1,133 research outputs found
Vegetation controls on channel stability in the Bell River, Eastern Cape, South Africa
Channel instability has occurred in the Bell River in the form of meander cutoffs, a number of which have occurred since 1952. Increased sediment loading from widespread gully erosion in the catchment has been proposed as the trigger for this instability. Willow species of the Salix family, in particular S. caprea, have been planted along the banks in an effort to prevent further channel shifting. This study reports the results of an investigation into the effect of vegetation on channel form and stability over a 17 km stretch of channel. Results indicate that riparian vegetation has significant effects on channel form which have implications for channel stability. Riparian vegetation increases bank stability and reduces channel cross-sectional area, thereby inducing stability at flows less than bankfull. Evidence indicates that narrow stable stretches are associated with relatively high levels of riparian vegetation. Wider, unstable channels are associated with relatively less riparian vegetation. The effectiveness of riparian vegetation relative to bank sediments was investigated. A dense growth of willows was found to have an equivalent effect to banks with a silt-clay ratio of about 70 per cent. The channel narrowing induced by vegetation may contribute to channel shifting at high flows. The reduced channel capacity is thought to result in more frequent overbank flooding which may ultimately lead to channel avulsion. Thus where increased sediment loading is pushing the channel towards instability, vegetation may be effective in imparting local stability, but it is unable to prevent long-term channel shifts, and may rather help to push the system towards more frequent avulsions
Hydroclimatic trends, sediment sources and geomorphic response in the Bell River catchment, eastern Cape Drakensberg, South Africa
The Bell River in the Eastern Cape Drakensberg of South Africa has shown recent signs of channel instability as evidenced by avulsion, sinuosity reductions, gradient steepening and general channel instability. Analysis of rainfall data did not provide evidence for progressive long term change in rainfall pattern for the catchment. However, annual and seasonal rainfall cycles with variance peaks every 16-19 years were found, from which it can be inferred that flood events following years of below average rainfall may cross the threshold limit for channel stability. Channel instability is often followed by a major flood event after sustained low rainfall periods, a sequence referred to as the Flood and Drought Dominated Regimes by Warner (1987). Evidence presented also indicates an increase in catchment erosion in the past century with attendant sediment production increases to the channel. This may be due to catchment land use and management practices (following settlement by commercial farmers) superimposed on long term climatic changes. The conclusions are that catchment and channel processes are inseparable, and that disequilibrium in the catchment will be transferred to the channel
The Journal of the Friends' Historical Society volume 1, no. 1
1. Foreword
2. Notes and Queries
3. The Handwriting of George Fox (illustrated) By Isaac Sharp, B.A.
4. Grangerised Books By The Editors
5. Our Recording Clerks: I. Ellis HookesBy Norman Penney
6. The Case of William Gibson (illustrated) By The Editor
7. Two Quotations in the London Y.M. Epistle, 1903 By The Editors
8. The Quaker Family of Owen I By Joseph J. Green
9. Letters of Wm. Dewsbury and John Whitehead By The Editors
10. Friends' Reference Library, Devonshire House
11. Book Notes By Norman Penney
12. List of Member
Vegetation controls on channel stability in the Bell River, Eastern Cape, South Africa
Channel instability has occurred in the Bell River in the form of meander cutoffs, a number of which have occurred since 1952. Increased sediment loading from widespread gully erosion in the catchment has been proposed as the trigger for this instability. Willow species of the Salix family, in particular S. caprea, have been planted along the banks in an effort to prevent further channel shifting. This study reports the results of an investigation into the effect of vegetation on channel form and stability over a 17 km stretch of channel. Results indicate that riparian vegetation has significant effects on channel form which have implications for channel stability. Riparian vegetation increases bank stability and reduces channel cross-sectional area, thereby inducing stability at flows less than bankfull. Evidence indicates that narrow stable stretches are associated with relatively high levels of riparian vegetation. Wider, unstable channels are associated with relatively less riparian vegetation. The effectiveness of riparian vegetation relative to bank sediments was investigated. A dense growth of willows was found to have an equivalent effect to banks with a silt-clay ratio of about 70 per cent. The channel narrowing induced by vegetation may contribute to channel shifting at high flows. The reduced channel capacity is thought to result in more frequent overbank flooding which may ultimately lead to channel avulsion. Thus where increased sediment loading is pushing the channel towards instability, vegetation may be effective in imparting local stability, but it is unable to prevent long-term channel shifts, and may rather help to push the system towards more frequent avulsions
Transformation of animal agriculture should be evidence-driven and respectful of livestock's benefits and contextual aspects
FL acknowledges financial support of the Research Council of the Vrije Universiteit Brussel, including the SRP7 and IOF342 projects, and in particular the Interdisciplinary Research Program ââTradition and naturalness of animal products within a societal context of changeâ (IRP11). PM acknowledges financial support of the Helsinki Institute of Sustainability (HELSUS) through the project ââUnderstanding pastoralism sustainability through an interdisciplinary lensâ, of an Ikerbasque Fellowship, and of the BERC 2022-24 programme of the Basque Government. PG and FL acknowledge financial support of the project ââGrazing for environmental and human healthâ funded by the New Zealand Royal Societyâs Catalyst Seeding Fund. SvV reports grant support from USDANIFA( 2020-38640-31521; 2021-38640-34714; 2021-67034- 35118), the Turner Institute of Ecoagriculture, the Bionutrient Institute, and the Greenacres Foundation for projects that link agricultural production systems (including livestock and crops) to the nutritional/metabolite composition of foods and human health. SvV reports prior grant support from the North Dakota Beef Commission for a study on unprocessed and ultra-processed foods, and the Dixon Water Foundation on pasture-based grazing systems
The Journal of the Friends' Historical Society vol. 1 No. 3
1. Notices.
2. Notes and Queries.
3. First Publishers of Truth.
4. Edmund Peckover's Travels in North America and Barbados.
5. Quaker or Common Beggars.
6. County Tipperary Friends Records I.
7. The Quaker Family of Owen III.
8. Inscriptions in Friends' Burial Ground, Bowcroft, near Sheffield.
9. Notes on Friends in South of Scotland II.
10. Editors Proposals.
11. Samuel Bownas to James Wilson, 1751.
12. Friends' Library, Philadelphia, Pennsylvania.
13. Friends' Historical Society of America.
14. Friends' Reference Library.
15. Awbrey of Brecknockshire.
16. Paragraph of the Will of John Rutty, 1770.
17. Third List of Members.
18. Index to Volume 1
'White knuckle care work' : violence, gender and new public management in the voluntary sector
Drawing on comparative data from Canada and Scotland, this article explores reasons why violence is tolerated in non-profit care settings. This article will provide insights into how workers' orientations to work, the desire to care and the intrinsic rewards from working in a non-profit context interact with the organization of work and managerially constructed workplace norms and cultures (Burawoy, 1979) to offset the tensions in an environment characterized by scarce resources and poor working conditions. This article will also outline how the same environment of scarce resources causes strains in management's efforts to establish such cultures. Working with highly excluded service users with problems that do not respond to easy interventions, workers find themselves working at the edge of their endurance, hanging on by their fingernails, and beginning to participate in various forms of resistance; suggesting that even among the most highly committed, 'white knuckle care' may be unsustainable
Tracking the reflexivity of the (dis)engaged citizen: some methodological reflections
The relationship between governments and citizens in many contemporary democracies is haunted by uncertainty and sociologists face the task of listening effectively to citizensâ own reflections on this uncertain relationship. This article reflects on the qualitative methodology of a recently completed UK project which used a combination of diary and multiple interviews/ focus groups to track over a fieldwork period of up to a year citizensâ reflections on their relationship to a public world and the contribution to this of their media consumption. In particular, the article considers how the projectâs multiple methods enabled multiple angles on the inevitable artificiality and performative dimension of the diary process, resulting in rich data on peopleâs complex reflections on the uncertain position of the contemporary citizen
Assessment and Student Learning â a fundamental relationship and the role of information and communication technologies
This paper reviews the role of assessment in student learning and its relationship with the use of information and communication technologies (ICT). There is ample evidence of technology-led innovations failing to achieve the transformations expected by educators. We draw upon existing research to illustrate the links between aspects of student learning, assessment practices and the use of ICT. Assessment influences not only what parts of a course get studied, but also how those parts are studied. While the adoption of ICT does not, in itself, change student behaviours, appropriately designed assessment that exploits the potential of ICT can change studentsâ approaches to learning. We argue that ICT can enable important learning outcomes to be achieved, but these must be underpinned by an assessment strategy that cues students to adopt a suitable approach to learning
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