Browsing by Author "Mudavanhu, Shepherd"
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- ItemA cost-benefit analysis of using Rooikrans as biomass feedstock for electricity generation : a case study of the De Hoop nature reserve, South Africa(AOSIS Publishing, 2016) Mudavanhu, Shepherd; Blignaut, James; Nkambule, Nonophile; Morokong, Tshepo; Vundla, ThulileInvasive alien plants (IAPs) like Rooikrans (Acacia Cyclops) have several undesirable effects on both the natural environment and the social, economic and cultural wellness of society in the De Hoop nature reserve of the Western Cape Province. A few of these negative effects are: the change in coastal sediment dynamics, the change in seed dispersal dynamics, and the fact that it is overtaking native plants. However, Rooikrans can also potentially be used as biomass feedstock for electricity generation. Following a system dynamics modelling approach, the feasibility of using woody biomass from Rooikrans was investigated. The RE-model used data obtained from the Department of Environmental Affairs’ (DEA) Natural Resource Management (NRM) division, consulted with experts and conducted literature reviews with respect to the subject matter. Three scenarios were tested and the RE-model results showed that all scenarios have a positive cumulative Net Present Values (NPVs), with the exception of the baseline case scenario. This study shows that the production of electricity using Rooikrans woody biomass is a viable and feasible option in comparison with electricity production by diesel generators.
- ItemThe impact of economic policies and instruments on conservation agriculture in South Africa(Stellenbosch : Stellenbosch University, 2015-12) Mudavanhu, Shepherd; Vink, N.; Stellenbosch University. Faculty of Agrisciences. Dept. of Agricultural Economics.ENGLISH ABSTRACT: In South Africa, sustainable land use and management is paramount as the country’s agricultural natural resources are diverse, complex and vulnerable to degradation. To realise sustainable agricultural production and development, an agro-ecosystem-specific approach entailing soil, water and nutrient conservation agricultural practices is imperative. Conservation Agriculture is one of the agricultural production method that can be employed to ameliorate and prevent the degradation of South Africa’s agricultural land. The major aim of this study was to investigate how the uptake and adoption of conservation agriculture is influenced by economic policies and instruments in South Africa. To achieve this, an interactive research approach was followed initially involving an extensive literature review before scientific and empirical analysis was conducted. Firstly it was noted in the study that currently there is not any specific policy for conservation agriculture that has been promulgated in South Africa, but however there are a number of policies (i.e. Climate change policy, Carbon Tax policy, Land Reform policy, Trade policy, Water policy, Food and nutritional security policy, NEMBA regulations, CRDP, CARA, Organic production policy, Policy on Agriculture in sustainable development and the Environmental policy) that have been drafted which have the potential to positively influence the uptake and adoption of conservation agriculture by farmers across all the farming typologies (i.e. small scale, emerging and commercial farmers). The afore-mentioned policies were described and analysed with the purpose of establishing how they affect conservation agriculture using analysis criteria adopted from the field of political sciences. Criteria of effectiveness, unintended effects, equity, cost, feasibility and acceptability were constantly employed. In this regard, all the policies were tested to see how they affect conservation agriculture and to check if there was any alignment and harmonisation within the policy environment. It was found in this study that an alignment of the aforementioned policies is imperative in order to make the policies politically and administratively feasible which will lead to the swift implementation and effectiveness of the policies in meeting their core objectives. On this basis, it was deduced that the aforementioned policy mix has the potential to advance the uptake and adoption of conservation agriculture to further contribute to an enhanced food security and a sustainable resource base in South Africa. The policy mix analysed in this study, is however under specific constraints. These were identified and subsequently recommendations were made to ameliorate these constraints, in order to make the policies align with each other and to maximise the contribution of the policies towards the advancement of conservation agriculture in South Africa.
- ItemThe opportunity cost of not utilising the woody invasive alien plant species in the Kouga, Krom and Baviaans catchments in South Africa(AOSIS Publishing, 2016) Vundla, Thulile; Blignaut, James; Nkambule, Nonophile; Morokong, Tshepo; Mudavanhu, ShepherdThis study estimates the opportunity costs of using woody invasive alien plants (IAPs) for value-added products by estimating the net economic return from the value-added industries in South Africa. By 2008, IAPs were estimated at the national level to cover an area of 1 813 million condensed hectares in South Africa. A market has formed around their use for value-added products (VAP) like charcoal, firewood and timber in the Kouga, Kromme and Baviaans River catchments in the Eastern Cape province of South Africa. The net economic return from these value-added industries was estimated for the purpose of several management scenarios, and was then used to estimate the opportunity costs if they were not used. A system dynamics model was used to value and analyse the Net Present Value of clearing in the study area and to estimate the opportunity cost of the non-use of VAP. The study showed that the inclusion of VAPs in the project would yield higher net present values for clearing. The findings from this study suggest that a cofinance option of the total economic returns from VAP for clearing costs is the best management scenario for reducing the costs of clearing and maximising the net economic returns from clearing. The net economic returns of VAPs by 2030 are estimated at R23 million without the co-finance option and R26 million with the option. The cumulative net income from VAPs with co-financing over the period of valuation is estimated to be R609 million.
- ItemSustainable land use planning in the aftermath of the clearing of alien invasive plant species : a system dynamics modelling approach(Stellenbosch : Stellenbosch University, 2018-12) Mudavanhu, Shepherd; Vink, Nick; Blignaut, James Nelson; Stellenbosch University. Faculty of Economic and Management Sciences. Dept. of Agricultural Economics.ENGLISH SUMMARY : Biological invasions caused by invasive alien plant species (IAPs) pose diverse direct and indirect impacts on economic, social and environmental systems globally. The net impacts can be beneficial or harmful, although in most cases the negative impacts outweigh the beneficial effects. IAPs pose a significant threat to various systems through for example loss of biodiversity, excessive consumption of water, reduction in stream flow, health hazards to both animals and humans, increased fire risks and encroachment into agricultural lands and native ecosystems. Despite these negative impacts, IAPs to a limited extent also offer benefits to society, amongst them carbon sequestration, raw materials for manufacturing of value added products as well as habitat services for fauna. Given the predominant negative effects, however, the government of South Africa, through the Working for Water Programme (WfW), funded the clearing of IAPs mainly through labour intensive manual, mechanical and chemical means, as well as biological control using pathogens and insects as the control agents. Despite the aforementioned clearing efforts, IAPs have continued to spread exponentially, warranting more funding to finance the clearing operations targeting both new invasions and follow up clearing. In addition, the failure to contain invasions by IAPs has also led to sub-optimisation of agricultural land, which is attributed to a deficiency of land use planning frameworks and the ineffectiveness of laws governing agricultural land use in South Africa. As disclosed in this study, most of the research conducted to date has focussed mainly on control, distribution mapping, impact assessments and evaluation and to a lesser extent, partial cost benefit analyses of controlling IAPs. Given the complexities involved in the science of IAPs and land use planning decisions, the linear approach used in most studies has not been successful in fully capturing all the system elements, dynamics, causal and effect relationships thereof in order to understand the impacts of IAPs on the whole system. These complexities are further exacerbated by differences in land tenure systems. In order to understand the implications of the various land use options on land restored through clearing IAPs, within different contexts and tenure systems, it is imperative to undertake a non-linear analysis that captures the aforementioned complexities. This study identified the key decision-rules that should guide decision making in selecting the best land use and management options under diverse contexts, within the aforementioned complex and dynamic system. This was done using a system dynamics modelling approach and a multiple criteria decision analysis. The, focus was put on four study sites in the Western Cape and Northern Cape provinces of South Africa. Three system dynamics models and one multiple criteria decision analysis (MCDA) model were developed for: (i) understanding the integrated (i.e. both private and externality) benefits and costs associated with restoration of natural capital1 through the clearing of IAPs; (ii) exploring and identifying the land use capability of the land restored through clearing of IAPs and the alternative best use land types based on multiple criteria decision analysis; (iii) investigating the potential economic, social and environmental sustainability of the returns emanating from the land use types and value added industries implemented inter alia the valuation of ecosystem goods and services; (iv) assessing the economic feasibility of prospective land use types and value added products (VAPs) that can be pursued in the areas were clearing of IAPs has taken place in South Africa (with a specific focus on four sites in SA) (v) determining the opportunity cost of unrestored land cleared from invasive alien plant species in South Africa (vi) formulating scenarios under which the land use types, VAPs and management options considered will be tested using the system dynamics modelling approach in order to see the respective impacts thereof; and for (vii)understanding the policy shortcomings, options, and implications with respect to restoration of natural capital and land use types in South Africa. Validation tests of system dynamics models were also done. These included structure verification, parameter verification, dimensional consistency and extreme conditions tests which were undertaken to check for the structural validity. In addition, a behavioural validity test was conducted using multivariate sensitivity analysis to test the sensitivity of the Net Present value to the discount rate. As for the MCDA model, a parametric sensitivity analysis was conducted to test the sensitivity of the results to a change in the model parameters in order to build confidence in the analysis.Lastly, while efforts were made to capture all the economic, social and environmental aspects of IAPs management and land use planning decisions, not all core aspects were considered due to unavailability of data, methodological limitations and other unanticipated modelling complications. The limitations of the study were made explicit while concluding remarks and recommendations were made.