1,574 research outputs found

    On the importance of including vegetation dynamics in Budyko's hydrological model

    Get PDF
    The Budyko curve describes the patterns observed between between climate, evapotranspiration and run-off and has proven to be a useful model for predicting catchment energy and water balances. In this paper we review the Budyko curve's underlying framework and, based on the literature, present an argument for why it is important to include vegetation dynamics into the framework for some purposes. The Budyko framework assumes catchments are at steady-state and are driven by the macro-climate, two conditions dependent on the scales of application, such that the framework's reliability is greatest when applied using long-term averages (≫1 year) and to large catchments (> 10 000 km2). At these scales previous experience has shown that the hydrological role of vegetation does not need to be explicitly considered within the framework. By demonstrating how dynamics in the leaf area, photosynthetic capacity and rooting depth of vegetation affect not only annual and seasonal vegetation water use, but also steady-state conditions, we argue that it is necessary to explicitly include vegetation dynamics into the Budyko framework before it is applied at small scales. Such adaptations would extend the framework not only to applications at small timescales and/or small catchments but to operational activities relating to vegetation and water management

    Who Supports Voter Identification?

    Get PDF
    The purpose of this study was to compare and contrast the differences in attitudes from the perspective of African Americans and Caucasian voters in the U.S. In addition, this study examined conscience or unconscious bias toward voter identification laws. In particular, were the effects of voter identification laws viewed through different lens depending on a voter’s ethnic background, social economic status, gender, age, or a voter’s political ideology? I approach this research by examining the results of research conducted by Michael Dawson, Lawrence Bobo, David Wilson, and Paul Brewer. These experts examined both ends of the political spectrum consisting of data from pro-voter id supporters and anti-voter identification supporters. The first hypothesis was the African American community and the cohesiveness race plays a vital role with a focus encompassing civil rights and the perseverance and enhancement of economic equality. The second hypothesis stated that a much higher percentage of Caucasian voters were supportive of voter identification laws. Many of these voters stated that voter identification laws must be implemented in an effort of preventing voter fraud. The third hypothesis was that African American voters should respond to voter identification laws with that of repugnance. Brewer and Wilson’s findings revealed that an overwhelming percentage of voters supported identification laws (78%), 21% opposed identification laws, 48% of voters stated that voter fraud was a major concern, while 43% expressed concern of denying eligible voters the right to vote

    Impact of CO2 fertilization on maximum foliage cover across the globe's warm, arid environments

    Get PDF
    Satellite observations reveal a greening of the globe over recent decades. The role in this greening of the "CO2 fertilization" effect-the enhancement of photosynthesis due to rising CO2 levels-is yet to be established. The direct CO2 effect on vegetatio

    Performance indicators for primary care groups; an evidence-based approach

    Get PDF
    The NHS Executive and Department of Health have proposed a wide range of performance indicators many of which are applicable to future primary care groups Some of these indicators reflect access and efficiency, but few of the effectiveness indicators are based on primary care interventions for which there is evidence that increased uptake results in improved health outcomes We present a method to identify important primary care interventions of proved efficacy and suggest performance indicators that could monitor their use Our evidence based approach may be a complementary way of identifying areas for performance indicators to those proposed by the NHS Executive and Department of Health Our suggested indicators are more likely to help turn evidence into everyday practice and to have an impact on the population's healt

    Shareholder Litigation

    Get PDF

    The complexity of the California recall election

    Get PDF
    The October 7, 2003 California Recall Election strained California’s direct democracy. In recent California politics there has not been a statewide election conducted on such short notice; county election officials were informed on July 24 that the election would be held on October 7. Nor has California recently seen a ballot with so many candidates running for a single statewide office (see Mueller 1970). Under easy ballot access requirements, Secretary of State Kevin Shelley certified 135 candidates for the official ballot on August 13^1. In the recall, voters cast votes on (1) whether to recall Governor Davis from office, and (2) his possible successor. These two voting decisions were made independent by the federal district court’s decision on July 29. The court’s decision invalidated a state law requiring a vote on the recall question in order for a vote on the successor election to be counted (Partnoy et al. 2003). The abbreviated election calendar also led to many improvisations, including a dramatically reduced number of precinct poll sites throughout the state and the unprecedented ability of military personnel, their dependents, and civilians living overseas to return their absentee ballots by fax. These problems produced litigation and speculation that substantial problems would mar the election and throw the outcome of both the recall and a possible successor’s election into doubt. In the end, the litigation failed to stall the recall election, and the large final vote margins on both the recall question and the successor ballot seemingly overwhelmed Election Day problems. In this paper, we concentrate on some of the problems produced by the complexity of the recall election, but we do not attempt an exhaustive presentation of these problems. We focus on polling place problems on election day, the problems associated with translating the complicated recall election ballot into six languages, how the long ballot influenced voter behavior, and voter difficulties with the ballot measured with survey data. We conclude with a short discussion of the possible impact of these problems on the recall election

    Revisiting the parameterization of potential evaporation as a driver of long-term water balance trends

    Get PDF
    We examine the effects of two different parameterizations of potential evaporation on long-term trends in soil moisture, evaporative flux and runoff simulated by the water balance model underlying the Palmer Drought Severity Index. The first, traditiona

    Intracontinental deformation in southern Africa during the late Cretaceous

    Get PDF
    Intracontinental deformation accommodated along major lithospheric scale shear zone systems and within associated extensional basins has been well documented within West, Central and East Africa during the Late Cretaceous. The nature of this deformation has been established by studies of the tectonic architecture of sedimentary basins preserved in this part of Africa. In southern Africa, where the post break-up history has been dominated by major erosion, little evidence for post-break-up tectonics has been preserved in the onshore geology. Here we present the results of 38 new apatite fission track analyses from the Damara region of northern Namibia and integrate these new data with our previous results that were focused on specific regions or sections only to comprehensively document the thermo-tectonic history of this region since continental break-up in the Early Cretaceous. The apatite fission track ages range from 449 ± 20 Ma to 59 ± 3 Ma, with mean confined track lengths between 14.61 ± 0.1 μm (SD 0.95 μm) to 10.83 ± 0.33 μm (SD 2.84 μm). The youngest ages (c. 80-60 Ma) yield the shortest mean track lengths, and combined with their spatial distribution, indicate major cooling during the latest Cretaceous. A simple numerical thermal model is used to demonstrate that this cooling is consistent with the combined effects of heating caused by magmatic underplating, related to the Etendeka continental flood volcanism associated with rifting and the opening of the South Atlantic, and enhanced erosion caused by major reactivation of major lithospheric structures within southern Africa during a key period of plate kinematic change that occurred in the South Atlantic and SW Indian ocean basins between 87-56 Ma. This phase of intraplate tectonism in northern Namibia, focused in discrete structurally defined zones, is coeval with similar phases elsewhere in Africa and suggests some form of trans-continental linkage between these lithospheric zones
    corecore