Identifying the challenges of creating an optimal dissemination geography for census

Abstract

The importance of census data in government and private-sector planning cannot be underestimated. However, the geographic level at which it is made available for different users, is a highly debateable issue. It is crucial that census data is disseminated in such a way that it satisfies most user needs as far as possible, to ensure that there is optimum use of the information and that maximum value for money is provided. In the past, Statistics South Africa disseminated data at the same geographic level created for data collection. This causes problems for data users and calls for the creation of a separate output geography rather than using the original collection geography.
The research was done on two levels: first, an overview of output geographies, as well as examples of developed and successfully used tools to generate these areas within a geographical information system. Some of these could be used in the South African milieu. Secondly the paper discuss aspects such as the population size variation of EAs, in order to inform the criteria for the creation of the ideal small area (SA) layer to satisfy the majority of user needs. Lastly the paper describes briefly the challenges faced to create the 2011 output geography. The results indicate a strong resemblance between the two EA population size patterns of 2001 and 2011, influenced by the EA demarcation rules. The challenges identified in the process of creating the SAL as a census output geography need to be taken into consideration to enable a more useful and user-friendly output.