This documentation describes the fourth version of a database of administrative units with associated population figures for Africa. The first version was compiled for UNEP's Global Desertification Atlas (UNEP 1992, Deichmann and Eklundh 1991), while the second version represented an update and expansion of this first product (Deichmann 1994, WRI 1995), and the third was another update and expansion (Deichmann 1997).
This new version for Africa provides considerably more detail: more than 109,000 administrative units (83,000 of which are in South Africa), compared to about 800 in the first, 2,200 in the second version and 4,700 in the third. In addition, for each of these units a population estimate was compiled for 1960, 70, 80, 90 and 2000 which provides an indication of past population dynamics in Africa.
As before, the database is largely a compilation of existing data sources. The institutions listed in the acknowledgments generously made digital boundary data sets available which have been integrated into the continental database. The main contribution of the project described here has been to compile all these data from different sources, put them into a consistent format, and to produce matching population figures.
This fourth version of the database was again compiled from a large number of sources (which are listed in Appendix A4). Clearly the incremental improvements made in each version highlight the fact that the compilation of a digital database of this kind needs to be seen as a process of continuous improvement rather than as a one-shot effort.
The main difference between this verison and previous efforts is that it includes a mechanism that incorporates new census and administrative data as they become available, and which ensures consistency with other sources and provides easy access to the data.
The following part of this documentation describes the development of data layers of administrative boundaries with population totals. The format of this documentation generally follows that used in the Asia database documentation (Deichmann 1996a). The following section gives general background information on data sources and estimation procedures. It also discusses data quality issues and limitations of the database which should be kept in mind in any application. Part II presents the methodology used for constructing a set of gridded data layers of population distribution. Since the same methodology was used in the construction of population distribution grids for Asia, this part of the documentation is largely identical with that for Asia. Finally, the Appendices contain a table of summary information, the format of the attribute tables, detailed data sources and processing steps for each country.
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