|
|
|
THE USE OF GIS IN INFORMAL SETTLEMENT UPGRADING: ITS ROLE AND IMPACT
ON THE COMMUNITY AND ON LOCAL GOVERNMENT
AProfessor John Abbott
Department of Civil Engineering,
University of Cape Town,
Private Bag, 7701, Rondebosch,
South Africa.
Tel. ++27 21 650 2605
Email: abbott@ebe.uct.ac.za.
At the least it is an essential component of development. This paper though would go much further,
and argue that it is central to development, to the extent that informal settlement upgrading cannot be
mainstreamed without it.
For the reality is that informal settlements are extremely complex environments. To date the vast
majority of upgrading initiatives have been sector-based. But these take place without any real
understanding of their impact on other sectors, or even their long-term impact. And there is evidence
that the impact can be marginal or even negative (Verma, 2000; Amis, 2001). The philosophy
underpinning this methodology is that only through the use of an effective spatial data management
system can different interventions can be related, their impact evaluated and, ultimately, their input
integrated. Such a system, though, will only carry legitimacy and credibility if the process is under the
overall control of the community. And that is the key issue of relevance to this conference.
The use of generic data
This methodology differs from others that use GIS, such as Belo Horizonte for example, in that it is
driven by the need to manage spatial data effectively, rather than manage a physical plan. This makes
the relationship between the community and the spatial dataset a key element of the upgrading
process. In constructing the spatial data management system around this relationship, the first point to
recognise is that there are two, distinct, core datasets. The first of these relates to the dwelling, and
essentially represents the physical and spatial data. The second relates to the people living in the
dwelling, and provides the social and economic data. Interestingly, the cadastre, or land boundary
system, is not considered to be an independent dataset, but rather to be simply one element of the
physical and spatial data.
Within these two data sets, there are different layers of data, some of which are primary and some
secondary, with the distinction being that, while primary data is obtained from a clearly defined
source, secondary data derives from a manipulation of different primary datasets.
Not all datasets need to be available to all parties. For example, communities may conduct specific
surveys to meet their own needs, and these would not have to be made available necessarily to other
parties. Thus it is useful to draw a distinction between primary data that is available to all parties and
primary data that is specific to one particular party’s needs. The former will be termed here as generic
data. It is this generic data that provides the foundation for all analysis and development in informal
settlement upgrading.
As mentioned previously, the basic structuring elements for the spatial data management system are
the dwelling and the people living in the dwelling, with the specific identifier for the latter group being
the head of household. In database terms, these two will be given a unique identifier, and all other data
will be linked to one or the other. These two database-structuring elements will then be linked, where
necessary, through the dwelling identifier. Within this contextual framework, the primary data can
then be grouped or structured in a number of different ways. The system described here is based upon
a detailed ‘data flow diagram’ which is shown in figure 1 below (Abbott, 2001).
|
|
|