Browsing by Subject "water security"

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    Assessing the vulnerability of Gaborone Dam to climate change up to the year 2090 for the purpose of water security in the Greater Gaborone
    (2026) Setswammung, Thusego Sebastian; Wolski, Piotr
    Water forms part of critical infrastructure, and this dissertation covers the impacts of projected climate change on water resources. The primary focus is on climate change's effect on the water balance of the Gaborone Dam. Gaborone Dam forms part of the city of Gaborone's (and surroundings - Greater Gaborone) water supply. The motivation for this study is that Botswana is a landlocked country with present water challenges (scarcity) and hence in need of good water governance, especially for its capital city—Gaborone. Given the projected climate and increase in population, especially in the city, water resources are likely to be even more vulnerable than they are presently. The Gaborone Dam has reached critical levels (low volumes) a few times in the past 20 years, and chances of drier conditions remain for the future. Since water is paramount for sustainable development and its insecurity jeopardises the country's sustainable ambitions and could potentially exacerbate societal inequalities, the water security of the country, and especially the city, has to be assessed as is done in this study. The study used multi-model ensembles of CMIP6 and CORDEX Africa with a focus on SSP24.5/SSP5-8.5 and RCP4.5/RCP8.5 future socio-economic development and scenarios of greenhouse gas emissions, respectively, to assess future rainfall and temperature of the study area—the Gaborone Dam. With historical observed rainfall and temperature values used as a baseline (1991 to 2020), the Gaborone Dam and its catchment's future rainfall and temperature were assessed for near (2031 to 2060) and far (2061 to 2090) future periods. Subsequently, the water balance of the Gaborone Dam was calculated, and a range of possible future water supply deficits were determined. Finally, these results were evaluated in the context of the literature relevant to Gaborone's water security now and in the future. The results indicate that future climate projections encompass a broad range of conditions, suggesting that both increases and decreases in rainfall, and consequently water resources, are possible. Overall, however, coupled with existing literature, there is a higher chance of a decline in available water resources. However, there are uncertainties as this is inherent with modelling future projections—rainfall, temperature and population-driven water demand and use.
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    Exploring the relationship between the water-energy-food nexus and livelihoods at the local scale: a case study focussed on a low-income residential area in Velddrif, South Africa
    (2024) Price, Penelope; Shackleton, Sheona
    The water-energy-food nexus (WEF nexus) has primarily been applied to addressing WEF security at large spatial scales in response to resource scarcity concerns. In contrast, WEF security at local levels, particularly amongst the poor, has received little attention. This thesis addresses this gap by exploring the application of the WEF nexus at the local level through a case study of a low-income residential area in the small urban fishing town of Velddrif on the west coast of South Africa. The primary empirical focus of the study is the household where availability, access, and affordability of WEF resources, as well as the linkages to livelihood options, are explored through a household survey. This is complemented by the gathering of contextual qualitative data on service delivery, livelihood opportunities, and the WEF nexus at the town and municipal scales. The results indicated a low-income settlement with a high degree of water and electricity service delivery, which is rare in the South African context. They also revealed a concentration of employment in the fisheries sector, but very little fishing as a means of household food provision. Households typically relied on supermarkets and corner shops for food provision, indicating a reliance on income or financial capital as opposed to other livelihood capitals. All households reported some form of income, with a low percentage relying solely on social grant income. In line with the provisions of The Constitution, households that register as indigent are supported by the municipality in terms of receiving a minimum allocation of free basic water and electricity. The local municipality ensured their financial viability through imposing mechanisms to collect municipal rates debt before they escalated, thus enabling continued provision of basic services to all residents and free basic services to indigent households. The availability of water has been at risk due to recent drought conditions, and this highlighted the significant consumption of the town's largest employer - the large-scale fish processing factory, which through the industrial production of food is also the town's largest electricity consumer. Urgent scaling back of their water consumption was achieved through the installation of a desalination plant, thus averting employment losses through an alternative solution of reducing or stopping factory production. It did however realise other trade-offs, such as an increase in their electricity consumption. The fish factory therefore emerged as a significant actor in the WEF nexus / livelihoods intersection in this case study. Similarly, the local municipality plays a pivotal role in balancing trade-offs between availability and affordability of water and electricity in seeking to foster employment through economic development, as well as the sustainability of basic service provision. The WEF nexus at this level is therefore very useful in highlighting issues of equity, resource status and governance.
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    The threat to South African water security posed by wastewater-driven eutrophication: a proposal for a new regulatory approach
    (2017) Harding, William Russell; Feris, Loretta
    The quality of South Africa's raw potable water resources is severely impacted by eutrophication (nutrient enrichment). As much as two-thirds of the reservoir impounded resource may be affected. Wastewater effluents and/or the integration of wastewater return flows as part of the water balances of many reservoirs constitute the primary source of this nutrient pollution. South Africa's historical awareness and understanding of the eutrophication threat to surface waters is comparable with that of other, similarly-afflicted, countries. In particular, the need to manage phosphorus was recognised as early as 1962 when South Africa promulgated one of the first (global) regulations for phosphorus in wastewater effluents. More recently, eutrophication has been ranked as a high priority by the the National Water Resource Strategy. Despite this background, phosphorus removal from wastewater effluents in South Africa remains virtually unregulated. Additionally, there is no resource-directed protocol for the accounting of all sources of phosphorus (or other pollutants) at a catchment level, rendering problematic, if not impossible, the fair and equitable allocation of levies on wastewater discharges. This dissertation examines how wastewater-originating eutrophication is regulated in the USA and Europe, with phosphorus as a central focus. A comparative assessment of the equivalent situation in South Africa is provided and the shortcomings of the latter highlighted. As a solution, I suggest an equitable and transparent scheme of pollutant accounting by individual source, ideally suited to the allocation of waste discharge levies. Applied against a specific resource requirement, for example an identified need to reduce phosphorus in a particular reservoir, this approach also provides a legally sound scheme for pollutant load regulation and permitting.