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Faculty of Engineering and Built Environment

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Subject: search.filters.subject.City planning--South Africa

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    Geographic information system as a vessel for conventional and alternative forms of zoning
    (2020-10-06) Kitching, Joseph; Musvoto, Godfrey Gombana
    Given the well-documented rates of global urbanisation and the fact that sub-Saharan Africa is set to urbanise at the highest rate during the next few decades, it is easy to understand that urban management systems will increasingly be under pressure to operate efficiently, effectively and transparently in order to circumvent potential economic, social and environmental disasters. A land-use management system is one of the management systems in urban areas aimed at ensuring health and safety, environmental quality, sustainability, social equity, and amenity, amongst others. Since the beginning of the twentieth-century, a key tool of planners wishing to accomplish this, has been zoning. Although zoning has been abused, and heavily criticised for that, the objectives of zoning systems around the world echo noble values such as promoting environments that are safe from flooding and fire hazards, that encourage harmonious communities and economic growth, that preserve agricultural land, and protect the natural environment. Conventional zoning, which was significantly shaped by the US Supreme court’s village of Euclid decision, focuses on the separation of incongruent land uses. There are also several other types of zoning such a flexible Euclidean zoning, performance- based zoning and even no zoning. Amongst the novel types are form-based codes, which stem from the New Urbanism paradigm. Form-based codes focus more on the public realm and the appearance of spaces and structures rather than the use of space. Practically and problematically, both conventional and alternative zoning schemes are currently comprised of a map and a separate text document. The map depicts the geographic dispersion of zones, typically related to properties or zoning districts. The text document contains regulations pertaining to the various zones, procedures and definitions. Alongside the inefficient separation of regulation and map, are the variations within single zones where specific, locally important, regulations apply to some properties within the zone. Geographic information systems (GIS) have been evolving since the mid-twentieth century and have gained serious traction with the advent of the microcomputer. Defined by many as a system that captures, collects, manages, analyses and presents geographic data and attributes, it is essentially a database linked to a geographic component, In the case of zoning, it currently comprises geographic properties linked to attributes describing the zoning. The rigid, surveyed, property boundaries make the vector or discrete objects model ideal for the representation of zoning. The raster model – the other half of the debate – is useful in representing images supporting the regulations. Given the need for more efficient systems, the pervasiveness of corruption and poor capacity in municipal systems, the omni-present abuse of power, the need for an informed citizenry and laws that are comprehensible, this study aims to see if GIS can be used to represent the regulations in conventional and alternative schemes. To establish this, six sample cities from around the world, more than twenty conventional zones in the eThekwini municipality and two zones from the Daufuskie form-based code were assessed to determine what types of regulations are common and whether they could be represented as either geographic norms or attributes to geographic features. This study found that GIS is able to represent all regulations in conventional schemes and most of the regulations in alternative zoning. It also found that some regulations are naturally inclined to spatial representation, others as attributes, and still others as scanned attachments or hyperlinks. This implies that there is no need for the separation of regulations from property and the confusion and potential misinterpretation that are associated with current practices.
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    Systems analysis of the transformation of South African cities
    (2017) Simelane, Thokozani Silas; Duffy, Kevin Jan; Pearce, Brian
    The need to quantify and model transformations that have taken place in the cities of South Africa is one of the grand challenges linked to country’s transition to Democracy. Given the complexities associated with different stages of city transformation, it is imperative that models used to unpack processes of city transformation are novel. In this study it emerged that statistical methods alone are not adequate to fully present, in a comprehensible way, all facets of drivers of city transformation. As a result, statistical methods have been combined with mathematical and system dynamics models. Results revealed that city transformations derive from a number of triggers. Underlining these are income, migration and houses. The empirical data collected through questionnaire survey that was later incorporated into mathematical models demonstrated that income is a primary driver that fuels city migration. System Dynamic Models demonstrated that the availability of houses or accommodation serve as constraints that keep the city population within the limits of the carrying capacity of a city. In addition it was further confirmed, through mathematical models that income has varying effects on the attractiveness of cities. This was found to be linked to the shape of the distribution of income in the city. A normally distributed income with a peak in the middle results in a city being more attractive than an evenly distributed income that peaks either at very low or high income levels. This observation brought forth a need to test heterogeneity when analyzing city transformation using income as an index. Mathematical Models that incorporated heterogeneity demonstrated the usefulness of systems analysis in unpacking the mechanism of city transformation, a component of city management that requires serious consideration for planning, budgeting and provision of limited resources like houses in the cities. Success of methods used in this study led to a conclusion that these can be enhanced through other techniques like agent based models. With this call, improvements on this study that can be attained through these techniques are recommended. This will enrich the understanding of the transformation and dynamics of cities under different conditions than those that exist in South Africa.