The use of 3D geovisualisations for urban design : the case of informal settlement upgrading in South Africa

Abstract

Informal settlements are a common occurrence in South African due to housing backlogs and shortage of housing subsidies, and are often located on disputed land. To improve in-situ circumstances of these communities, informal settlement upgrades and urban design is required. Spatial data and maps are essential throughout the entire upgrading and urban design process in order to understand the current environment, plan new developments and communicate planned developments. All stakeholders need to understand maps to ensure active participation in the urban design process. Previous research demonstrated that a large number of planning professionals in South Africa have a relatively low level of map literacy, which is considered to be inadequate for effective planning. Many researchers proclaimed that because 3D visualisations resemble the real environment more than traditional maps, and are more intuitive, therefore 3D geovisualisations are easier to interpret. The goal of this research is to investigate the use of 3D geovisualisations (specifically 3D city models) for urban design in informal settlement upgrading in South Africa. To achieve this goal, the following topics were investigated: modelling processes (manual and procedural); visual design (visual characteristics, visual complexity and visual variables); and cognition related to spatial tasks on 3D geovisualisations and comparable alternatives (i.e. topographic maps, aerial photographs, 2D maps) when performing basic map reading tasks. Procedural modelling was found to be a feasible alternative to time-consuming manual modelling and has the capabilities to produce high-quality models. When investigating the visual design, the visualisation characteristics of 3D models of informal settlements, and relevance of a subset of visual variables for urban design activities of informal settlement upgrades were assessed. The results were used to produce various maps and 3D geovisualisations that were presented in quantitative user studies and expert interviews. The results of four user studies and expert interviews contributed to understanding the impact of various levels of complexity in 3D city models and map literacy of future geoinformatics and planning professionals when using aerial photographs, 2D maps and 3D models. The research results could assist planners in designing suitable 3D models for use throughout the entire urban design process.

As gevolg van agterstande met behuising en ’n tekort aan behuisingsubsidies, is informele woongebiede ’n algemene verskynsel in Suid-Afrika en is dit dikwels op betwiste grond geleë. Om hierdie in-situ omstandighede van die gemeenskappe te verbeter, is daar opgradering en stedelike beplanning nodig. Ruimtelike data en kaarte is deurlopend noodsaaklik vir die volledige opgradering en stadsbeplanningproses om sodoende die huidige omgewing te verstaan, nuwe ontwikkelings te beplan en die beplande ontwikkelings te kommunikeer. Dit is noodsaaklik dat alle rolspelers kaarte verstaan om aktiewe deelname aan die stedelike beplanningsproses te verseker. Vorige navorsing het getoon dat ’n groot aantal professionele beplanners in Suid-Afrika ’n relatiewe lae vlak van kaartgeletterdheid het, wat beskou word as onvoldoende om doeltreffende beplanning te kan doen. Baie navorsers maak daarop aanspraak dat 3D geovisualiserings nader aan die werklike omgewing is en dat dit meer intuïtief en makliker as tradisionele kaarte vertolk kan word. Die doel van hierdie navorsing is om die gebruik van 3D geovisualiserings (meer spesifiek 3D stadsmodelle) te ondersoek om die ontwikkeling van stadsbeplanning in informele woongebiede in Suid-Afrika op te gradeer. Om hierdie doelwit te bereik, is die volgende onderwerpe nagevors: modelleringsprosesse (volgens handleidings en prosesse); visuele ontwerp (visuele eienskappe, visuele kompleksiteit en visuele veranderlikes); en die herkenning van verwante ruimtelike take op 3D geovisualiserings en vergelykbare alternatiewe (byvoorbeeld topografiese kaarte, lugfoto’s, 2D kaarte) wanneer basiese kaartlees take uitgevoer word. Prosedurele modellering is ’n haalbare alternatief teenoor tydrowende modellering volgens handleidings en dit het die moontlikhede om hoë kwaliteit modelle te lewer. By die ondersoek van visuele ontwerp is die visuele karaktereienskappe van 3D modelle van informele woongebiede en die relevantheid van ’n onderafdeling van visuele veranderlikes beoordeel/geassesseer vir ontwerpaktiwiteite by informele nedersettings. Die resultate is gebruik om verskillende kaarte en 3D geovisualiserings te skep wat in kwantitatiewe gebruikerstudies en in onderhoude met kenners aangebied is. Die resultate van vier gebruikerstudies en onderhoude met kenners, het bygedra om die impak te verstaan van verskillende moeilikheidsvlakke van 3D stadsmodelle en kaartgeletterdheid van toekomstige geoinformatika- en professionele beplanners wanneer lugfoto’s, 2D kaarte en 3D modelle gebruik word. Die navorsingsresultate kan beplanners ondersteun om geskikte 3D modelle te ontwerp wat deurlopend in die stedelike beplanningsproses gebruik kan word.