Understanding and quantifying channel transmission loss processes in the Limpopo River Basin
- Authors: Mvandaba, Vuyelwa
- Date: 2018
- Subjects: Water-supply -- Management , Water-supply -- Limpopo River Watershed , Alluvium -- Limpopo River Watershed , Streamflow -- Limpopo River Watershed
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63797 , vital:28490
- Description: Water availability is one of the major societal issues facing the world. The ability to understand and quantify the impact of key hydrological processes on the availability of water resources is therefore integral to ensuring equitable and sustainable resource management. A review of previous hydrological studies conducted in the Limpopo River Basin has revealed a gap in the understanding of surface water-groundwater interactions, particularly channel transmission loss processes. These earlier studies, focused largely on the Limpopo River’s main stem, have attributed the existence of these streamflow losses to the presence of significant alluvial aquifers and indicated that the losses account for about 30 percent (or 1000 Mm3 a-1) of the basin’s water balance. The work conducted in this dissertation reports on the delineation of alluvial aquifers across three sub-basins of the Limpopo River Basin namely, the Mokolo (South Africa), Motloutse (Botswana) and Mzingwane (Zimbabwe) sub-basins and the estimation of potential channel transmission losses based on the alluvial aquifer properties. Additionally, an assessment of the different approaches that can be applied to simulate these channel transmission losses in the Pitman Model is presented. To delineate alluvial aquifers, general land cover classes including alluvial aquifers were produced from Landsat-8 imagery through image classification. The areal extent of the delineated alluvial aquifers was calculated using ArcMap 10.3. To quantify channel transmission losses and determine the effects on regional water resources, three approaches using the Pitman model were applied. The three approaches include an explicit transmission loss function, the use of a wetland function to represent channel-floodplain storage exchanges and the use of a ‘dummy’ reservoir to represent floodplain storage and evapotranspiration losses. Results indicate that all three approaches were able to simulate channel transmission losses, although with differing magnitudes. Observed monthly flow data were used to as a means of validating loss simulations however for each sub-basin, medium and low flows were over-simulated which accounts for water uses that were inefficiently represented due to lack of data. Knowledge of the structure of the transmission loss function dictates that it is better at representing the dynamics of channel transmission losses, as it takes into account the contribution of losses to groundwater recharge whereas the other two functions simply store water and release it back to the channel. Overall, the hydrological modelling results demonstrate the potential of each approach in reproducing the dynamics of channel transmission losses between channel and alluvial aquifer within an existing sub-basin scale hydrological model. It is believed that better quantification of losses and more efficient qualitative determination of the function which best represents transmission losses, can be attained with more reliable observed data. In conclusion, a study of this nature can be beneficial to water resource estimation programmes as it highlights the uncertainties related with quantifying channel transmission loss processes in a semi-arid environment.
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- Date Issued: 2018
The principle of distinction and modern armed conflicts: a critical analysis of the protection regime based on the distinction between civilians and combatants under international humanitarian law
- Authors: Chigowe, Lloyd Tonderai
- Date: 2017
- Subjects: Humanitarian law , Military art and science -- Law and legislation , Combatants and noncombatants (International law) , Military law , National security -- Law and legislation , Private military companies (International law) , Human rights -- International cooperation , Soft law
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10962/4668 , vital:20710
- Description: This thesis interrogates the applicability of the principle of distinction in modern armed conflicts. The distinction between combatants and civilians and between civilian objects and military objectives has become blurred as a result of the changes that have taken place in modern armed conflicts. While the principle of distinction was tailor made to regulate traditional, conventional armed conflicts, an evolution in the nature, means and methods of warfare has made the application of the principle of distinction challenging. One of the challenges that arise as a result of the changes that have taken place in modern armed conflicts include the difficulty of distinguishing civilians and civilian objects, which are entitled to protection under international humanitarian law from combatants and military objectives which are legitimate targets. This has compromised the protection that the law seeks to offer during armed conflicts since civilians and civilian objects have become constant targets. Another challenge is that the involvement of civilian persons in armed conflicts has made it difficult to determine the responsibility of these individuals as well as the states that hire them for violations of international law during armed conflicts. Furthermore, the emergence of new methods of warfare has resulted in many objects and facilities that are traditionally regarded as civilian objects becoming military objectives, thus losing their protection under international humanitarian law. This thesis will use the examples of the involvement of private military and security companies in armed conflicts as well as the emergence of drone and cyber warfare to illustrate these challenges. The study will examine the application of the principle of distinction to the growing practice of outsourcing of military services to Private Military and Security Companies. Firstly, the study will examine the status of PMSC personnel under the principle of distinction, that is whether they qualify as combatants or civilians. The study will then examine the consequences of PMSC personnel’s participation in armed conflicts. Importantly, the study will explore responsibilities of states that hire private military and security personnel, PMSC companies as well as superiors in charge of PMSC personnel for any violation of international law committed by contractors during armed conflicts. The study will also examine the application of the principle of distinction to drone and cyber warfare. The study will examine the status of drone and cyber operators under the principle of distinction as well as the applicability of the principle of distinction between civilian objects and military objectives in drone and cyber warfare. The study will discuss some of the problems that arise as result of the introduction of these new methods of warfare, which makes the application of the principle of distinction to modern armed conflicts challenging. The thesis concludes by arguing that while the principle of distinction remains an indispensable concept of international humanitarian law, it needs to be adapted for it to be applicable to modern armed conflicts. Therefore, suggestions shall be made on how the principle can be adapted to ensure that it remains relevant to modern armed conflicts.
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- Date Issued: 2017
Rhodes University Research Report 2010
- Authors: Rhodes University , Roberts, Jaine
- Date: 2010
- Language: English
- Type: Text
- Identifier: vital:565 , http://hdl.handle.net/10962/d1011968
- Description: From Introduction: In 2010, the total subsidy earning accredited research output count for Rhodes University of 615.3 units represents an increase of 9% on the previous year. By far the major contributor to this growth was the significant increase in both PhD (37.5% up on 2009) and Masters by thesis students (34.5% up on 2009). Rhodes contributed 3.3% of all accredited research output in the public higher education sector in 2010 (0.1% up on 2009). With 1.9% of academic staff in the system, Rhodes retained its place amongst the top three most productive universities as measured by accredited publications per academic. Rhodes exceeds the DHET research output norm for universities by 53%. In 2010, the total accredited publication output count for Rhodes University of 325.33 units represented a decline over 2009 of 7.3 percent. This followed two years of steep growth during which accredited research publication output grew by 28%. Accredited publication output for 2010 consisted mainly of journals at 89.9%, with conference proceedings at 7.2% and books and book chapters at 2.9% making far smaller contributions. This mix is roughly in line with the sector as a whole. It has been recognised that books and book chapters are underappreciated in relation to journals, and recommendations to increase the weighted points that they attract as proposed by ASSAf1 are awaiting approval by the DHET. and book chapters submitted, because the hurdle of independent reviewing is not always met by the publishing avenues chosen by authors. The University has become increasingly reliant on research funding in recent years as a larger proportion of its budget, and attention at university council level is being given to ensuring that appropriate systems and support structures for researchers are in place. I add my warm thanks and congratulations to all of our researchers, funders, collaborators and partners who contributed to the excellent research results of 2010. , A Publication of the Rhodes Research Office,compiled and edited by Jaine Roberts
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- Date Issued: 2010
A view of Herrick's poetic world and its values: with some reference to his fairy poetry
- Authors: Letcher, Valerie Helen
- Date: 1986
- Subjects: Herrick, Robert, 1591-1674 , Fairy poetry, English , English poetry -- History and criticism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2265 , http://hdl.handle.net/10962/d1004773 , Herrick, Robert, 1591-1674 , Fairy poetry, English , English poetry -- History and criticism
- Description: From the preface: Herrick was a prolific poet, and a remarkably consistent one. Hesperides encompasses a lifelong collection of poems on themes as diverse as serious reflections on life's brevity and the playful examination of the minutely imagined world of the fairies, yet his vision of life remains coherent. My purpose in this study is to try to see ·Herrick's secular work in its unity and as a whole, without claiming to consider every aspect of his secular poetry. (I have not attempted, for example, to consider his classical sources.) As my interest lies mainly in his values and vision, my emphasis is on theme and tone, and the way they indicate his conception of life. For this reason, I only occasionally consider Herrick's poetic techniques, such as his versification and language, and there are no detailed analyses of individual poems which examine them from every angle. In addition, I am almost entirely concerned here with Hesperides , the secular poetry, and not with Herrick's religious verse, which is collected under the title of His Noble Numbers. (Although Herrick calls his book Hesperides: or The Works both Humane and Divine, the arrangement within is clearly a division into Hesperides, the secular poetry, and His Noble Numbers, the religious verse.)
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- Date Issued: 1986
A contribution to the biology of Tilapia mossambica Peters in Lake Sibaya, South Africa
- Authors: Bruton, Michael N
- Date: 1973
- Subjects: Cichlids , Tilapia , Mozambique tilapia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5839 , http://hdl.handle.net/10962/d1009950 , Cichlids , Tilapia , Mozambique tilapia
- Description: An account is given of some aspects of the biology of Tilapia mossambica Peters in Lake Sibaya, South Africa. Previous work on Tilapia in Lake Sibaya is reviewed. Apart from brief gillnet surveys, which recorded the species' presence, no research on T. mossambica had been performed at Lake Sibaya before the two-year study of Minshull who collected data on food preferences, depth distribution of juveniles and breeding biology of adults. The main physiographical features of the lake are outlined. Lake Sibaya is a warm shallow coastal lake with extensive shallow terraces in the littoral which shelve abruptly into underwater valleys. The substrate is predominantly sandy. Aquatic macrophytes are generally restricted to water 1-7 m deep. Adult fishes (over 8 cm SL) are usually absent from water deeper than 12 m and shallower than 0.5 m, whereas juveniles may occur at all depths, and fry only in very shallow water. T. mossambica inhabits the littoral in the warm and transition periods (August to April) but moves into deep water in the cool season (May to July). Exposed and sheltered shallow areas are utilised for different purposes by adult fishes, the former for nesting, and the latter for feeding and mouth-brooding. Habitat selection by males was governed by nest site selection. Habitat Nests were most common in sheltered, sparsely vegetated littoral and sublittoral areas, but also present in well-vegetated sheltered areas. Breeding females preferred sheltered littoral areas but ventured onto the terrace to release the young. Juvenile and fry T. mossambica inhabited shallow exposed shores with a temperature gradient which reversed diurnally. The breeding, shoaling and feeding behaviour of T. mossambica is described, and integrated with data on T. mossambica from other systems. The breeding season spans seven months. Shoaling takes place in shallow water probably as a means of protection. T. mossambica is an omnivorous feeder relying largely on diatoms. The main predator is probably the barbel Clarias gariepinus, but avian predators may be more important. A method whereby the time of formation of rings on the scales of T. mossambica is described. The fishes were found to reach maturity after one year at a length of about 8 cm in females, and after two years at 10 cm in males. The breeding population had a standard length mode of 14 cm (females) and 17 cm (males). The maximum final size was about 24 cm SL. An estimate of the standing crop for fishes in the littoral and subiittoral areas of the eastern and southern shores of the south basin is given. The data were derived from a mark and recapture The biology of T. mossambica in Lake Sibaya as revealed by the present study is discussed with reference to data on the same and similar species in other systems. The utilis ation of the available resources in the lake by T. mossambica is commented upon, and reference is made to the significance of stunting, and the import ance of the retention of generalised characters for the successful habitation of the cyclically-renewed habitat of the littoral. Precocious breeding in T. mossambica is regarded as a functional adaptation which increases the proportion of fishes small enough to utilise the rich food resources in shallow water.
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- Date Issued: 1973
A study of the novels of F. Scott Fitzgerald
- Authors: Rodda, Peter
- Date: 1967
- Subjects: Fitzgerald, F. Scott (Francis Scott), 1896-1940 , American literature -- Criticism and interpretation , American fiction -- 20th century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2311 , http://hdl.handle.net/10962/d1013072
- Description: Henry Dan Piper has exploded the legend that all of Fitzgerald' s books where out of print when he died. There may be similar romantic exaggeration which does not bear examination in the popular view that Fitzgerald's reputation as an artist was eclipsed in his later years and magically revived after his death by the editing and publication by Edmund Wilson in 1941 of the unfinished novel Last Tycoon, and of The Crack-Up. Investigation by Matthew J. Bruccoli has shown the essential oversimplification inherent in the widely-held belief that Fitzgerald's last complete novel to be published, Tender is the Night was dismissed or ignored by reviewers demanding novels of social conscience. Fitzgerald attracted legends and since his death has become something of a folk-hero the type of the golden boy who achieved early and instantaneous fame, lives riotously and is then engulfed by the backwash of his own youthful folly somehow leaving an unpublished masterpiece to confound his critics at his early death. Preface, p. 1.
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- Date Issued: 1967