1,394 research outputs found
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
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
Futures studies for the southern African region : ‘from Africa’ not ‘on Africa’
Futures studies is well established in the Nordic region and its history can be readily charted, but in Africa it barely exists in an institutional form and its evolution and impact is little known or understood. The first two sections of our paper briefly examine the history of futures studies, spending most attention on the African experience. We go on to show that the Higher Education landscape in the Southern African Development Community (SADC) region is very different to that in the Nordic region. Recent futures reports present forecasts and scenarios that show a differentiated Higher Education landscape in the SADC; there are few Higher Education Institutions (HEIs) and even the most optimistic forecasts show that the region as a whole will not meet the international enrollment norm of 30% by 2050. The last part of the paper examines our experience of collaboration with Finland and its well developed linkages between state and Universities. One outcome of three years of collaboration from 2007 to 2009 between two SANORD members, the Finland Futures Research Centre (now a part of the University of Turku) and Rhodes University, was a proposal to develop a multi-disciplinary, inter-institutional futures studies program intended to help Africa find its own voice in futures studies. The final part of our presentation reflects on the unsuccessful experiences that we have had to date in finding funding. We conclude by asking whether our experience can be seen as highlighting some of the challenges SANORD may be positioned to overcome if the SADC region’s HEIs are to achieve the Knowledge Village scenario and begin to match their Nordic counterparts
Water resources in Botswana with particular reference to the savanna regions
Production and development in the savanna regions of southern Africa are primarily determined by interactions between the limitations imposed by ecological determinants (such as rainfall and soil quality) and the management strategies of the specific region. Good planning, focussing on both the short and long-term effects of water use, is needed in water management strategies. Botswana is already experiencing so-called 'water stress' which is related to a number of factors such as rapidly increasing population leading to a sharp increase in water demand, low and variable rainfall, high rates of evaporation, and the high cost of exploiting existing water resources. At the current rates of abstraction, the lifetime of surface and groundwater resources is limited to decades. Botswana shares four river basins with its neighbouring countries. This results in a situation where 94% of the fresh water resources which Botswana can theoretically access originates outside its borders, making water resource management highly complex. Transnational sharing and management of water resources, therefore, plays a major role in securing sustainability of this precious resource
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
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
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
'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
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