Photorealistic visualisation of urban greening in a low-cost high-density housing settlement, Durban, South Africa

摘要

Apartheid housing policies of the pre-1994 South African government, and the low-cost high-density housing programmes of the post-1994 government, have given rise to numerous urban environmental problems, some of which could be addressed in a cost-effective and sustainable manner through urban greening, while simultaneously promoting biodiversity. Public participation in the planning of urban greening has been identified as being of vital importance, without which urban greening projects run a high,and expensive, risk of failure. Previous studies indicate that the greening priorities of residents in low-cost high-density housing settlements may differ considerably from those of managers and experts tasked with the protection and extension of the natural environment resource base. A system of participatory decision support is therefore required to reconcile the greening requirements of the community, and the ecological benefits of biodiversity. If language, literacy, map literacy and numeracy difficulties are to be avoided, and a sense of place or belonging is to be invoked, such a participatory decision support system should, ideally, be visually based and capable of generating realistic eye-level depictions of the urban landscape. New computer-based landscape visualisation applications, which can directly utilise geographical information systems (GIS), computer-aided design (CAD) and Digital Elevation Model (DEM) data to produce detailed photo-realistic viewsheds, were deemed better suited to the task of visualising urban greening than existing GIS-based mapping systems, CAD and traditional landscape visualisation methods. This paper examines the process of constructing a 3D computer model of the Mount Royal low-cost high-density housing settlement, situated in the eThekwini Municipality, KwaZulu-Natal, South Africa. Visualisations including terrain, natural features, indigenous vegetation, houses and roads were produced and submitted, with a questionnaire, to experts from different disciplines, Mount Royal residents and neighbours. Results from the expert survey indicate moderate support for visualisation in professional decision-making. Both experts and residents expressed strong support for the accuracy and credibility of the visualisations, as well as for their potential in a participatory decision support system.