|In a previous post, we referred to the importance of the 400mm rainfall line (isohyet ) as a fundamental dividing line in our economy and human settlement patterns. We have included the rainfall map to compare it with a map of the distribution of population majorities in South Africa.
As an example of the impact of this line, the following map shows how the population majority align with rainfall. East of the 400mm isohyet, the black population, generally dominates while, to the west of the line, the coloured population. This line impacted the Tomlinson Report released in 1954 by the Commission for the Socioeconomic Development of the Bantu Areas, known as the Tomlinson Commission. The South African government commissioned that to study the economic viability of the native reserves (later formed into the bantustans).