4. Electronic Theses and Dissertations (ETDs) - Faculties submissions
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Item Quantifying and Mapping Urban Ecosystem Services in Johannesburg, South Africa(University of the Witwatersrand, Johannesburg, 2024) Friemond, JosephModern cities face a wide range of challenges such as flooding and heat stress, which are driven by urbanisation and exacerbated by the impacts of climatic change. The ecosystem services provided by green spaces in cities have become a crucial element in addressing these challenges by supporting climate change mitigation and adaptation. The first step in maintaining and improving the supply of these services is their quantification and mapping. However, large knowledge gaps exist in South Africa and Johannesburg relating to the provision of urban ecosystem services. This study aimed to quantify the supply of three important urban ecosystem services (carbon storage, runoff retention and cooling) and map their distribution across the wards of Johannesburg. Carbon storage was quantified through field sampling of four urban forest types (roadside trees, parks, gardens and nature reserves) and the use of biomass equations. InVEST's urban flood risk mitigation model was used to quantify runoff retention, while cooling was quantified by deriving land surface temperatures from Landsat satellite imagery, which were then used as inputs for a cooling indicator. All three services were mapped across the wards of Johannesburg and then normalised for comparison. The results revealed that Johannesburg's urban forest stores 2.4 million tonnes of carbon, with significant differences in carbon storage between forest types. Johannesburg’s ecosystem services provide great value in mitigating urban challenges, retaining 20.9 million m3 of runoff during a 50 mm storm, and providing cooling services across most of the city. However, the supply of these services is unequal, with large spatial disparities between the northern and southern regions in the city. Numerous wards receive critically low supply of these services, making them vulnerable to the impacts of climatic change. The northern- central wards have optimal supply of all three services, highlighting synergies between services. Ultimately, these three services have immense value in the Johannesburg context and play key roles in supporting the city’s climate change mitigation and adaptation, through the multi-functional delivery of ecosystem services from urban green infrastructure. By mapping these services at the ward scale, our findings can be used to accurately inform authorities and decision makers of priority areas for intervention, as well as key areas for conservationItem Environmental spatial planning: achieving sustainable development in sensitive areas(2019) Snyman, Louis Gerhardus; Humby, Tracy-LynnSouth Africa is at a crossroads. Near stagnant economic growth and rising levels of poverty are at the top of the political agenda. In response, the state has adopted a rapid developmental growth strategy in an attempt to build an efficient economy that makes inroads into reversing a legacy of social and economic marginalisation. In a rural context, this includes supporting large industrial developments which include extractives-related activities that exploit precious natural resources. The status quo has positioned many state-sanctioned development plans on a collision course with the sustainable utilisation of sensitive natural landscapes. It is thus vital to investigate how planners and decision-makers appropriately reconcile the seemingly conflicting environmental, social and economic considerations that constitute ‘sustainable development’. This fine balancing exercise requires tough compromises to create harmony between imperatives deeply embedded in the language of rights. The two intersectional areas of law at the centre of this debate are environmental management and spatial planning; each of which prescribe numerous tools that attempt to operationalise the balancing of the often conflicting imperatives within ecologically and culturally sensitive areas. The difficulty in managing development in sensitive areas is the application of interconnecting, yet often conflicting, legislative and governance systems. Therefore, the key research questions are: How are spatial planning and environmental management paradigms being applied in sensitive areas in South Africa? Moreover, what are the chief factors inhibiting or promoting the effective use of spatial planning and environmental management to achieve a reconciliation between development and conservation in sensitive areas? Lastly, what are the legal dimensions of these questions, if any? The purpose of this study is thus to suggest ways in which spatial planning and environmental management can be better integrated to achieve the desired outcome of sustainable development in sensitive areas. Although this is a pressing issue, little empirical research has been conducted in this specific area and previous work has failed to address the specific legal, institutional and operational obstacles that exist in creating a cohesive and inclusive system.