Spatial planning solutions to mitigate poor air quality in South African dense, low-income areas

Abstract

Poor air quality is considered as among the most significant environmental health risks globally. Spatial planning is intrinsically linked to poor air quality within urban areas, since land use changes dictate the location of significant poor air quality sources, influence the urban form and guide future development. The notion is further exacerbated by the segregated land use patterns left by the previous regime, resulting in incessant urban sprawl of dense, low-income where air quality is particularly poor. This research aimed to investigate whether spatial planning may well be implemented as a possible solution to mitigate poor air quality within South African dense, lowincome areas. In doing so, the research employed an exploratory sequential research design by collecting literature, analyse the results, create an assessment tool and subsequently employ it to a case study for testing. Literature was investigated to identify contributing drivers of poor air quality within South African urban areas. The research further explored contemporary spatial planning approaches and their implementation to limit poor air quality in urban areas. Through a process of coding, reconstructed data of the contributing drivers were progressed into an assessment matrix to identify the most significant sectors of poor air quality in SasolburgZamdela. Subsequently, a similar process was used to progress the contemporary spatial planning approaches into "urban development principles" that were employed in the compilation of three distinct development models (realistic, extreme and spatial inclusion) for SasolburgZamdela. In exploring the feasibility of contemporary spatial planning approaches to address poor air quality, AERMOD was used to calculate the emission concentrations of each development model. The analysis demonstrated that the implementation of the "urban development principles" reduced PM2.5 concentrations in all three development models. In relation to the baseline model, the overall predicted 99th percentile emission concentrations were reduced in the realistic development model by 13.7%, in the extreme development model by 89.6% and in the spatial inclusion development model by 49.9%. These development models incorporated more compact development by locating high density, mixed-land use development in proximity to transit orientated developments and high order transportation corridors, resulting in agglomeration of land uses that curb incessant urban sprawl. The research revealed that the identified "urban development principles" may well be implemented as spatial planning solutions to mitigate poor air quality within South African dense, low-income areas. It highlighted that in facilitating the mitigation of poor air quality, a collective impact approach should be followed by implementing various spatial planning solutions, inter alia; compact urban development that promotes densification, mixed land use development that is adequately integrated with transit-orientated development and effective green infrastructure; especially surrounding high pollution areas.