Controls on river terrace formation in New Zealand

[EUS] Artikulu honek, argitaratutako bibliografiaren bidez, Zeelanda Berriko ibai-terrazen garapenari eragiten dieten agente morfogenetikoak aztertzen ditu. Erreferentzia gisa Ipar Irlako 4 kasu eta Hego Irlako 3 kasu erabili dira. Oro har, ibai-terrazak sortzeko orduan, klima, sedimentuen erabilgarritasunan eta prezipitazioan duen eraginaren bitartez, eragile nagusiena da. Altxaketa tektonikoak forma hauen kontserbazioa eragiten du. Hainbat kasutan, gertaera asaldatzaileen ondorioz sortutako sedimentu kopuru handiek, fase morfogenetiko desberdinak eragin dituzte lokal/erregional mailan, nazional/kontinental mailan beharrean. Gertaera asaldatzaileen artean, besteak beste, ekarpen bolkaniko naturalak eta gizakiok bultzatutako lur erabilera aldaketen ondorioz sortutako sedimentu ekarpenak barneratzen dira.[ES] Este artículo analiza los agentes morfogenéticos de las terrazas fluviales en Nueva Zelanda mediante una revisión selectiva de la bibliografía existente. Se han tomado como referencia 4 casos localizados en la Isla del Norte y otros 3 en la Isla del Sur. En términos generales, el control climático sobre la disponibilidad de sedimentos y las precipitaciones ejerce la principal influencia en la génesis de las terrazas fluviales. La conservación de estas formas está influida por el levantamiento tectónico. En ciertos casos, grandes aportaciones de sedimentos generados como consecuencia de eventos perturbadores han provocado diferentes fases morfogenéticas a escala local/regional en lugar de a escala nacional/continental. Ejemplos de estos eventos incluyen aportaciones volcánicas naturales y sedimentarias generadas por la acción del hombre como consecuencia de cambios en los usos del suelo.[EN] This paper analyses controls on river terrace formation in New Zealand through a selective review of published literature. Emphasis is placed on four case studies from the North Island and three case studies from the South Island. In general terms, climatic controls upon sediment availability and discharge exert the primary influence on terrace formation. The preservation of terraces is influenced by tectonic uplift. In some instances, large inputs of sediment in response to disturbance events have induced differing phases of terrace formation at a local/regional rather than a national/continental scale. Examples of disturbance events include ‘natural’ volcanic inputs and human-induced sediment inputs in response to land use changes

Let the Rivers Speak: thinking about waterways in Aotearoa New Zealand

This article explores deep underlying assumptions about relationships between people and the planet, and how these translate into very different ways of relating to waterways in Aotearoa New Zealand. In te ao Mäori – ancestral Mäori ways of living – rivers and lakes are the tears of Ranginui, the sky father, mourning his separation from Papatüänuku, the earth mother, and people are their descendants, joined in complex whakapapa that link all forms of life together. In modern ways of thinking, on the other hand, ideas such as private property, resource management and ecosystem services can be traced back to the Genesis story of God’s gift of ‘dominion’ to Adam and Eve over fish, birds, plants and the earth itself, including waterways, in which all other life forms are created for human purposes. In successive Waitangi Tribunal claims, iwi have disputed these assumptions in relation to fisheries, tribal lands and rivers, and, in worldleading legislation, the Whanganui River has been declared a legal person with its own rights. In this article, the authors discuss different ways in which the rights of rivers as rivers might be understood in scientific terms, investigating the ‘geomorphic rights’ of the Whanganui River, for instance, and how rivers as living communities of land, water, plants, animals and people might be understood through ‘river ethnography’, an approach that aligns a wide range of natural and social sciences with mätauranga taiao – ancestral knowledge of other living systems. They also consider how current policy discussions might be informed by such framings, so that river communities across Aotearoa New Zealand may be restored to a state of ora – life, health, abundance and prosperity

Grassland Resources and Protections in the Yellow River Source Zone on the Qinghai-Tibet Plateau

This paper summarises resources and protections of the Yellow River Source Zone on the Qinghai-Tibet Plateau. A concerted effort has been made to address concerns for overgrazing on the alpine steppe and alpine meadow landscapes in the source zone of the Yellow River. An assessment of the impacts of overgrazing includes consideration of the role of small mammals (on the one hand they are considered as a critical ecosystem engineer, on the other they are perceived as a major threatening pest). Analyzed in this paper are management options in the restoration of degraded grasslands

Mapping Valley Bottom Confinement at the Network Scale

In this article, we demonstrate the application of a continuous confinement metric across entire river networks. Confinement is a useful metric for characterizing and discriminating valley setting. At the reach scale, valley bottom confinement is measured and quantified as the ratio of the length of channel confined on either bank by a confining margin divided by the reach length. The valley bottom is occupied by the contemporary floodplain and/or its channel(s); confining margins can be any landform or feature that makes up the valley bottom margin, such as bedrock hillslopes, terraces, fans, or anthropogenic features such as stopbanks or constructed levees. To test the reliability of calculating confinement across entire networks, we applied our geoprocessing scripts across four physiographically distinct watersheds of the Pacific Northwest, USA using freely available national datasets. Comparison of manually digitized and mapped with modeled calculations of confinement revealed that roughly one‐third of reaches were equivalent and about two‐thirds of the sites differ by less than ±15%. A sensitivity analysis found that a 500 m reach segmentation length produced reasonable agreement with manual, categorical, expert‐derived analysis of confinement. Confinement accuracy can be improved (c. 4% to 17% gains) using a more accurately mapped valley bottom and channel position (i.e. with higher‐resolution model inputs). This is particularly important when differentiating rivers in the partly confined valley setting. However, at the watershed scale, patterns derived from mapping confinement are not fundamentally different, making this a reasonably accurate and rapid technique for analysis and measurement of confinement across broad spatial extents

The dark art of interpretation in geomorphology

The process of interpretation, and the ways in which knowledge builds upon interpretations, has profound implications in scientific and managerial terms. Despite the significance of these issues, geomorphologists typically give scant regard to such deliberations. Geomorphology is not a linear, cause-and-effect science. Inherent complexities and uncertainties prompt perceptions of the process of interpretation in geomorphology as a frustrating form of witchcraft or wizardry – a dark art. Alternatively, acknowledging such challenges recognises the fun to be had in puzzle-solving encounters that apply abductive reasoning to make sense of physical landscapes, seeking to generate knowledge with a reliable evidence base. Carefully crafted approaches to interpretation relate generalised understandings derived from analysis of raw data with field observations/measurements and local knowledge to support appropriately contextualised place-based applications. In this paper we develop a cognitive approach (Describe-Explain-Predict) to interpret landscapes. Explanation builds upon meaningful description, thereby supporting reliable predictions, in a multiple lines of evidence approach. Interpretation transforms data into knowledge to provide evidence that supports a particular argument. Examples from fluvial geomorphology demonstrate the data-interpretation-knowledge sequence used to analyse river character, behaviour and evolution. Although Big Data and machine learning applications present enormous potential to transform geomorphology into a data-rich, increasingly predictive science, we outline inherent dangers in allowing prescriptive and synthetic tools to do the thinking, as interpreting local differences is an important element of geomorphic enquiry

The Blurred Line Between Form and Process: A Comparison of Stream Channel Classification Frameworks

Stream classification provides a means to understand the diversity and distribution of channels and floodplains that occur across a landscape while identifying links between geomorphic form and process. Accordingly, stream classification is frequently employed as a watershed planning, management, and restoration tool. At the same time, there has been intense debate and criticism of particular frameworks, on the grounds that these frameworks classify stream reaches based largely on their physical form, rather than direct measurements of their component hydrogeomorphic processes. Despite this debate surrounding stream classifications, and their ongoing use in watershed management, direct comparisons of channel classification frameworks are rare. Here we implement four stream classification frameworks and explore the degree to which each make inferences about hydrogeomorphic process from channel form within the Middle Fork John Day Basin, a watershed of high conservation interest within the Columbia River Basin, U.S.A. We compare the results of the River Styles Framework, Natural Channel Classification, Rosgen Classification System, and a channel form-based statistical classification at 33 field-monitored sites. We found that the four frameworks consistently classified reach types into similar groups based on each reach or segment’s dominant hydrogeomorphic elements. Where classified channel types diverged, differences could be attributed to the (a) spatial scale of input data used, (b) the requisite metrics and their order in completing a framework’s decision tree and/or, (c) whether the framework attempts to classify current or historic channel form. Divergence in framework agreement was also observed at reaches where channel planform was decoupled from valley setting. Overall, the relative agreement between frameworks indicates that criticism of individual classifications for their use of form in grouping stream channels may be overstated. These form-based criticisms may also ignore the geomorphic tenet that channel form reflects formative hydrogeomorphic processes across a given landscape

Policy Brief: Making Space for Philippine Rivers

No abstract available

Characterization of Ribosomal Frameshifting in Theiler's Murine Encephalomyelitis Virus.

Theiler's murine encephalomyelitis virus (TMEV) is a member of the genus Cardiovirus in the Picornaviridae, a family of positive-sense single-stranded RNA viruses. Previously, we demonstrated that in the related cardiovirus, Encephalomyocarditis virus, a programmed-1 ribosomal frameshift (1 PRF) occurs at a conserved G_GUU_UUU sequence within the 2B-encoding region of the polyprotein open reading frame (ORF). Here we show that-1 PRF occurs at a similar site during translation of the TMEV genome. In addition, we demonstrate that a predicted 3= RNA stem-loop structure at a noncanonical spacing downstream of the shift site is required for efficient frameshifting in TMEV and that frameshifting also requires virus infection. Mutating the G_GUU_UUU shift site to inhibit frameshifting results in an attenuated virus with reduced growth kinetics and a small-plaque phenotype. Frameshifting in the virus context was found to be extremely efficient at 74 to 82%, which, to our knowledge, is the highest frameshifting efficiency recorded to date for any virus. We propose that highly efficient-1 PRF in TMEV provides a mechanism to escape the confines of equimolar expression normally inherent in the single-polyprotein expression strategy of picornaviruses.Work in the A.E.F. lab is supported by the Wellcome Trust [088789], [106207]; and the Biotechnology and Biological Sciences Research Council [BB/J007072/1]. L.F. is supported by a Biotechnology and Biological Sciences Research Council PhD studentship.This is the final published version. It first appeared at http://jvi.highwire.org/content/early/2015/06/05/JVI.01043-15.abstract

Decision aid on radioactive iodine treatment for early stage papillary thyroid cancer - a randomized controlled trial

Abstract Background Patients with early stage papillary thyroid carcinoma (PTC), are faced with the decision to either to accept or reject adjuvant radioactive iodine (RAI) treatment after thryroidectomy. This decision is often difficult because of conflicting reports of RAI treatment benefit and medical evidence uncertainty due to the lack of long-term randomized controlled trials. Methods We report the protocol for a parallel, 2-arm, randomized trial comparing an intervention group exposed to a computerized decision aid (DA) relative to a control group receiving usual care. The DA explains the options of adjuvant radioactive iodine or no adjuvant radioactive iodine, as well as associated potential benefits, risks, and follow-up implications. Potentially eligible adult PTC patient participants will include: English-speaking individuals who have had recent thyroidectomy, and whose primary tumor was 1 to 4 cm in diameter, with no known metastases to lymph nodes or distant sites, with no other worrisome features, and who have not received RAI treatment for thyroid cancer. We will measure the effect of the DA on the following patient outcomes: a) knowledge about PTC and RAI treatment, b) decisional conflict, c) decisional regret, d) client satisfaction with information received about RAI treatment, and e) the final decision to accept or reject adjuvant RAI treatment and rationale. Discussion This trial will provide evidence of feasibility and efficacy of the use of a computerized DA in explaining complex issues relating to decision making about adjuvant RAI treatment in early stage PTC. Trial registration Clinical Trials.gov Identifier: NCT0108355