3. Electronic Theses and Dissertations (ETDs) - All submissions
Permanent URI for this communityhttps://wiredspace.wits.ac.za/handle/10539/45
Browse
2 results
Search Results
Item Innovative coupling of hydrological modelling for IWRM: linking catchment functioning with socio-economic conditions in the Olifants(2011-05-12) Magombeyi, Manuel SimbaComputerised integrated models from science contribute to better informed and holistic exante integrated assessments of multifaceted policies and technologies. This view has lead to considerable effort being devoted to developing integrated models to support decisionmaking under Integrated Water Resources Management (IWRM). Nevertheless, an appraisal of previous and ongoing efforts to develop such decision support systems shows that attempts to address the hydro-socio-economic effects on livelihoods have been deficient and fragmented. To date, no universal standard integration method or framework is in use. Existing integrated models application failures have pointed to the lack of stakeholder participation. In an endeavour to close this gap, this thesis focuses on an integrated model development with prediction capability, ICHSEA, developed in Avenues script language in ArcView 3.3, to take advantage of the mapping capability of ArcView. This model couples existing hydrology (SWAT), agronomy (PARCHED-THIRST) and socio-economic (OLYMPE) models to link livelihoods of resource-constrained smallholder farmers to water resources availability at catchment level in the semi-arid Olifants subbasin, South Africa. These three models were calibrated and validated using observed data and local stakeholder participation, prior to coupling in the integrated model. All the models performed well in representing the study conditions, as indicated by the statistical performance. The integrated model is generally applicable to any catchment. The study methodology was inspired by the need to enhance rural livelihoods and to close the gap of stakeholder involvement in building and applying integrated models to ensure acceptability and application in decision-making. Over 20 years, the predicted impacts of untied ridges and planting basins versus conventional rainfed tillage on surface runoff reduction were 14.3 % and 19.8 %, respectively, and about 41─46 % sediment yield reduction in the catchment. At 90 % confidence interval, family savings improved from US$ 4─US$ 270 under conventional rainfed to US$ 233─US$ 1 140 under supplemental irrigation. These results underscore the economic and environmental benefits that could be achieved by adopting the new crop management practices. A relationship between maize crop evapotranspiration and family savings under different crop management strategies was also derived for five farm typologies in the catchment.Item Food insecurity in Southern Africa :causes and emerging response options from evidence at regional, provincial and local scales(2007-02-19T13:26:47Z) Misselhorn, Alison AnneThe overarching objective of this thesis is to determine causes of food insecurity in southern Africa, and how it can best be addressed. This objective is addressed through a number of research questions and methods at three geographic scales: the regional, through a technique of meta-analysis which is used to synthesise 49 local-level household economy case studies; the provincial, through a Delphi panel of practitioner experience; and the local, using multiple research techniques, including participatory methods. An extremely diverse range of factors contributing to food-insecurity are found at all three scales, indicating that community- and household-specific dynamics give rise to forms of food insecurity. Two common processes, however, are argued to be common across all the casestudy communities in the regional-scale research. These are the closely related processes of cycles of intensifying vulnerability associated with livelihood ‘trade-offs’, and of communitylevel social capital changing into forms that undermine resilience to food insecurity - such as the decline in two-parent families. A further probing of social capital at the local level suggests that while social capital takes multiple forms, and further remains in many respects a problematic concept, it nevertheless provides a valuable lens through which powerful social dynamics might be examined in developing responses to food insecurity. Policy makers and change agents should carefully consider their role in building community social-capital that might enhance the ability of vulnerable communities to overcome livelihood constraints and adapt to the tremendous challenges posed by changing economic environments in southern Africa. Drawing on the research at all scales, a framework is provided that calls for a reconceptualisation of food-security interventions to focus on intervention processes, applicable at all scales and in all contexts across the region. The development of social capital, participation, co-ordination and learning interactions are explored as central elements in these processes. The framework asks for closer attention to both the appropriate mechanisms (such as policy) necessary to effect change, and the human dimensions that give these mechanisms agency. The findings of the thesis represent an additional shift in understanding food security to acknowledge that the value of a political economic interpretation of food security is limited independent of an understanding of the cross-scale social networks and relational interactions that ultimately configure and reconfigure it.