science.gov (United States)

    Odhiambo, B K; Ricker, M C; Le Blanc, L M; Moxey, K A

    2016-08-01

    Aquatic ecosystems are known to undergo fluctuations in nutrient levels as a result of both natural and anthropogenic processes. Changes in both extrinsic and intrinsic fluvial dynamics necessitate constant monitoring as anthropogenic alterations exert new pressures to previously stable river basins. In this study, we analyzed stream water and riparian zone soil phosphorous (P) dynamics in two third-order sub-watersheds of the lower Chesapeake Bay in Virginia, USA. The Ni River is predominantly forested (70 % forested), and Sugarland Run is a more human impacted (>45 % impervious surfaces) sub-watershed located in the suburbs of Washington D.C. Total stream P concentrations were measured during both high and low flows and Mehlich-3 methods were used to evaluate potential P fluxes in riparian soils. The results show total stream P concentrations in Sugarland Run ranged from 0.002 to 0.20 ppm, with an average of 0.054 ppm. In contrast, the forested Ni River had typical stream P concentrations erosion rates and corresponding cut-bank P flux rates were estimated to be 7.98 cm year(-1) and 361 kg P year(-1) for Ni River and 9.84 cm year(-1) and 11,600 kg P year(-1) for Sugarland Run, respectively. The significantly higher values of total P in the stream water and floodplain cut-banks of Sugarland Run suggests erosion and resuspension of previously deposited legacy sediments is an important processes in this human-impacted basin.

  18. Cumulant dynamics in a finite population linkage equilibrium theory

    CERN Document Server

    Rattray, M; Rattray, Magnus; Shapiro, Jonathan L.

    1999-01-01

    The evolution of a finite population at linkage equilibrium is described in terms of the dynamics of phenotype distribution cumulants. This provides a powerful method for describing evolutionary transients and we elucidate the relationship between the cumulant dynamics and the diffusion approximation. A separation of time-scales between the first and higher cumulants for low mutation rates is demonstrated in the diffusion limit and provides a significant simplification of the dynamical system. However, the diffusion limit may not be appropriate for strong selection as the standard Fisher-Wright model of genetic drift can break down in this case. Two novel examples of this effect are considered: we shown that the dynamics may depend on the number of loci under strong directional selection and that environmental variance results in a reduced effective population size. We also consider a simple model of a changing environment which cannot be described by a diffusion equation and we derive the optimal mutation ra...

  19. Cumulate Fragments in Silicic Ignimbrites

    Science.gov (United States)

    Bachmann, O.; Ellis, B. S.; Wolff, J.

    2014-12-01

    Increasingly, studies are concluding that silicic ignimbrites are the result of the amalgamation of multiple discrete magma batches. Yet the existence of discrete batches presents a conundrum for magma generation and storage; if silicic magma batches are not generated nearly in situ in the upper crust, they must traverse, and reside within, a thermally hostile environment with large temperature gradients, resulting in low survivability in their shallow magmatic hearths. The Snake River Plain (Idaho, USA) is a type example of this 'multi-batch' assembly with ignimbrites containing multiple populations of pyroxene crystals, glass shards, and crystal aggregates. The ubiquitous crystal aggregates hint at a mechanism to facilitate the existence of multiple, relatively small batches of rhyolite in the upper crust. These aggregates contain the same plagioclase, pyroxene, and oxide mineral compositions as single phenocrysts of the same minerals in their host rocks, but they have significantly less silicic bulk compositions and lack quartz and sanidine, which occur as single phenocrysts in the deposits. This implies significant crystallization followed by melt extraction from mushy reservoir margins. The extracted melt then continues to evolve (crystallizing sanidine and quartz) while the melt-depleted margins provide an increasingly rigid and refractory network segregating the crystal-poor batches of magma. The hot, refractory, margins insulate the crystal-poor lenses, allowing (1) extended residence in the upper crust, and (2) preservation of chemical heterogeneities among batches. In contrast, systems that produce cumulates richer in low-temperature phases (quartz, K-feldspars, and/or biotite) favour remelting upon recharge, leading to less segregation of eruptible melt pockets and the formation of gradationally zoned ignimbrites. The occurrence of similar crystal aggregates from a variety of magmatic lineages suggests the generality of this process.

  20. Estimation of effective hydrologic properties of soils from observations of vegetation density. M.S. Thesis; [water balance of watersheds in Clinton, Maine and Santa Paula, California

    Science.gov (United States)

    Tellers, T. E.

    1980-01-01

    An existing one-dimensional model of the annual water balance is reviewed. Slight improvements are made in the method of calculating the bare soil component of evaporation, and in the way surface retention is handled. A natural selection hypothesis, which specifies the equilibrium vegetation density for a given, water limited, climate-soil system, is verified through comparisons with observed data and is employed in the annual water balance of watersheds in Clinton, Ma., and Santa Paula, Ca., to estimate effective areal average soil properties. Comparison of CDF's of annual basin yield derived using these soil properties with observed CDF's provides excellent verification of the soil-selection procedure. This method of parameterization of the land surface should be useful with present global circulation models, enabling them to account for both the non-linearity in the relationship between soil moisture flux and soil moisture concentration, and the variability of soil properties from place to place over the Earth's surface.

  1. Cumulative human impacts on marine predators

    DEFF Research Database (Denmark)

    Maxwell, Sara M; Hazen, Elliott L; Bograd, Steven J

    2013-01-01

    Stressors associated with human activities interact in complex ways to affect marine ecosystems, yet we lack spatially explicit assessments of cumulative impacts on ecologically and economically key components such as marine predators. Here we develop a metric of cumulative utilization and impact...

  2. The effect of fire on mercury cycling in the soils of forested watersheds: Acadia National Park, Maine, U.S.A

    Science.gov (United States)

    Amirbahman, A.; Ruck, P.L.; Fernandez, I.J.; Haines, T.A.; Kahl, J.S.

    2004-01-01

    This study compares mercury (Hg) and methylmercury (MeHg) distribution in the soils of two forested stream watersheds at Acadia National Park, Maine, U.S.A. Cadillac Brook watershed, which burned in 1947, has thin soils and predominantly deciduous vegetation. It was compared to the unburned Hadlock Brook watershed, with thicker soil and predominantly coniferous vegetation. Soils in both watersheds were primarily well drained. The fire had a significant impact on the Cadillac watershed, by raising the soil pH, altering the vegetation, and reducing carbon and Hg pools. Total Hg content was significantly higher (P history (e.g., fire) may be the determining factors for susceptibility to high Hg in biota. ?? 2004 Kluwer Academic Publisher. Printed in the Netherlands.

  3. Using Remotely Sensed Data and Watershed and Hydrodynamic Models to Evaluate the Effects of Land Cover Land Use Change on Aquatic Ecosystems in Mobile Bay, AL

    Science.gov (United States)

    Al-Hamdan, Mohammad; Estes, Maurice G., Jr.; Judd, Chaeli; Woodruff, Dana; Ellis, Jean; Quattrochi, Dale; Watson, Brian; Rodriquez, Hugo; Johnson, Hoyt

    2012-01-01

    Alabama coastal systems have been subjected to increasing pressure from a variety of activities including urban and rural development, shoreline modifications, industrial activities, and dredging of shipping and navigation channels. The impacts on coastal ecosystems are often observed through the use of indicator species. One such indicator species for aquatic ecosystem health is submerged aquatic vegetation (SAV). Watershed and hydrodynamic modeling has been performed to evaluate the impact of land cover land use (LCLU) change in the two counties surrounding Mobile Bay (Mobile and Baldwin) on SAV stressors and controlling factors (temperature, salinity, and sediment) in the Mobile Bay estuary. Watershed modeling using the Loading Simulation Package in C++ (LSPC) was performed for all watersheds contiguous to Mobile Bay for LCLU scenarios in 1948, 1992, 2001, and 2030. Remotely sensed Landsat-derived National Land Cover Data (NLCD) were used in the 1992 and 2001 simulations after having been reclassified to a common classification scheme. The Prescott Spatial Growth Model was used to project the 2030 LCLU scenario based on current trends. The LSPC model simulations provided output on changes in flow, temperature, and sediment for 22 discharge points into the estuary. These results were inputted in the Environmental Fluid Dynamics Computer Code (EFDC) hydrodynamic model to generate data on changes in temperature, salinity, and sediment on a grid throughout Mobile Bay and adjacent estuaries. The changes in the aquatic ecosystem were used to perform an ecological analysis to evaluate the impact on SAV habitat suitability. This is the key product benefiting the Mobile Bay coastal environmental managers that integrates the influences of temperature, salinity, and sediment due to LCLU driven flow changes with the restoration potential of SAVs. Data products and results are being integrated into NOAA s EcoWatch and Gulf of Mexico Data Atlas online systems for

  4. Towards Sustaining Water Resources and Aquatic Ecosystems: Forecasting Watershed Risks to Current and Future Land Use Change

    Science.gov (United States)

    Lohse, K. A.; Newburn, D.; Opperman, J. J.; Brooks, C.; Merenlender, A.

    2005-05-01

    Sustaining aquatic resources requires managing existing threats and anticipating future impacts. Resource managers and planners often have limited understanding of the relative effects of human activities on stream conditions and how these effects will change over time. Here we assess and forecast the relative impacts of land use on sediment concentrations in Mediterranean-climate watersheds in California. We focus on the Russian River basin, which supports threatened salmonid populations vulnerable to high levels of fine sediment. We ask the following questions: (1) What are the relative impacts of three different land uses (urban, exurban and agriculture) on the patterns of fine sediment in streams? (2) What is the relative contribution of past and current changes in land use activities on these patterns? and (3) What are the effects of future development on these sediment levels? First, we characterized land use at the parcel scale to calibrate the relative impacts of exurban and urban land use on stream substrate quality, characterized by the concentration of fine sediment surrounding spawning gravels (`embeddedness') in 105 stream reaches. Second, we built multiple ordinal logistic regression models on a subset of watersheds (n=64) and then evaluated substrate quality predictions against observed data from another set of watersheds (n=41). Finally, we coupled these models with spatially explicit land use change models to project future stream conditions and associated uncertainties under different development scenarios for the year 2010. We found that the percent of urban housing and agriculture were significant predictors of in-stream embeddedness. Model results from parcel-level land use data indicated that changes in development were better predictors of fine sediment than total development in a single time period. In addition, our results indicate that exurban development is an important threat to stream systems; increases in the percent of total exurban

  5. Latino Mothers' Cumulative Food Insecurity Exposure and Child Body Composition.

    Science.gov (United States)

    Hernandez, Daphne C

    2016-01-01

    To document whether an intergenerational transmission of food insecurity is occurring by assessing low-income foreign-born Latino mothers' experiences with food insecurity as none, once (either childhood or adulthood) or twice (during both childhood and adulthood). Also the association between maternal cumulative food insecurity and children's body composition was examined. Maternal self-reported surveys on retrospective measures of food insecurity during childhood, current measures of food insecurity, and demographics were collected from Houston-area community centers (N = 96). Children's body mass index (BMI) and waist circumference (WC) were directly assessed. Covariate-adjusted logistic regression models analyzed the association between cumulative food insecurity experiences and children's body composition. Fifty-eight percent of mothers experienced food insecurity both as a child and as an adult and 31% of the mothers experienced food insecurity either as a child or adult. Maternal cumulative exposure to food insecurity was unrelated to BMI but was negatively related to elevated WC. Although an intergenerational transmission of food insecurity does exist, maternal cumulative exposure to food insecurity does not impact children's body composition negatively in the short term. Studying the long-term effects of cumulative food insecurity exposure can provide information for the development and timing of obesity interventions.

  6. Designing for Watershed Inquiry

    Science.gov (United States)

    Bodzin, Alec; Shive, Louise

    2004-01-01

    In this article, we describe a collaborative design initiative with three secondary school teachers to promote the use of Web-based inquiry in the context of a watershed investigation. Design interviews that focus on instructional goals and pedagogical beliefs of classroom teachers were conducted. The interview protocol used a curricular framework…

  7. Watershed hydrology. Chapter 7.

    Science.gov (United States)

    Elons S. Verry; Kenneth N. Brooks; Dale S. Nichols; Dawn R. Ferris; Stephen D. Sebestyen

    2011-01-01

    Watershed hydrology is determined by the local climate, land use, and pathways of water flow. At the Marcell Experimental Forest (MEF), streamflow is dominated by spring runoff events driven by snowmelt and spring rains common to the strongly continental climate of northern Minnesota. Snowmelt and rainfall in early spring saturate both mineral and organic soils and...

  8. Fundamentals of watershed hydrology

    Science.gov (United States)

    Pamela J. Edwards; Karl W.J. Williard; Jon E. Schoonover

    2015-01-01

    This is a primer about hydrology, the science of water. Watersheds are the basic land unit for water resource management and their delineation, importance, and variation are explained and illustrated. The hydrologic cycle and its components (precipitation, evaporation, transpiration, soil water, groundwater, and streamflow) which collectively provide a foundation for...

  9. Allegheny County Watershed Boundaries

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset demarcates the 52 isolated sub-Watersheds of Allegheny County that drain to single point on the main stem rivers. Created by 3 Rivers 2nd Nature based...

  10. Analysis of sensory ratings data with cumulative link models

    DEFF Research Database (Denmark)

    Christensen, Rune Haubo Bojesen; Brockhoff, Per B.

    2013-01-01

    Examples of categorical rating scales include discrete preference, liking and hedonic rating scales. Data obtained on these scales are often analyzed with normal linear regression methods or with omnibus Pearson chi2 tests. In this paper we propose to use cumulative link models that allow...... for regression methods similar to linear models while respecting the categorical nature of the observations. We describe how cumulative link models are related to the omnibus chi2 tests and how they can lead to more powerful tests in the non-replicated setting. For replicated categorical ratings data we present...... a quasi-likelihood approach and a mixed effects approach both being extensions of cumulative link models. We contrast population-average and subject-specific interpretations based on these models and discuss how different approaches lead to different tests. In replicated settings, naive tests that ignore...

  11. Cumulative pion production via successive collisions in nuclear medium

    CERN Document Server

    Motornenko, A

    2016-01-01

    Production of pions in proton-nucleus (p+A) reactions outside of a kinematical boundary of proton-nucleon collisions, the so-called cumulative effect, is studied. The kinematical restrictions on pions emitted in backward direction in the target rest frame are analyzed. It is shown that cumulative pion production requires a presence of massive baryonic resonances that are produced during successive collisions of projectile with nuclear nucleons. After each successive collision the mass of created resonance may increase and, simultaneously, its longitudinal velocity decreases. Simulations within Ultra relativistic Quantum Molecular Dynamics model reveals that successive collisions of baryonic resonances with nuclear nucleons plays the dominant role in cumulative pion production in p+A reactions.

  12. Effects of land use, topography and socio-economic factors on river water quality in a mountainous watershed with intensive agricultural production in East china.

    Directory of Open Access Journals (Sweden)

    Jiabo Chen

    Full Text Available Understanding the primary effects of anthropogenic activities and natural factors on river water quality is important in the study and efficient management of water resources. In this study, analysis of Variance (ANOVA, Principal component analysis (PCA, Pearson correlations, Multiple regression analysis (MRA and Redundancy analysis (RDA were applied as an integrated approach in a GIS environment to explore the temporal and spatial variations in river water quality and to estimate the influence of watershed land use, topography and socio-economic factors on river water quality based on 3 years of water quality monitoring data for the Cao-E River system. The statistical analysis revealed that TN, pH and temperature were generally higher in the rainy season, whereas BOD5, DO and turbidity were higher in the dry season. Spatial variations in river water quality were related to numerous anthropogenic and natural factors. Urban land use was found to be the most important explanatory variable for BOD5, CODMn, TN, DN, NH4+-N, NO3--N, DO, pH and TP. The animal husbandry output per capita was an important predictor of TP and turbidity, and the gross domestic product per capita largely determined spatial variations in EC. The remaining unexplained variance was related to other factors, such as topography. Our results suggested that pollution control of animal waste discharge in rural settlements, agricultural runoff in cropland, industrial production pollution and domestic pollution in urban and industrial areas were important within the Cao-E River basin. Moreover, the percentage of the total overall river water quality variance explained by an individual variable and/or all environmental variables (according to RDA can assist in quantitatively identifying the primary factors that control pollution at the watershed scale.

  13. Exploring the Effects of GCM Uncertainty on the Hydrology and Water Allocation of a Small Mountain Watershed in Northern British Columbia, Canada.

    Science.gov (United States)

    Hirshfield, F.; Anderson, A.; Sui, J.

    2014-12-01

    Climate change and allocation of water supplies are causing water shortages and low flow conditions that threaten aquatic ecosystems around the world. Small mountain streams in Western Canada are experiencing increased water use from small diversion hydropower, increasing population, mining, agriculture, and changing energy extraction techniques. In addition, there are very few gauging sites for baseline water data because of the rugged mountain terrain and cold climate. Baseline data is important due to the sensitivity of small mountain streams to shifts in timing of snow pack melt and mid-winter melting, especially near and in coastal regions. Here we use HBV-EC to simulate the range in future flow in a northern mountain watershed under various climate scenarios and explore the uncertainty induced by different GMC models and downscaling for the Goathorn Creek watershed. To explore the effects of GCM model variability we selected four models (CGCM3, ECHAM5, GFDL-CM2.1, and CSIRO-Mk) and used the TreeGen downscaling method to generate multiple ensembles for emissions scenarios (A1B, A2 and B1) for each GCM model. The calibrated HBV-EC model was sensitive to the climate inputs and produced a 50 percent variation in flows for the 2050's and 2080's with the greatest reduction in mean flows by 0.33 m3/s predicted for the 2020's climate. Although, modeled future discharge is highly variable, some consistent trends are useful for water managers: results suggest spring discharge may occur up to two months earlier (CGCM3, A2 scenario), but was constantly one month earlier for all emission scenarios. This can lead to feasible management strategies such as granting fewer water permits or in areas with high future demand issuing permits with provisions for future storage.

  14. Effects of land use, topography and socio-economic factors on river water quality in a mountainous watershed with intensive agricultural production in East china.

    Science.gov (United States)

    Chen, Jiabo; Lu, Jun

    2014-01-01

    Understanding the primary effects of anthropogenic activities and natural factors on river water quality is important in the study and efficient management of water resources. In this study, analysis of Variance (ANOVA), Principal component analysis (PCA), Pearson correlations, Multiple regression analysis (MRA) and Redundancy analysis (RDA) were applied as an integrated approach in a GIS environment to explore the temporal and spatial variations in river water quality and to estimate the influence of watershed land use, topography and socio-economic factors on river water quality based on 3 years of water quality monitoring data for the Cao-E River system. The statistical analysis revealed that TN, pH and temperature were generally higher in the rainy season, whereas BOD5, DO and turbidity were higher in the dry season. Spatial variations in river water quality were related to numerous anthropogenic and natural factors. Urban land use was found to be the most important explanatory variable for BOD5, CODMn, TN, DN, NH4+-N, NO3--N, DO, pH and TP. The animal husbandry output per capita was an important predictor of TP and turbidity, and the gross domestic product per capita largely determined spatial variations in EC. The remaining unexplained variance was related to other factors, such as topography. Our results suggested that pollution control of animal waste discharge in rural settlements, agricultural runoff in cropland, industrial production pollution and domestic pollution in urban and industrial areas were important within the Cao-E River basin. Moreover, the percentage of the total overall river water quality variance explained by an individual variable and/or all environmental variables (according to RDA) can assist in quantitatively identifying the primary factors that control pollution at the watershed scale.

  15. Environmental modeling and exposure assessment of sediment-associated pyrethroids in an agricultural watershed.

    Directory of Open Access Journals (Sweden)

    Yuzhou Luo

    Full Text Available Synthetic pyrethroid insecticides have generated public concerns due to their increasing use and potential effects on aquatic ecosystems. A modeling system was developed in this study for simulating the transport processes and associated sediment toxicity of pyrethroids at coupled field/watershed scales. The model was tested in the Orestimba Creek watershed, an agriculturally intensive area in California' Central Valley. Model predictions were satisfactory when compared with measured suspended solid concentration (R(2 = 0.536, pyrethroid toxic unit (0.576, and cumulative mortality of Hyalella azteca (0.570. The results indicated that sediment toxicity in the study area was strongly related to the concentration of pyrethroids in bed sediment. Bifenthrin was identified as the dominant contributor to the sediment toxicity in recent years, accounting for 50-85% of predicted toxicity units. In addition, more than 90% of the variation on the annual maximum toxic unit of pyrethroids was attributed to precipitation and prior application of bifenthrin in the late irrigation season. As one of the first studies simulating the dynamics and spatial variability of pyrethroids in fields and instreams, the modeling results provided useful information on new policies to be considered with respect to pyrethroid regulation. This study suggested two potential measures to efficiently reduce sediment toxicity by pyrethroids in the study area: [1] limiting bifenthrin use immediately before rainfall season; and [2] implementing conservation practices to retain soil on cropland.

  16. SEFIDROOD RIVER SUB-WATERSHED-DAM-ESTUARY AND DEGRADATION MODEL: A HOLISTIC APPROACH IN IRAN

    Institute of Scientific and Technical Information of China (English)

    Forood AZARI DEHKORDI; Majid F MAKHDOUM; Nobukazu NAKAGOSHI

    2003-01-01

    The major concern of this article is to address the shortcoming and outgoing effects of the human activities on the landscape patterns and their consequences in the Sefidrood River watershed in Iran. A flow of data includes three inputs; each of them belongs to one part of three zones of a fluvial system. The three parts of the Sefidrood River fluvial system include Zone 1, a sub-watershed as degradation modeling site, Zone 2, Sefidrood Dam as dam site, and Zone 3, 17km away from the Sefidrood River path to the Caspian Sea as ending point site. The degradation model in the Zone 1 provides a suitable mean for decision support system to decrease the human impacts on each small district. The maximum number for degradation coefficient belongs to the small district with the highest physiographic density, relatively cumulative activities, and a lower figure for the habitat vulnerability. The human degradation impact were not limited to the upstream. The investigation to the Sefldrood Dam and ending point of the Sefldrood River depicts that sedimentation continues as a significant visual impact in the Sefidrood Dam reservoir and the estuary.

  17. Modeling global nutrient export from watersheds

    NARCIS (Netherlands)

    Kroeze, C.; Bouwman, L.; Seitzinger, S.

    2012-01-01

    We describe how global models can be used to analyze past and future trends in nutrient export from watersheds and how such models can be used to analyze causes and effects of coastal eutrophication. Future nutrient inputs to coastal waters may be higher than today, and nutrient ratios may depart fr

  18. Artificial sweeteners in a large Canadian river reflect human consumption in the watershed.

    Science.gov (United States)

    Spoelstra, John; Schiff, Sherry L; Brown, Susan J

    2013-01-01

    Artificial sweeteners have been widely incorporated in human food products for aid in weight loss regimes, dental health protection and dietary control of diabetes. Some of these widely used compounds can pass non-degraded through wastewater treatment systems and are subsequently discharged to groundwater and surface waters. Measurements of artificial sweeteners in rivers used for drinking water production are scarce. In order to determine the riverine concentrations of artificial sweeteners and their usefulness as a tracer of wastewater at the scale of an entire watershed, we analyzed samples from 23 sites along the entire length of the Grand River, a large river in Southern Ontario, Canada, that is impacted by agricultural activities and urban centres. Municipal water from household taps was also sampled from several cities within the Grand River Watershed. Cyclamate, saccharin, sucralose, and acesulfame were found in elevated concentrations despite high rates of biological activity, large daily cycles in dissolved oxygen and shallow river depth. The maximum concentrations that we measured for sucralose (21 µg/L), cyclamate (2.4 µg/L) [corrected], and saccharin (7.2 µg/L) are the highest reported concentrations of these compounds in surface waters to date anywhere in the world. Acesulfame persists at concentrations that are up to several orders of magnitude above the detection limit over a distance of 300 km and it behaves conservatively in the river, recording the wastewater contribution from the cumulative population in the basin. Acesulfame is a reliable wastewater effluent tracer in rivers. Furthermore, it can be used to assess rates of nutrient assimilation, track wastewater plume dilution, separate human and animal waste contributions and determine the relative persistence of emerging contaminants in impacted watersheds where multiple sources confound the usefulness of other tracers. The effects of artificial sweeteners on aquatic biota in rivers and in

  19. Artificial sweeteners in a large Canadian river reflect human consumption in the watershed.

    Directory of Open Access Journals (Sweden)

    John Spoelstra

    Full Text Available Artificial sweeteners have been widely incorporated in human food products for aid in weight loss regimes, dental health protection and dietary control of diabetes. Some of these widely used compounds can pass non-degraded through wastewater treatment systems and are subsequently discharged to groundwater and surface waters. Measurements of artificial sweeteners in rivers used for drinking water production are scarce. In order to determine the riverine concentrations of artificial sweeteners and their usefulness as a tracer of wastewater at the scale of an entire watershed, we analyzed samples from 23 sites along the entire length of the Grand River, a large river in Southern Ontario, Canada, that is impacted by agricultural activities and urban centres. Municipal water from household taps was also sampled from several cities within the Grand River Watershed. Cyclamate, saccharin, sucralose, and acesulfame were found in elevated concentrations despite high rates of biological activity, large daily cycles in dissolved oxygen and shallow river depth. The maximum concentrations that we measured for sucralose (21 µg/L, cyclamate (2.4 µg/L [corrected], and saccharin (7.2 µg/L are the highest reported concentrations of these compounds in surface waters to date anywhere in the world. Acesulfame persists at concentrations that are up to several orders of magnitude above the detection limit over a distance of 300 km and it behaves conservatively in the river, recording the wastewater contribution from the cumulative population in the basin. Acesulfame is a reliable wastewater effluent tracer in rivers. Furthermore, it can be used to assess rates of nutrient assimilation, track wastewater plume dilution, separate human and animal waste contributions and determine the relative persistence of emerging contaminants in impacted watersheds where multiple sources confound the usefulness of other tracers. The effects of artificial sweeteners on aquatic biota

  20. Nonlinear cumulative damage model for multiaxial fatigue

    Institute of Scientific and Technical Information of China (English)

    SHANG De-guang; SUN Guo-qin; DENG Jing; YAN Chu-liang

    2006-01-01

    On the basis of the continuum fatigue damage theory,a nonlinear uniaxial fatigue cumulative damage model is first proposed.In order to describe multiaxial fatigue damage characteristics,a nonlinear multiaxial fatigue cumulative damage model is developed based on the critical plane approach,The proposed model can consider the multiaxial fatigue limit,mean hydrostatic pressure and the unseparated characteristic for the damage variables and loading parameters.The recurrence formula of fatigue damage model was derived under multilevel loading,which is used to predict multiaxial fatigue life.The results showed that the proposed nonlinear multiaxial fatigue cumulative damage model is better than Miner's rule.

  1. Assessment of runoff water quality for an integrated best-management practice system in an agricultural watershed

    Science.gov (United States)

    To better understand, implement and integrate best management practices (BMPs) in agricultural watersheds, critical information on their effectiveness is required. A representative agricultural watershed, Beasley Lake, was used to compare runoff water quality draining through an integrated system of...

  2. Analysis on mining-induced cumulative effective of surface cracks in mining areas%开采沉陷对矿区地表裂缝的采动累积效应分析

    Institute of Scientific and Technical Information of China (English)

    朱国宏; 连达军

    2012-01-01

    基于开采沉陷学和岩石力学理论分析矿区地表裂缝的采动累积效应.采用概率积分法、胡克定律和莫尔-库伦破坏准则等方法描述并量化地表拉伸裂缝的采动累积效应表征指标,提出了采动裂缝时间拥挤效应和采动延迟效应表征指标及采动空间拥挤效应表征指标.对研究区地表裂缝采动时间拥挤效应的实地观测与数值模拟分析结果表明,上下分层动态裂缝持续时间和永久裂缝显现时刻与地表移动活跃期吻合;采动空间拥挤效应分析结果表明,采动裂缝水平延伸长度、宽度和深度均比永久裂缝小,下分层开采裂缝比上分层发育,下山方向比其他部位裂缝发育.%The paper analyzes the mining-induced cumulative effective of surface cracks based on Mining subsidence science and rock mechanics theory. The cumulative effective characterization indexes of tension cracks were described and quantized by means of probability integral method, the hooker law and Moore-the coulomb failure criteria. The dynamic cracks duration and the permanent cracks appearance time was proposed as the evaluating indicators of the time crowded effective and the delay effective. The density, the length of horizontal extension, the width, the depth of cracks and the falls of step cracks was proposed as the evaluating indicators of the space crowded effective. Case field observation and the numerical simulation results of the time crowded effective show that the dynamic cracks duration and the permanent crack s appearance time accords with the activity period of surface movement. The space crowded effective analysis shows that the horizontal length, the width, the depth of dynamic cracks is smaller than the permanent ones. Mining cracks of lower slice more develop than cracks of upper slice. Cracks at the descends mountain direction more develop than else directions.

  3. Effects of the sequence wildfire-harvesting-coppice sprout selection on nutrient export via streamfloe in a small E. globulus watershed in Galicia (NW Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, C.; Vega, J. A.; Bara, S.; Alonso, M.; Fonturbel, T.

    2011-07-01

    An experimental study was carried out between 1987 and 1999, to assess the effect of the sequence wildfire-clear felling-coppice sprout selection thinning, on stream flow nutrient export in a Eucalyptus globulus Labill. watershed in Galicia (NW Spain). The effects of such a sequence on nutrient export via stream flow had not been previously evaluated. A wildfire in 1989 caused a significant increase in nutrient exports in stream flow during the following two years. No significant effect was observed the third year after wildfire. After clear felling in 1992, inputs via precipitation compensated for nutrient exports in stream flow, except for K the first year following harvest and NO{sub 3}- during the three years after this operation. Coppice sprout selection thinning in 1995 had less effect on nutrient exports than wildfire or harvest. The results presented here could may help in evaluating the effects of current intensive forest management and perturbations that affect eucalypt stands in NW Spain. (Author) 39 refs.

  4. Continuously Cumulating Meta-Analysis and Replicability.

    Science.gov (United States)

    Braver, Sanford L; Thoemmes, Felix J; Rosenthal, Robert

    2014-05-01

    The current crisis in scientific psychology about whether our findings are irreproducible was presaged years ago by Tversky and Kahneman (1971), who noted that even sophisticated researchers believe in the fallacious Law of Small Numbers-erroneous intuitions about how imprecisely sample data reflect population phenomena. Combined with the low power of most current work, this often leads to the use of misleading criteria about whether an effect has replicated. Rosenthal (1990) suggested more appropriate criteria, here labeled the continuously cumulating meta-analytic (CCMA) approach. For example, a CCMA analysis on a replication attempt that does not reach significance might nonetheless provide more, not less, evidence that the effect is real. Alternatively, measures of heterogeneity might show that two studies that differ in whether they are significant might have only trivially different effect sizes. We present a nontechnical introduction to the CCMA framework (referencing relevant software), and then explain how it can be used to address aspects of replicability or more generally to assess quantitative evidence from numerous studies. We then present some examples and simulation results using the CCMA approach that show how the combination of evidence can yield improved results over the consideration of single studies.

  5. The effect evaluation of the cumulative assessment model in nursing safety control%累计考核管理模式在护理安全管理中应用的效果评价

    Institute of Scientific and Technical Information of China (English)

    谢惠兰; 罗敏; 欧阳庆; 刘玉娥; 成放群; 周利华; 胡碧波; 周扬飞; 张晓玲

    2014-01-01

    目的 探索累计考核管理模式在护理安全管理中的应用及效果评价.方法 在原有“累计扣分制”被动处罚式的管理模式的基础上逐步建立主动预防式的安全管理模式.以5个试点病房为研究对象,比较实施前后护士安全意识及患者安全文化的认知、不良事件主动报告、护理质量及患者满意度的变化情况.结果 5个试点病房的护理人员安全意识及患者安全文化的认知度提高,不良事件主动呈报率较前增多,护理质量及患者满意度提高.结论 通过建立累计考核管理模式改变了以前“扣分、批评、通报、处罚”的管理模式,强化了护士的安全认知和安全行为,构建了积极的患者安全文化氛围,采用“不惩罚”及“保密”的原则,系统地收集、分析、梳理、总结、共享不良事件信息,并着重分析系统层面、管理因素、环境因素的综合成因,逐步实现从系统的角度处理安全隐患的风险管理策略,达到前馈控制安全事件的发生,形成一个利用差错信息来提高护理质量和患者安全的主动预防式管理模式.%Objective To explore the application and the effect evaluation of cumulative assessment management model in nursing safety control.Methods The original passive punishment management such as "cumulative deduction model" was gradually transformed into active precaution safety management model.The objects of research were 5 wards that the cumulative assessment model was applied to.The results were used to compare the changes of the nurses' safety consciousness,patients' safety culture cognition,spontaneous reporting of the adverse events,nursing quality and patients satisfaction before and after the implementation of active precaution safety management.Results In the 5 wards,nurses' safety consciousness and patients' safety culture cognition were improved; the spontaneous reporting of the adverse events increased and the nursing

  6. Streamflow simulation by a watershed model using stochastically generated weather in New York City watersheds

    Science.gov (United States)

    Mukundan, R.; Acharya, N.; Gelda, R.; Owens, E. M.; Frei, A.; Schneiderman, E. M.

    2016-12-01

    Recent studies have reported increasing trends in total precipitation, and in the frequency and magnitude of extreme precipitation events in the West of Hudson (WOH) watersheds of the New York City (NYC) water supply. The potential effects of these changes may pose challenges for both water quality (such as increased sediment and nutrient loading) and quantity (such as reservoir storage and management). The NYC Dept. of Environmental Protection Climate Change Integrated Modeling Project (CCIMP) is using "bottom-up" or vulnerability based methods to explore climate impacts on water resources. Stochastic weather generators (SWGs) are an integral component of the bottom-up approach. Previous work has identified and evaluated the skill of alternative stochastic weather generators of varying complexity for simulating the statistical characteristics of observed minimum and maximum daily air temperature and occurrence and amount of precipitation. This evaluation focused on the skill in representing extreme streamflow event probabilities across NYC West of Hudson (WOH) watersheds. Synthetic weather time series from the selected (skewed normal) SWG were used to drive the Generalized Watershed Loading Function (GWLF) watershed model for a 600 year long period to simulate daily streamflows for WOH watersheds under a wide range of hydrologic conditions. Long-term average daily streamflows generated using the synthetic weather time series were comparable to values generated using observed long-term (1950-2009) weather time series. This study demonstrates the ability of the selected weather generator to adequately represent the hydrologic response in WOH watersheds with respect to the total, peak, and seasonality in streamflows. Future application of SWGs in NYC watersheds will include generating multiple scenarios of changing climate to evaluate water supply system vulnerability and selection of appropriate adaptation measures.

  7. Mercury cycling in terrestrial watersheds

    Science.gov (United States)

    Shanley, James B.; Bishop, Kevin; Banks, Michael S.

    2012-01-01

    This chapter discusses mercury cycling in the terrestrial landscape, including inputs from the atmosphere, accumulation in soils and vegetation, outputs in streamflow and volatilization, and effects of land disturbance. Mercury mobility in the terrestrial landscape is strongly controlled by organic matter. About 90% of the atmospheric mercury input is retained in vegetation and organic matter in soils, causing a buildup of legacy mercury. Some mercury is volatilized back to the atmosphere, but most export of mercury from watersheds occurs by streamflow. Stream mercury export is episodic, in association with dissolved and particulate organic carbon, as stormflow and snowmelt flush organic-rich shallow soil horizons. The terrestrial landscape is thus a major source of mercury to downstream aquatic environments, where mercury is methylated and enters the aquatic food web. With ample organic matter and sulfur, methylmercury forms in uplands as well—in wetlands, riparian zones, and other anoxic sites. Watershed features (topography, land cover type, and soil drainage class) are often more important than atmospheric mercury deposition in controlling the amount of stream mercury and methylmercury export. While reductions in atmospheric mercury deposition may rapidly benefit lakes, the terrestrial landscape will respond only over decades, because of the large stock and slow turnover of legacy mercury. We conclude with a discussion of future scenarios and the challenge of managing terrestrial mercury.

  8. Cumulative cultural learning: Development and diversity.

    Science.gov (United States)

    Legare, Cristine H

    2017-07-24

    The complexity and variability of human culture is unmatched by any other species. Humans live in culturally constructed niches filled with artifacts, skills, beliefs, and practices that have been inherited, accumulated, and modified over generations. A causal account of the complexity of human culture must explain its distinguishing characteristics: It is cumulative and highly variable within and across populations. I propose that the psychological adaptations supporting cumulative cultural transmission are universal but are sufficiently flexible to support the acquisition of highly variable behavioral repertoires. This paper describes variation in the transmission practices (teaching) and acquisition strategies (imitation) that support cumulative cultural learning in childhood. Examining flexibility and variation in caregiver socialization and children's learning extends our understanding of evolution in living systems by providing insight into the psychological foundations of cumulative cultural transmission-the cornerstone of human cultural diversity.

  9. Sub-watershed prioritization based on sediment yield using game theory

    Science.gov (United States)

    Adhami, Maryam; Sadeghi, Seyed Hamidreza

    2016-10-01

    The proper placement of soil and water conservation measures cannot be designated due to lack of appropriate technical prioritization of different areas of a watershed. Therefore, quantifying soil erosion hazard and spatial prioritization of sub-watersheds would aid in better watershed management planning. Although, many approaches have been applied to prioritize sub-watersheds, but still the efficient techniques like game theory have not been practically applied to prioritize sub-watersheds. The present study therefore has used the game theory to prioritize sub-watersheds in Gorganroud and Qareh Sou watersheds in Golestan Province, northern Iran. Towards this goal, 38 independent factors were classified in seven components using Principal Component Analysis (PCA) method with one representative variable in each component. The Condorcet method used for prioritization of effective variables indicated that the percent of forestry lands (52 scores) and discharge with 10 years of return period (32 scores) were respectively the most and the least effective variables on sediment yield. The Fallback bargaining and the Borda Scoring algorithms were also selected to prioritize study sub-watersheds based on weighted grades of total score for each variable. Accordingly, the aforesaid algorithms classified sub-watersheds in three categories. Comparison of results similarly introduced Galikesh, Qazaqli, Gonbad, Siyah Ab and Tamar as first ranked sub-watersheds with the worth condition, Tangrah and Naharkhoran as second priority and eventually Pole Ordougah as sub-watershed with the lowest priority.

  10. Watershed based intelligent scissors.

    Science.gov (United States)

    Wieclawek, W; Pietka, E

    2015-07-01

    Watershed based modification of intelligent scissors has been developed. This approach requires a preprocessing phase with anisotropic diffusion to reduce subtle edges. Then, the watershed transform enhances the corridors. Finally, a roaming procedure, developed in this study, delineates the edge selected by a user. Due to a very restrictive set of pixels, subjected to the analysis, this approach significantly reduces the computational complexity. Moreover, the accuracy of the algorithm performance makes often one click point to be sufficient for one edge delineation. The method has been evaluated on structures as different in shape and appearance as the retina layers in OCT exams, chest and abdomen in CT and knee in MR studies. The accuracy is comparable with the traditional Life-Wire approach, whereas the analysis time decreases due to the reduction of the user interaction and number of pixels processed by the method.

  11. A mean field approach to watershed hydrology

    Science.gov (United States)

    Bartlett, Mark; Porporato, Amilcare

    2016-04-01

    Mean field theory (also known as self-consistent field theory) is commonly used in statistical physics when modeling the space-time behavior of complex systems. The mean field theory approximates a complex multi-component system by considering a lumped (or average) effect for all individual components acting on a single component. Thus, the many body problem is reduced to a one body problem. For watershed hydrology, a mean field theory reduces the numerous point component effects to more tractable watershed averages, resulting in a consistent method for linking the average watershed fluxes to the local fluxes at each point. We apply this approach to the spatial distribution of soil moisture, and as a result, the numerous local interactions related to lateral fluxes of soil water are parameterized in terms of the average soil moisture. The mean field approach provides a basis for unifying and extending common event-based models (e.g. Soil Conservation Service curve number (SCS-CN) method) with more modern semi-distributed models (e.g. Variable Infiltration Capacity (VIC) model, the Probability Distributed (PDM) model, and TOPMODEL). We obtain simple equations for the fractions of the different source areas of runoff, the spatial variability of runoff, and the average runoff value (i.e., the so-called runoff curve). The resulting space time distribution of soil moisture offers a concise description of the variability of watershed fluxes.

  12. Calculating Cumulative Binomial-Distribution Probabilities

    Science.gov (United States)

    Scheuer, Ernest M.; Bowerman, Paul N.

    1989-01-01

    Cumulative-binomial computer program, CUMBIN, one of set of three programs, calculates cumulative binomial probability distributions for arbitrary inputs. CUMBIN, NEWTONP (NPO-17556), and CROSSER (NPO-17557), used independently of one another. Reliabilities and availabilities of k-out-of-n systems analyzed. Used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. Used for calculations of reliability and availability. Program written in C.

  13. A cross-cultural longitudinal examination of the effect of cumulative adversity on the mental and physical health of older adults.

    Science.gov (United States)

    Palgi, Yuval; Shrira, Amit

    2016-03-01

    Self-oriented adversity refers to traumatic events that primarily inflict the self, whereas other-oriented adversity refers to events that affect the self by primarily targeting others. The present study aimed to examine whether cultural background moderates the effects of self-oriented and other-oriented adversity on mental and physical health of older adults. Using longitudinal data from the Israeli component of the Survey of Health and Retirement, we focused on 370 Jews and 239 Arabs who reported their exposure to various adversities across the life span, and completed questionnaires regarding mental and physical health. Results showed that the effect of self-oriented adversity on health did not differ among Jews and Arabs. However, other-oriented adversity showed a stronger effect on Arabs' mental and physical health than on Jews' health. Our findings suggest that the accumulation of adverse events that affect the self by primarily targeting others may have a stronger impact in collectivist cultures than in individualist cultures.

  14. Ghana Watershed Prototype Products

    Science.gov (United States)

    ,

    2007-01-01

    Introduction/Background A number of satellite data sets are available through the U.S. Geological Survey (USGS) for monitoring land surface features. Representative data sets include Landsat, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), and Shuttle Radar Topography Mission (SRTM). The Ghana Watershed Prototype Products cover an area within southern Ghana, Africa, and include examples of the aforementioned data sets along with sample SRTM derivative data sets.

  15. Land cover and future climate effects on the provision of hydrological services: SWAT applied to a medium-sized watershed of northern Portugal

    Science.gov (United States)

    Carvalho-Santos, Claudia; Nunes, João Pedro; Monteiro, António T.; Hein, Lars; Honrado, João

    2015-04-01

    Land cover change and future climate conditions may influence the provision of hydrological services. Therefore, it is important to understand how these drivers will affect water supplies and water hazards mitigation, in order to support the planning and management of water resources. In this study, the separated and combined effects of land cover and future climate on the hydrology of the Vez watershed, northern Portugal, were evaluated. The Vez watershed (252 Km2) has a humid climate regime where precipitation is abundant all over the year (1500mm/yr), with exception of a summer with almost no rain. The SWAT (Soil and Water Assessment Tool) model was calibrated against daily discharge, sediments and nitrates, with good agreements between model predictions and field observations related with discharge; the calibration of sediments and nitrates can be considered adequate given the limitations of observed data. Four hypothetical land cover scenarios were applied under current climate conditions (eucalyptus/pine, oak, agriculture/vine and low vegetation). Results for land cover revealed that the option for one particular scenario would not compromise the overall provision of hydrological services. However, the eucalyptus/pine scenario could reduce the annual water quantity by 7%, and up to 17% in the summer period; and the agriculture/vine scenario could increase soil erosion and nitrate exports. For the future climate scenario, a statistical downscaling of four ensemble GCMs (General Circulation Models), bias-corrected with ground observations was done for 2021-40 and 2041-60, using the RCP 4.5 medium emissions scenario. An increase in temperature (annual: 1.6°C; summer: 2.02°C) and a decrease in precipitation (annual: -3.9%), more pronounced in summer (-25%) are expected in the Vez watershed. Although climate change has only a modest effect in the reduction of the total annual discharge (-7%), the effect on streamflow during summer can be more pronounced (between

  16. Cumulative cultural evolution: the role of teaching.

    Science.gov (United States)

    Castro, Laureano; Toro, Miguel A

    2014-04-21

    In humans, cultural transmission occurs usually by cumulative inheritance, generating complex adaptive behavioral features. Cumulative culture requires key psychological processes (fundamentally imitation and teaching) that are absent or impoverished in non-human primates. In this paper we analyze the role that teaching has played in human cumulative cultural evolution. We assume that a system of cumulative culture generates increasingly adaptive behaviors, that are also more complex and difficult to imitate. Our thesis is that, as cultural traits become more complex, cumulative cultural transmission requires teaching to ensure accurate transmission from one generation to the next. In an increasingly complex cultural environment, we consider that individuals commit errors in imitation. We develop a model of cumulative cultural evolution in a changing environment and show that these errors hamper the process of cultural accumulation. We also show that a system of teaching between parents and offspring that increases the fidelity of imitation unblocks the accumulation and becomes adaptive whenever the gain in fitness compensates the cost of teaching.

  17. Human cumulative culture: a comparative perspective.

    Science.gov (United States)

    Dean, Lewis G; Vale, Gill L; Laland, Kevin N; Flynn, Emma; Kendal, Rachel L

    2014-05-01

    Many animals exhibit social learning and behavioural traditions, but human culture exhibits unparalleled complexity and diversity, and is unambiguously cumulative in character. These similarities and differences have spawned a debate over whether animal traditions and human culture are reliant on homologous or analogous psychological processes. Human cumulative culture combines high-fidelity transmission of cultural knowledge with beneficial modifications to generate a 'ratcheting' in technological complexity, leading to the development of traits far more complex than one individual could invent alone. Claims have been made for cumulative culture in several species of animals, including chimpanzees, orangutans and New Caledonian crows, but these remain contentious. Whilst initial work on the topic of cumulative culture was largely theoretical, employing mathematical methods developed by population biologists, in recent years researchers from a wide range of disciplines, including psychology, biology, economics, biological anthropology, linguistics and archaeology, have turned their attention to the experimental investigation of cumulative culture. We review this literature, highlighting advances made in understanding the underlying processes of cumulative culture and emphasising areas of agreement and disagreement amongst investigators in separate fields.

  18. Southern Watersheds Common Reed Project, Final Report [Draft

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Southern Watersheds Common Reed Project is an interagency effort to demonstrate effective control of the invasive wetland plant, common reed, while...

  19. Cumulative psychosocial stress, coping resources, and preterm birth.

    Science.gov (United States)

    McDonald, Sheila W; Kingston, Dawn; Bayrampour, Hamideh; Dolan, Siobhan M; Tough, Suzanne C

    2014-12-01

    Preterm birth constitutes a significant international public health issue, with implications for child and family well-being. High levels of psychosocial stress and negative affect before and during pregnancy are contributing factors to shortened gestation and preterm birth. We developed a cumulative psychosocial stress variable and examined its association with early delivery controlling for known preterm birth risk factors and confounding environmental variables. We further examined this association among subgroups of women with different levels of coping resources. Utilizing the All Our Babies (AOB) study, an ongoing prospective pregnancy cohort study in Alberta, Canada (n = 3,021), multinomial logistic regression was adopted to examine the independent effect of cumulative psychosocial stress and preterm birth subgroups compared to term births. Stratified analyses according to categories of perceived social support and optimism were undertaken to examine differential effects among subgroups of women. Cumulative psychosocial stress was a statistically significant risk factor for late preterm birth (OR = 1.73; 95 % CI = 1.07, 2.81), but not for early preterm birth (OR = 2.44; 95 % CI = 0.95, 6.32), controlling for income, history of preterm birth, pregnancy complications, reproductive history, and smoking in pregnancy. Stratified analyses showed that cumulative psychosocial stress was a significant risk factor for preterm birth at psychosocial stress on the risk for early delivery.

  20. Effects of residential and agricultural land uses on the chemical quality of baseflow of small streams in the Croton Watershed, southeastern New York

    Science.gov (United States)

    Heisig, Paul M.

    2000-01-01

    Data on the chemical quality of baseflow from 33 small streams that drain basins of differing land-use type and intensity within the Croton watershed were collected seasonally for 1 year to identify and characterize the quality of ground-water contributions to surface water. The watershed includes twelve of New York City's water-supply reservoirs. Baseflow samples were collected a minimum of three days after the most recent precipitation and were analyzed for major ions, boron, and nutrients.

  1. The Cumulative Neurobehavioral and Physiological Effects of Chronic Caffeine Intake: Individual Differences and Implications for the Use of Caffeinated Energy Products

    Science.gov (United States)

    Spaeth, Andrea M; Goel, Namni; Dinges, David F

    2014-01-01

    The use of caffeine-containing energy products (CCEP) has increased worldwide in recent years and research shows that CCEP can improve cognitive and physical performance. All of the top-selling energy drinks contain caffeine, which is likely to be the primary psychoactive ingredient in CCEP. Presumably, individuals consume CCEP to counteract feelings of ‘low-energy’ in situations causing tiredness, fatigue, and/or reduced alertness. This review discusses the scientific evidence for sleep loss, circadian phase, sleep inertia and the time-on-task effect as causes of ‘low energy’ and summarizes research assessing the efficacy of caffeine to counteract decreased alertness and increased fatigue in such situations. The results of a placebo-controlled experiment on healthy adults undergoing three nights of total sleep deprivation (with or without 2 hour naps every 12 hours) are presented to illustrate the physiological and neurobehavioral effects of sustained low-dose caffeine. Individual differences, including genetic factors, in the response to caffeine and to sleep loss are discussed. We conclude with future directions for research on this important and evolving topic. PMID:25293542

  2. Hydrologic Causes and Effects of Vegetation State Change in the Semiarid Southwest US: Observations and Model Results From a Small, Instrumented Watershed

    Science.gov (United States)

    Schreiner-McGraw, A.; Vivoni, E. R.

    2016-12-01

    Vegetation has changed dramatically over the last 150 years in the southwest United States due to a combination of overgrazing, climate change, and fire suppression. These changes are hypothesized to have had profound effects on the hydrologic cycle. In this study, we use a combination of long-term observations and a hydrologic model to investigate the causes of vegetation change and it's effects on hydrology in a semiarid catchment in New Mexico, USA. Our study site has undergone transitions between shrub dominance states. In this study we test two hypotheses: (1) the timing of plant available water combined with differing shrub phenologies has controlled changes in shrub dominance state, and (2) changes in the dominant shrub type will affect runoff and deep recharge from the watershed. Long-term data sets from the Jornada LTER allow us to compare previous vegetation states to the historical rainfall record. As the ecosystem shifted from tarbush-dominated to creosote-dominated to a mixed scrubland with mesquite establishment, we observed increases in the percent of annual rainfall that falls early in the growing season (GS; 3%, p = 0.04), the amount of large storms (>10 mm; 121%, p = 0.03), and the total rainfall (+30.4 mm, p = 0.03) during the early GS. We use data from satellites, UAV flights, and ground-based measurements to show that mesquite and creosote are most active during the early GS (April-July), while tarbush is most active during the late GS (August-November). To extend this analysis, we make use of a hydrologic model, tRIBS, that has vegetation phenology implemented for each of the target species. We built a present-time model based on vegetation classification from UAV flights and parameterization by field measurements. We calibrated and validated this model, then we built model scenarios based on historical vegetation maps and observed changes in soil properties. Model simulations demonstrate the strength of the phenological control on the

  3. The selective neuronal nitric oxide synthase inhibitor 7-nitroindazole has acute analgesic but not cumulative effects in a rat model of peripheral neuropathy

    Directory of Open Access Journals (Sweden)

    Henry JL

    2011-03-01

    Full Text Available Liliane J Dableh, James L HenryDepartment of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, CanadaAbstract: Chronic neuropathic pain that may arise from various nerve injuries or insults remains notoriously difficult to manage. The neuronal isoform of the enzyme nitric oxide synthase (nNOS has been shown to be involved in the spinal transmission of nociception in animal models of chronic pain. The aim of this study is to evaluate the effect of single dose and repeated administration of a selective nNOS inhibitor. Rats were unilaterally implanted with a 2-mm polyethylene cuff around the sciatic nerve. Paw withdrawal thresholds were measured using von Frey filament stimulation. Rats were given 10, 20, or 30 mg/kg of 7-nitroindazole (7-NI, or vehicle, on days 2, 5, and 7 after model induction, respectively. Paw withdrawal thresholds were measured before and at 30 and 60 min after injection. 7-NI significantly increased paw withdrawal thresholds at 60 min at the 20 and 30 mg/kg dosages. In the second part of this study, rats were given 20 mg/kg 7-NI daily for five days starting immediately after cuff implantation (days 0 to 4, and the cuff was removed on day 4. Withdrawal thresholds were measured intermittently over a 24-day observation period. No differences in withdrawal thresholds were observed between drug and vehicle-treated rats. Therefore, early and repeated administration of 7-NI did not affect the development or progression of the model. In conclusion, inhibition of nNOS had an analgesic but not a pre-emptive effect in this model of peripheral neuropathic pain.Keywords: neuronal nitric oxide synthase, nitric oxide, 7-nitroindazole, neuropathic pain, peripheral nerve injury, nociception 

  4. Watershed Ecohydrology: How Do Vegetation Patterns and Climate Affect Watershed Storage and Connectivity?

    Science.gov (United States)

    Nippgen, F.; McGlynn, B. L.; Emanuel, R. E.

    2015-12-01

    Topography and soils have long been recognized as mediators of runoff source areas, but the effect of vegetation patterns on subsurface throughflow is less well understood. While numerous studies have shown that vegetation removal generally leads to increases in streamflow, few studies have examined the intersection between patterns of evapotranspiration and topographically driven patterns of throughflow generation and connectivity. We applied a parsimonious but spatially distributed watershed modeling framework (WECOH: Watershed ECOHydrology Model) to a snow dominated watershed in central Montana to elucidate how different vegetation scenarios and climate forcing can affect the temporal evolution of storage distributions and watershed connectivity. We derived spatially distributed snowmelt and rainfall input from two NRCS SNOTEL sites located in the experimental watershed and actual evapotranspiration from a co-located eddy-covariance tower. We generated different vegetation scenarios to simulate forest harvesting and compared streamflow response, spatial distribution of storage, and runoff source areas across scenarios. Our work aims at better understanding how the intersection of vegetation and topography mediates hydrologic response.

  5. Cumulative abiotic stresses and their effect on the antioxidant defense system in two species of wheat, Triticum durum Desf and Triticum aestivum L.

    Directory of Open Access Journals (Sweden)

    Ibrahim M.M.

    2013-01-01

    Full Text Available The combined effects of heat and UV-B on the antioxidant system and photosynthetic pigments were investigated in the leaves of T. durum Desf. and Triticum aestivum L. The photosynthetic pigment content, in vitro evaluation of the antioxidant system activities including DPPH radical scavenging activity, and super oxide anion radical scavenging activity were determined. In addition, the antioxidant enzyme activities, such as superoxide dismutase (SOD and guaiacol peroxidase (GPX, were determined. Heat and UV-B irradiation alone caused a significant decrease in the photosynthetic pigment content, radical scavenging activity and super oxide radical scavenging activity in the two studied plants. The antioxidant enzymes SOD and GPX were stimulated in response to UV and/or heat stresses. The elevation of enzyme activities was higher under heat than under UV-B, especially in T. aestivum. According to our findings, it can be concluded that combined heat and UV-B provided cross-tolerance; otherwise, single stress was found to aggravate the responses.

  6. Cumulative effect of gibberellic acid and phosphorus on crop productivity, biochemical activities and trigonelline production in Trigonella foenum-graecum L.

    Directory of Open Access Journals (Sweden)

    Tariq Ahmad Dar

    2015-12-01

    Full Text Available Fenugreek (Trigonella foenum-graecum L. is an antidiabetic plant. Its bioactive compound, trigonelline, is known to counter diabetes through insulin secretion, modulation of β cell regeneration and quick activity of glucose metabolism related enzymes. A pot experiment was conducted in the natural conditions of net house of the Department of Botany, Aligarh Muslim University, Aligarh (UP, India, to evaluate the effect of four concentrations of GA3 (0, 10−7 M, 10−6 M and 10−5 M, alone and in combination with phosphorus (40 kg P ha−1, on growth, biochemical and yield attributes of fenugreek. Compared to control, the combination of GA3 and phosphorus (P40 + 10−6 M GA3 significantly increased the activities of nitrate reductase (30.8% and carbonic anhydrase (30.7% enzymes; it also enhanced the seed yield (140.6% and the content of total chlorophyll (28.5% and carotenoids (26%. There was also significant increase (19.51% in the content of seed trigonelline.

  7. Watershed management for water supply in developing world city

    Institute of Scientific and Technical Information of China (English)

    车越; 杨凯; 吕永鹏; 张宏伟; 吴健; 杨永川

    2009-01-01

    The water supply system in Shanghai provides about 2.55×109 m3/a,of which more than 50% is derived from the Upper Huangpu River Watershed. During the process of rapid urbanization and industrialization,the role of watershed management in sustaining clean drinking water quality at surface sources is emphasized in Shanghai. This paper proposes an integrated watershed management (IWM) approach in the context of the current pressures and problems of source water protection at the Upper Huangpu River Watershed in Shanghai. Based on data sets of land use,water quality and regional development,multi-criteria analysis and system dynamics techniques were used to evaluate effectiveness and improve decision-making of source water protection at a watershed scale. Different scenarios for potential source water quality changing from 2008 to 2020 were predicted,based on a systematic analysis and system dynamics modeling,a watershed management approach integrating land use prioritization and stakeholder involvement was designed to conserve the source water quality. The integrated watershed management (IWM) approach may help local authorities better understand and address the complex source water system,and develop improved safe drinking water strategies to better balance urban expansion and source water protection.

  8. Slope spectrum variation in a simulated loess watershed

    Science.gov (United States)

    Li, Fayuan; Tang, Guoan; Wang, Chun; Cui, Lingzhou; Zhu, Rui

    2016-06-01

    A simulated loess watershed, where the loess material and relief properly represent the true loess surface, is adopted to investigate the variation in slope spectrum with loess watershed evolution. The evolution of the simulated loess watershed was driven by the exogenetic force of artificial rainfall. For a period of three months, twenty artificial rainfall events with different intensities and durations were carried out. In the process, nine DEM data sets, each with 10 mm grid resolution, were established by the method of close-range photogrammetry. The slope spectra were then extracted from these DEMs. Subsequent series of carefully designed quantitative analyses indicated a strong relationship between the slope spectrum and the evolution of the simulated loess watershed. Quantitative indices of the slope spectrum varied regularly following the evolution of the simulated loess watershed. Mean slope, slope spectrum information entropy ( H), terrain driving force ( T d ), Mean patch area ( AREA_MN), Contagion Index ( CONTAG), and Patch Cohesion Index ( COHESION) kept increasing following the evolution of the simulated watershed, while skewness ( S), Perimeter-Area Fractal Dimension ( PAFRAC), and Interspersion and Juxtaposition Index ( IJI) represented an opposite trend. All the indices changed actively in the early and active development periods, but slowly in the stable development periods. These experimental results indicate that the time series of slope spectra was able to effectively depict the slope distribution of the simulated loess watershed, thus presenting a potential method for modeling loess landforms.

  9. Watershed councils: it takes a community to restore a watershed

    Science.gov (United States)

    Marie Oliver; Rebecca Flitcroft

    2011-01-01

    Regulation alone cannot solve complex ecological problems on private lands that are managed for diverse uses. Executing coordinated restoration projects at the watershed scale is only possible with the cooperation and commitment of all stakeholders. Locally organized, nonregulatory watershed councils have proven to be a powerful method of engaging citizens from all...

  10. An integrated multi-level watershed-reservoir modeling system for examining hydrological and biogeochemical processes in small prairie watersheds.

    Science.gov (United States)

    Zhang, Hua; Huang, Guo H; Wang, Dunling; Zhang, Xiaodong; Li, Gongchen; An, Chunjiang; Cui, Zheng; Liao, Renfei; Nie, Xianghui

    2012-03-15

    Eutrophication of small prairie reservoirs presents a major challenge in water quality management and has led to a need for predictive water quality modeling. Studies are lacking in effectively integrating watershed models and reservoir models to explore nutrient dynamics and eutrophication pattern. A water quality model specific to small prairie water bodies is also desired in order to highlight key biogeochemical processes with an acceptable degree of parameterization. This study presents a Multi-level Watershed-Reservoir Modeling System (MWRMS) to simulate hydrological and biogeochemical processes in small prairie watersheds. It integrated a watershed model, a hydrodynamic model and an eutrophication model into a flexible modeling framework. It can comprehensively describe hydrological and biogeochemical processes across different spatial scales and effectively deal with the special drainage structure of small prairie watersheds. As a key component of MWRMS, a three-dimensional Willows Reservoir Eutrophication Model (WREM) is developed to addresses essential biogeochemical processes in prairie reservoirs and to generate 3D distributions of various water quality constituents; with a modest degree of parameterization, WREM is able to meet the limit of data availability that often confronts the modeling practices in small watersheds. MWRMS was applied to the Assiniboia Watershed in southern Saskatchewan, Canada. Extensive efforts of field work and lab analysis were undertaken to support model calibration and validation. MWRMS demonstrated its ability to reproduce the observed watershed water yield, reservoir water levels and temperatures, and concentrations of several water constituents. Results showed that the aquatic systems in the Assiniboia Watershed were nitrogen-limited and sediment flux played a crucial role in reservoir nutrient budget and dynamics. MWRMS can provide a broad context of decision support for water resources management and water quality

  11. Pesticides in Ichkeul Lake-Bizerta Lagoon Watershed in Tunisia: use, occurrence, and effects on bacteria and free-living marine nematodes.

    Science.gov (United States)

    Salem, Fida Ben; Said, Olfa Ben; Aissa, Patricia; Mahmoudi, Ezzeddine; Monperrus, Mathilde; Grunberger, Olivier; Duran, Robert

    2016-01-01

    This study aimed to identify the most commonly used agricultural pesticides around Ichkeul Lake-Bizerta Lagoon watershed. First survey of pesticide use on agricultural watershed was performed with farmers, Regional Commissioner for Agricultural Development, and pesticide dealers. Then, sediment contamination by pesticides and response of benthic communities (bacteria and free-living marine nematode) were investigated. The analysis of 22 active organochlorine pesticides in sediments was performed according to quick, easy, cheap, effective, rugged, and safe (QuEChERS) method, biodiversity of indigenous bacterial community sediment was determined by terminal restriction fragment length polymorphism (T-RFLP), and free-living marine nematodes were counted. The results of the field survey showed that iodosulfuron, mesosulfuron, 2,4-dichlorophenoxyacetic acid (2,4 D), glyphosate, and fenoxaprops were the most used herbicides, tebuconazole and epoxiconazole the most used fungicides, and deltamethrin the most used insecticide. Sixteen organochlorine pesticide compounds among the 22 examined were detected in sediments up to 2 ppm in Ichkeul Lake, endrin, dieldrin, and hexachlorocyclohexane being the most detected molecules. The most pesticide-contaminated site in the lake presented the higher density of nematode, but when considering all sites, no clear correlation with organochlorine pesticide (OCP) content could be established. The bacterial community structure in the most contaminated site in the lake was characterized by the terminal restriction fragments (T-RFs) 97, 146, 258, 285, and 335 while the most contaminated site in the lagoon was characterized by the T-RFs 54, 263, 315, 403, and 428. Interestingly, T-RFs 38 and 143 were found in the most contaminated sites of both lake and lagoon ecosystems, indicating that they were resistant to OCPs and able to cope with environmental fluctuation of salinity. In contrast, the T-RFs 63, 100, 118, and 381 in the lake and the T

  12. [Effects of land use and landscape pattern on nitrogen and phosphorus exports in Lanlingxi Watershed of the Three Gorges Reservoir Area, China].

    Science.gov (United States)

    Han, Li-Yang; Huang, Zhi-Lin; Xiao, Wen-Fa; Tian, Yao-Wu; Zeng, Li-Xiong; Wu, Dong

    2014-03-01

    The temporal and spatial characteristics of N, P exports and effects of land use and landscape pattern on N, P exports were analyzed in the Lanlingxi Watershed of the Three Gorges Reservoir Area. The results showed that the TN, TP and NO3(-) -N were mainly generated by non-wood forest, the N, P exports in flood period (June to September) were significantly higher than the non-flood period (January to May). The NH4(+) -N export was derived from the residential area in the non-flood period, while from non-wood forest in the flood period. In addition, the performance of samples N, P exports with forest distributed were lower in both two periods. Also, the proportion of forest significantly negatively correlated with NO3(-) -N, TP in the non-flood period and TN, TP in the flood period. The residential area proportion notably positively correlated with NO3(-) -N, TN in non-flood period and NO3(-) -N, TN, TP in the flood period. The non-wood forest proportion also significantly positively correlated with NH4(+) -N, TN in the flood period. Moreover, PD closely positively correlated with N exports in non-flood period, with NO3(-) -N, NH4(+) -N in flood period. The CONT index strongly negatively correlated with N exports in flood period and TP in non-flood period. However, the proportions of farmland, unused land and the indices of ED were relatively weakened with N, P exports in both periods, while SHMN and water proportion did not show any positive or negative correlation. Moreover, the regression fitting degree of NH4(+)-N was superior to NO3(-) -N, TN and TP with the adjust R2 of 0.885 and 0.969 in two periods, while the regression relation was better than that of non-flood period. The result of redundancy analysis further demonstrated that the landscape fragmentation caused by patches types of different land uses could better explain impacts on the exports of nitrogen and phosphorus. The two canonical axes accumulated explained the 90% proportion of the variables and

  13. Predicting Cumulative Incidence Probability by Direct Binomial Regression

    DEFF Research Database (Denmark)

    Scheike, Thomas H.; Zhang, Mei-Jie

    Binomial modelling; cumulative incidence probability; cause-specific hazards; subdistribution hazard......Binomial modelling; cumulative incidence probability; cause-specific hazards; subdistribution hazard...

  14. Water quality trading opportunities in two sub-watersheds in the northern Lake Okeechobee watershed.

    Science.gov (United States)

    Corrales, Juliana; Naja, G Melodie; Bhat, Mahadev G; Miralles-Wilhelm, Fernando

    2017-03-25

    For decades, the increase of nutrient enrichment has threatened the ecological integrity and economic sustainability of many rivers, lakes, and coastal waters, including Lake Okeechobee, the second largest freshwater lake in the contiguous United States. Water quality trading programs have been an area of active development to both, reduce nutrient pollution and minimize abatement costs. The objective of this study was to apply a comprehensive modeling framework, integrating a hydrologic-water quality model with an economic model, to assess and compare the cost-effectiveness of a water quality trading program over a command-and-control approach in order to reduce phosphorus loadings to Lake Okeechobee. The Upper Kissimmee (UK) and Taylor Creek/Nubbin Slough (TCNS) sub-watersheds, identified as major sources of total phosphorus (TP) loadings to the lake, were selected for this analysis. The effect of different caps on the market potential was assessed while considering four factors: the least-cost abatement solutions, credit prices, potential cost savings, and credit supply and demand. Hypothetical trading scenarios were also developed, using the optimal caps selected for the two sub-watersheds. In both sub-watersheds, a phosphorus credit trading program was less expensive than the conventional command-and-control approach. While attaining cost-effectiveness, keeping optimal credit prices, and fostering market competition, phosphorus reduction targets of 46% and 32% were selected as the most appropriate caps in the UK and TCNS sub-watersheds, respectively. Wastewater treatment facilities and urban areas in the UK, and concentrated animal feeding operations in the TCNS sub-watershed were identified as potential credit buyers, whereas improved pastures were identified as the major credit sellers in both sub-watersheds. The estimated net cost savings resulting from implementing a phosphorus trading program in the UK and TCNS sub-watersheds were 76% ($ 34.9 million per

  15. SPECIFIC DEGRADATION OF WATERSHEDS

    Institute of Scientific and Technical Information of China (English)

    Boubacar KANE; Pierre Y.JULIEN

    2007-01-01

    An extensive database of reservoir sedimentation surveys throughout continental United States is compiled and analyzed to determine specific degradation SD relationships as function of mean annual rainfall R, drainage area A, and watershed slope S. The database contains 1463 field measurements and specific degradation relationships are defined as function of A, R and S. Weak trends and significant variability in the data are noticeable. Specific degradation measurements are log normally distributed with respect to R, A, and S and 95% confidence intervals are determined accordingly. The accuracy of the predictions does not significantly increase as more independent variables are added to the regression analyses.

  16. The U.S. Forest Service's analysis of cumulative effects to wildlife: A study of legal standards, current practice, and ongoing challenges on a National Forest

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, Courtney A., E-mail: courtney.schultz@colostate.edu

    2012-01-15

    Cumulative effects analysis (CEA) allows natural resource managers to understand the status of resources in historical context, learn from past management actions, and adapt future activities accordingly. U.S. federal agencies are required to complete CEA as part of environmental impact assessment under the National Environmental Policy Act (NEPA). Past research on CEA as part of NEPA has identified significant deficiencies in CEA practice, suggested methodologies for handling difficult aspects of CEA, and analyzed the rise in litigation over CEA in U.S. courts. This article provides a review of the literature and legal standards related to CEA as it is done under NEPA and then examines current practice on a U.S. National Forest, utilizing qualitative methods in order to provide a detailed understanding of current approaches to CEA. Research objectives were to understand current practice, investigate ongoing challenges, and identify impediments to improvement. Methods included a systematic review of a set of NEPA documents and semi-structured interviews with practitioners, scientists, and members of the public. Findings indicate that the primary challenges associated with CEA include: issues of both geographic and temporal scale of analysis, confusion over the purpose of the requirement, the lack of monitoring data, and problems coordinating and disseminating data. Improved monitoring strategies and programmatic analyses could support improved CEA practice.

  17. Cumulative Culture and Future Thinking: Is Mental Time Travel a Prerequisite to Cumulative Cultural Evolution?

    Science.gov (United States)

    Vale, G. L.; Flynn, E. G.; Kendal, R. L.

    2012-01-01

    Cumulative culture denotes the, arguably, human capacity to build on the cultural behaviors of one's predecessors, allowing increases in cultural complexity to occur such that many of our cultural artifacts, products and technologies have progressed beyond what a single individual could invent alone. This process of cumulative cultural evolution…

  18. Cumulative second-harmonic generation of Lamb waves propagating in a two-layered solid plate

    Institute of Scientific and Technical Information of China (English)

    Xiang Yan-Xun; Deng Ming-Xi

    2008-01-01

    The physical process of cumulative second-harmonic generation of Lamb waves propagating in a two-layered solid plate is presented by using the second-order perturbation and the technique of nonlinear reflection of acoustic waves at an interface.In general,the cumulative second-harmonic generation of a dispersive guided wave propagation does not occur.However,the present paper shows that the second-harmonic of Lamb wave propagation arising from the nonlinear interaction of the partial bulk acoustic waves and the restriction of the three boundaries of the solid plates does have a cumulative growth effect if some conditions are satisfied.Through boundary condition and initial condition of excitation,the analytical expression of cumulative second-harmonic of Lamb waves propagation is determined.Numerical results show the cumulative effect of Lamb waves on second-harmonic field patterns.

  19. The simulated effects of wastewater-management actions on the hydrologic system and nitrogen-loading rates to wells and ecological receptors, Popponesset Bay Watershed, Cape Cod, Massachusetts

    Science.gov (United States)

    Walter, Donald A.

    2013-01-01

    The discharge of excess nitrogen into Popponesset Bay, an estuarine system on western Cape Cod, has resulted in eutrophication and the loss of eel grass habitat within the estuaries. Septic-system return flow in residential areas within the watershed is the primary source of nitrogen. Total Maximum Daily Loads (TMDLs) for nitrogen have been assigned to the six estuaries that compose the system, and local communities are in the process of implementing the TMDLs by the partial sewering, treatment, and disposal of treated wastewater at wastewater-treatment facilities (WTFs). Loads of waste-derived nitrogen from both current (1997–2001) and future sources can be estimated implicitly from parcel-scale water-use data and recharge areas delineated by a groundwater-flow model. These loads are referred to as “instantaneous” loads because it is assumed that the nitrogen from surface sources is delivered to receptors instantaneously and that there is no traveltime through the aquifer. The use of a solute-transport model to explicitly simulate the transport of mass through the aquifer from sources to receptors can improve implementation of TMDLs by (1) accounting for traveltime through the aquifer, (2) avoiding limitations associated with the estimation of loads from static recharge areas, (3) accounting more accurately for the effect of surface waters on nitrogen loads, and (4) determining the response of waste-derived nitrogen loads to potential wastewater-management actions. The load of nitrogen to Popponesset Bay on western Cape Cod, which was estimated by using current sources as input to a solute-transport model based on a steady-state flow model, is about 50 percent of the instantaneous load after about 7 years of transport (loads to estuary are equal to loads discharged from sources); this estimate is consistent with simulated advective traveltimes in the aquifer, which have a median of 5 years. Model-calculated loads originating from recharge areas reach 80

  20. Cumulative social disadvantage and child health.

    Science.gov (United States)

    Bauman, Laurie J; Silver, Ellen J; Stein, Ruth E K

    2006-04-01

    Disparities in child health are a major public health concern. However, it is unclear whether these are predominantly the result of low income, race, or other social risk factors that may contribute to their health disadvantage. Although others have examined the effects of the accumulation of risk factors, this methodology has not been applied to child health. We tested 4 social risk factors (poverty, minority race/ethnicity, low parental education, and not living with both biological parents) to assess whether they have cumulative effects on child health and examined whether access to health care reduced health disparities. We analyzed data on 57,553 children low parental education, and single-parent household) were consistently associated with child health. These were summed, generating the Social Disadvantage Index (range: 0-3). A total of 43.6% of children had no social disadvantages, 30.8% had 1, 15.6% had 2, and 10.0% had all 3. Compared with those with no social disadvantages, the odds ratios (ORs) of being in "good, fair, or poor health" (versus "excellent or very good") were 1.95 for 1 risk, 3.22 for 2 risks, an