Browsing by Subject "Okavango delta"
Now showing items 1-11 of 11
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Wolski, P.; Masaka, T.; Raditsebe, L.; Murry-Hudson, M. (Botswana Society, NaN, 2005)[more][less]
Abstract: Seasonal changes in inundation area and peak flood occurrence in the Okavango Delta are analysed using a multiple regression technique. The multiple regression models developed constitute useful and simple tools for predicting inundation area and peak flood occurrence in the Okavango Delta. The regression model for monthly inundation area achieves a coefficient of determination of 0.80 and standard error of 538 km². Explanatory variables in the model are various expressions of long-term and short-term antecedent rainfall and inflow conditions. The model for flood peak occurrence can be used for accurate predictions only in the Jao-Boro distributary, for which it achieves a coefficient of determination of 0.85 and standard error of 15 days, with distance to Delta inlet and an expression of flood size as explanatory variables. Propagation of the flood in the two other analysed distributaries, Maunachira-Khwai and Mboroga-Santantadibe, is complex and its quantitative description appears to be beyond the capacity of a simple regression approach. Additionally, the analyses presented provide insight into the role of storage in the dynamics of flood in the system: hydrological inputs are accommodated in the large system storage, and hydrological response is strongly dependent on the factors affecting (slow!) release from that storage. Based on the analyses, the classic model of kinematic flood wave propagation has been adapted accordingly. URI: http://hdl.handle.net/10311/954 Files in this item: 1
Wolski 2005 Aspects of sea.pdf (2.080Mb) -
VanderPost, C. (Botswana Society, http://www.botsoc.org.bw, NaN, 2005)[more][less]
Abstract: During the years 1849 to 1900 the first maps of (portions of) the Okavango Delta region in Ngamiland were produced by missionaries, explorers, travellers and adventurers. Considerable progress was made from the first attempt by Livingstone and Oswell in 1849 to the work by Passarge at the turn of the 20th century. There were great improvements in the positional accuracy of Lake Ngami, the initial attraction of the region, and many of the river courses and other features in the Okavango-Ngamiland region, as maps became much more detailed. This paper describes the progress from the first rather inaccurate mapping attempts to the more sophisticated work produced just before the turn of the 20th century when the word ‘Okavango’ actually began to appear on maps. These early mapping efforts laid the foundation for the cartography of the colonial era. URI: http://hdl.handle.net/10311/955 Files in this item: 1
VanderPost 2005 Early maps.pdf (2.241Mb) -
Gumbricht, T.; Wolski, P.; Frost, P.; McCarthy, T.S. (Elsevier http://www.doi:10.1016/j.jhydrol.2003.11.010, NaN, 2004)[more][less]
Abstract: The pristine Okavango Delta wetland of northern Botswana is potentially under threat due to water abstraction from its tributaries. We have developed a statistical model which makes it possible to predict the extent of wetland loss which will arise from water abstraction. The model also permits prediction of the maximum area of flooding, and its spatial distribution, three months in advance of the flood maximum. The model was calibrated using maximum areas of seasonal inundation extracted from satellite imagery covering the period 1985–2000, which were correlated with rainfall and total flood discharge. A technique was developed to translate the modelled flood area into a flood map. The methodology can predict maximum area of flooding and its distribution with better than 90% accuracy. An important, although relatively minor, source of error in the spatial distribution of the flood arises from a secular change in flood distribution in the distal Delta which has taken place over the last 15 years. Reconstruction of flooding history back to 1934 suggests that the Delta may be subject to a quasi 80 year climatic oscillation. If this oscillation continues, the extent of flooding will increase in the coming decades. URI: http://hdl.handle.net/10311/428 Files in this item: 1
Gumbricht_JH_2004.pdf (1.267Mb) -
Gumbricht, T.; Wolski, P.; Frost, P.; McCarthy, T.S. (Elservier, www.elsevier.com, NaN, 2004)[more][less]
Abstract: The pristine Okavango Delta wetland of northern Botswana is potentially under threat due to water abstraction from its tributaries. We have developed a statistical model which makes it possible to predict the extent of wetland loss which will arise from water abstraction. The model also permits prediction of the maximum area of flooding, and its spatial distribution, three months in advance of the flood maximum. The model was calibrated using maximum areas of seasonal inundation extracted from satellite imagery covering the period 1985-2000, which were correlated with rainfall and total flood discharge. A technique was developed to translate the modelled flood area into a flood map. The methodology can predict maximum area of flooding and its distribution with better than 90% accuracy. An important, although relatively minor, source of error in the spatial distribution of the flood arises from a secular change in flood distribution in the distal Delta which has taken place over the last 15 years. Reconstruction of flooding history back to 1934 suggests that the Delta may be subject to a quasi 80 year climatic oscillation. If this oscillation continues, the extent of flooding will increase in the coining decades. URI: http://hdl.handle.net/10311/948 Files in this item: 1
Gumbricht JOH 2004.pdf (2.449Mb) -
Magole, L.; Thapelo, K. (Botswana Society, NaN, 2005)[more][less]
Abstract: This paper presents the results of a study carried out on the impact of the recent (2004) severe flooding of the Okavango River on the livelihood of the molapo (flood recession) farming community of Tubu village in Ngamiland sub-district. Government and NGO disaster relief organisations responded to the floods in panic and desperation while affected communities appeared calm and laid-back. To the extent that they (communities) refused to evacuate flood plains and island settlements to make way for the considerably high and potentially dangerous flood of 2004; the communities' reaction was surprising as the floods were so severe upstream, that they caused damage to property, threatened lives and reduced yields significantly. However, studying the farming community of Tubu revealed that community members have other considerations which make them perceive the inherent risk differently from outsiders. Communities view flooding (whether severe or normal) more as part of the biodiversity production system and a source of livelihood than a destructive force. It was found regarding molapo farming that, first, even under hazardous flooding conditions crop yields are still better compared to those under alternative dryland farming. Secondly, destructive floods occur at 10- to 20-year intervals, making the gamble worthwhile because over time the flood-related benefits outweigh the risks. Thirdly, because the molapo farming communities are poor, other sources of livelihood are not adequately developed to take over from molapo farming. Fourth, the system has evolved into an old tradition which the farmers are not willing to part with. Hence the farmers are adamant that abandoning the production system is not, as yet, an option for them. URI: http://hdl.handle.net/10311/949 Files in this item: 1
Magole 2005 Impact of.pdf (1.900Mb) -
Wolski, P.; Murry-Hudson, M.; Fernkvist, P.; Liden, A.; Huntsman-Mapila, P.; Ramberg, L. (Botswana Society, NaN, 2005)[more][less]
Abstract: Groundwater under islands in the Okavango Delta is a known sink of inorganic dissolved minerals, preventing salinisation of this virtually enclosed evaporation-dominated hydrological system. The Okavango Delta is an oligotrophic, yet very productive system, and it is important to understand sources, pathways and recycling of nutrients in order to fully comprehend its ecology. In order to investigate the role of islands as nutrient sinks, concentrations of nitrogen and phosphorus, as well as major inorganic ions were measured in island and floodplain groundwater. The electrical conductivity was found to be up to 50 times higher in the island centre groundwater than in the surrounding floodplain groundwater. The amount of total phosphorus was found to be up to 400 times higher and total nitrogen up to five times higher in the interior of the island than in the surrounding floodplain. These show that major nutrients are, like other inorganic ions, accumulated under islands. Importantly, the ratio of nitrogen to phosphorus was 5:1 in floodplain water and water in island fringe soils, but 1:4 in island centres. his indicates an intensive removal of nitrogen along the floodplain-island groundwater flow path by the floodplain fringe and riparian biota, resulting in a relative enrichment in P. URI: http://hdl.handle.net/10311/950 Files in this item: 1
Wolski 2005 Islands.pdf (1.469Mb) -
VanderPost, C.; Ringrose, S.; Seely, M. (Botswana Society, NaN, 2005)[more][less]
Abstract: Image processing in the upper Okavango catchment resulted in ten generalised classes which may be used as base line data for monitoring future overall land-use/cover change assessments over the entire upper catchment. Specific work was undertaken using single images for more detailed land-use/cover mapping in a 10 km buffer along all tributaries of the upper Okavango in Angola and Namibia. In terms of the under-developed Angolan upper catchment there is relatively little land clearing at present, and impacts on water use and quality are expected to be minimal in the near future. This is a consequence of 20 years of civil war, while the return of refugees is being inhibited by the prevalence of land-mines. Much more extensive development is taking place in Namibia along the southern bank of the Kavango river. This area is likely to become more intensively used as Namibia attempts to develop greater food security. Further work is required to monitor the impacts from Namibian agricultural expansion. These are likely to be pervasive in terms of the ecology of both the Mahango Game Reserve in Namibia and the Okavango Delta in Botswana. URI: http://hdl.handle.net/10311/936 Files in this item: 1
VanderPost 2005 Prelim.pdf (2.370Mb) -
Mosepele, K.; Mosepele, B.; Williams, L. (Botswana Society, NaN, 2005)[more][less]
Abstract: This study investigates the feeding ecology of Schilbe intermedius across its entire life history. Data were collected using experimental fishing nets in two habitats in a seasonal floodplain. The results showed that S. intermedius has an ontogenetic shift in feeding behaviour where the young fish are primarily generalist predators, feeding on aquatic invertebrates while the older fish are more specialised predators feeding primarily on fish. This study showed that there is a higher potential for intra-specific competition among the older fish than in the younger size classes. However, it was recognized that this study is a snap-shot of the feeding ecology of S. intermedius and that a longer time series study is needed to study its feeding ecology. URI: http://hdl.handle.net/10311/940 Files in this item: 1
Mosepele 2005 Prelim.pdf (1.295Mb) -
Mbaiwa, J.E. (John Wiley and Sons, http://www.wiley.com, NaN, 2004)[more][less]
Abstract: This paper uses the concept of sustainable rural livelihoods and income diversification to assess the role that basket making as a cultural tourism activity can play in improving rural livelihoods in the Okavango Delta, Botswana. Using both primary and secondary data sources, this paper points out that shocks and natural causes such as drought, disease and changing flood levels in the Okavango River, particularly the drying of the Thaoge (one of the distributaries of the Okavango), have contributed to a decline in livestock and crop yields and increased poverty levels in the region. Therefore, alternative livelihood options that can diversify rural incomes from agricultural production need to be identified. This paper argues that basket making has the potential to diversify rural incomes and improve livelihoods in the Okavango. Baskets are a cultural tourism product that can raise income earning and employment opportunities for rural residents in the Okavango. For this to be successful, basket making will need to be developed as part of cultural tourism. A sustainable cultural tourism sector where baskets are key products requires the sustainable use of natural resources used for basket making. These resources are at present overharvested and are threatened with depletion. There is also a need to promote the empowerment of basket weavers particularly in entrepreneurship and managerial skills in the tourism business, attract young and educated people and promote the preservation of traditional basket making skills, which are important in the development of cultural tourism. URI: http://hdl.handle.net/10311/935 Files in this item: 1
Mbaiwa 2004 Int Journ Tourism.pdf (3.700Mb) -
Mbaiwa, J.E. (Routledge, http://www.informaworld.com, NaN, 2004)[more][less]
Abstract: The objective of this article is to assess the socio-cultural impacts of tourism development in the Okavango Delta, Botswana. This paper largely relied on the research work and reports by the author in the Okavango Delta from 1998 to 2004. In all instances, both primary and secondary data sources were used. However, much of the paper is based on the results of a survey carried out between April 2001 and July 2002. Findings indicate that tourism development in the Okavango Delta has both positive and negative socio-cultural impacts. Some of the positive socio-cultural impacts include income generation and employment opportunities from both community-based tourism projects and safari companies, infrastructure development such as airport and airstrips, tarred roads, hotels, lodges and camps, the improvement of social services such as banking, health, telecommunications and access to electricity. The negative socio-cultural impacts include enclave tourism, racism, relocation of traditional communities, breaking up of the traditional family structure, increase in crime, prostitution, the adoption of the Western safari style of dressing and a traditionally unacceptable ‘vulgar’ language by young people. This article argues that tourism needs to be sensitive to local cultural norms and beliefs for it to be accepted by local people and promote sustainable development. This is possible if all the stakeholders (government, operators and local people) collaborate in policy formulation, implementation and monitoring. This can minimise the negative cultural impacts and instead promote the positive. URI: http://hdl.handle.net/10311/946 Files in this item: 1
Mbaiwa 2004 Tourism Culture.pdf (4.520Mb) -
Masamba, W.R.L.; Muzila, A. (Botswana Society, NaN, 2005)[more][less]
Abstract: The concentration of the metal ions Na, K, Ca, Mg, Zn, Cu, Mn, Co, Fe, Cr, Ni, and Pb were determined in water samples of the Okavango Delta’s panhandle - Maunachira-Khwai water system during periods of high (June 2004) and low (November 2004) water flow. The concentrations of Na (1.67 to 12.77 mg/L), K (1.37 to 5.80 mg/L), Ca (2.46 to 6.98 mg/L) and Mg (0.69 to 2.83 mg/L) increased with distance from Mohembo indicating concentration of these metal ions by evaporation. Cu (up to 0.028 mg/l), Co (up to 0.053 mg /L), Fe (0.010 to 0.60 mg/L), Ni (up to 0.052mg/L), Mn (up to 0.044 mg/L) and Pb (0.017 to 0.28 mg/L) generally decreased in concentration with increase in distance from Mohembo, indicating that the Delta acts as a filter for these ions. Zn (0.049 to 0.101 mg/L) had lower concentrations at Mohembo than the other sampling sites, indicating solubilisation of previously deposited metals ions, or presence of Zn within the Delta. Chromium was not detected except at Seronga (0.026 mg/L) during periods of high water flow. URI: http://hdl.handle.net/10311/951 Files in this item: 1
Masamba 2005 Spatial.pdf (2.281Mb)
Now showing items 1-11 of 11