Using a hybrid methodology of dasyametric mapping and data interpolation techniques to undertake population data (dis)aggregation in South Africa

The ability of GIS to produce accurate analysis results is dependent on the accuracy and the resolution of the data. In many instances the resolution of census enumerator tract data is too coarse and therefore inefficient in conducting fine grained spatial analysis. Dasymetric techniques can increase the spatial resolution of data by incorporating related high resolution ancillary data layers allowing the primary data to be represented at finer resolutions. Areal interpolation relates to a geostatistical process of transferring data from one set of polygons to another. This paper proposes the application of a hybrid technique using dasymetric mapping and areal interpolation principals to overcome the issues of transferring data from arbitrary spatial units to fit for purpose analysis zones on demand. As a consequence the technique also overcomes the problems of coarse scale population data as well as issues relating to the modifiable areal unit problem (MAUP). The data used to illustrate the value and accuracy of the developed methodology is that of the 2011 census population data and ESKOM’s SPOT building count. The final outcome is an algorithm allowing the disaggregation and aggregation of population data to any spatial unit with a high level of accuracy.Keywords: Dasymetric Mapping; MAUP; Population; Census; GI

Planning for emergency services using GIS-based geographic accessibility analysis

Municipalities and metropolitan structures are required by law to provide sufficient response to emergency situations. In order to respond efficiently to disasters such as fire and flooding, it is necessary to place facilities optimally. This case study presents and applies a methodology to determine the locations of additional fire stations, using accessibility analysis rather than incident data which is often incomplete or unavailable. The required response time is based on the SANS 10090:2003 standard for various risks. The case study recommends that in the longer term seven additional fire stations are needed in conjunction with the existing 19 fire stations in the eThekwini Metro in South Africa to offer a response to fire incidents as required by the standard.&nbsp

Spatial trends in tourism within South Africa : the expected and the surprising

Abstract: Several researchers have highlighted the spatial imbalances of the tourism sector in South Africa. It has been noted that this sector is highly concentrated spatially in terms of its distribution and in relation to its potential local impacts across the country. Although it is broadly understood that the tourism sector is geographically uneven, the lack of sector comparative data at municipal level may inhibit the wide spread use of geographically comparative analyses of the contribution of the various dimensions of tourism in the South African space economy. The aim of this paper is to provide an indication of the value of such comparative analyses of the spatial trends and impacts of the tourism sector in local economies in South Africa. The discussion of the tourism space economy is based on an analysis of a local tourism database which contains details of the tourism performance of all local authorities in the country focussing on the period from 2001 to 2011. Whilst the study confirms the important role of metropolitan areas, secondary and coastal cities and typical tourism destinations in the tourism space economy, it also highlights the significance of some local places/economies that are not traditionally associated with tourism, as well as illustrating the significance of tourism spend in the local economies of a range of municipalities that might not be part of the ‘top’ tourist destinations in South Africa

Neighbourhood risk factors of recurrent tuberculosis in Cape Town: a cohort study using geocoded notification data

Background Individuals with a history of tuberculosis (TB) disease are at higher risk of developing a subsequent episode than those without. Considering the role of social and environmental factors in tuberculosis, we assessed neighbourhood-level risk factors associated with recurrent tuberculosis in Cape Town, South Africa. Methods This cohort consisted of patients who completed treatment for their first drug-sensitive TB episode between 2003 and 2015. Addresses were geocoded at neighbourhood level. Data on neighbourhood-level factors were obtained from the Census 2011 (household size, population density) and the City of Cape Town (Socio-Economic Index). Neighbourhood-level TB burden was calculated annually by dividing the number of notified TB episodes by the population in that neighbourhood. Multilevel survival analysis was performed with the outcome recurrent TB, defined as a second episode of TB, and controlling for individual-level risk factors (age, gender and time since first episode in years). Follow-up ended at the second episode, or on 31 December 2015, whichever came first. Results The study included 173 421 patients from 700 neighbourhoods. Higher Socio-Economic Index was associated with a lower risk of recurrence compared with average Socio-Economic Index. An increased risk was found for higher household size and TB burden, with an increase of 20% for every additional person in mean household size and 10% for every additional TB episode/100 inhabitants. No association was found with population density. Conclusion Recurrent TB was associated with increased household size and TB burden at neighbourhood level. These findings could be used to target TB screening activities