Modelling the ecological-economic impacts of restoring natural capital, with a special focus on water and agriculture, at eight sites in South Africa

[摘要] ENGLISH ABSTRACT: The restoration of natural capital has ecological, hydrological and economic benefits. Are these benefits greater than the costs of restoration when compared across a range of dissimilar sites? This study examines the impact of restoration at eight case study sites distributed throughout South Africa. The benefits of restoration include improved grazing values and crop yields, improvements in water yield and quality, soil carbon improvements, wild products, lumber, fuelwood and electricity. The impact of restoration on all forms of natural capital (i.e. cultivated, replenishable, renewable and non-renewable) is therefore quantified. The costs of restoration include depreciation on capital expenditure, labour costs, equipment and bond refinancing costs.The literature review done during this study presents three frameworks. The first framework classifies social science using the classification scheme of Burrell and Morgan. It shows that system dynamics modelling and neoclassical economics share the same epistemological and ontological characteristics, both of these fall within the naturalistic paradigm, which also characterises most of scientific research. System dynamics modelling and neoclassical economics, however, digress in the Flood and Jackson classification scheme, which is the second framework for classifying social science. Neoclassical economics is characterised by a small number of elements and few interactions between the elements. Systems dynamics modelling, on the other hand, is characterised by a large number of elements and many interactions between the elements. The nature-freedom ground motive is subject to a number of criticisms, including the fact that it introduces dualistic thinking into the analysis, as well as that it does not adequately address normative or moral issues. The framework of Dooyeweerd, the third framework, is presented as a means of transcending the nature-freedom ground motive. Although the nature-freedom ground motive is largely utilised in this study, the analysis does transcend the traditional economic approach in a number of areas. These include, for example, a focus on transdisciplinary methods, disequilibria, adopting a case study approach, and empirical estimation instead of theoretical models.The restoration case studies in this study are examples of individual complex systems. Eight system dynamics models are developed to model interactions between the economic, ecological and hydrological components of each of the case studies. The eight system dynamics models are then used to inform a risk analysis process that culminates in a portfolio mapping exercise. This portfolio mapping exercise is then used to identify the characteristics and features of the different case study sites based on the risk profile of each sites. This study is the first known application of system dynamics, risk analysis and portfolio mapping to an environmental restoration project. This framework could potentially be used by policymakers confronted with budgetary constraints to select and prioritise between competing restoration projects.

[发布机构] Stellenbosch University