Koppen Climatic Zonation

When hydrological landscapes, or climatic drivers of hydrological processes, are in a state of flux, baselines of climate and climatic zones are important, because these baselines are the references against which hydrological response comparisons may be made, for example, of possible changes in the climate regime. The hydrological responses to perturbations of climate include changes in total streamflows and their seasonal distributions. Baselines against which climate impacts may be assessed are all the more important in water resources management because hydrological responses, especially to changes in rainfall, are non-linear. In order determination of Köppen climate zones over South Africa, Lesotho and Swaziland, the 1` x 1` latitude/longitude raster (i.e.1.7 x 1.7 km) of median monthly precipitation from Lynch (2004) was used, while for monthly means of daily average temperatures the 1` x 1` gridded values, derived from Schulze and Maharaj (2004), were used. A computer program was written to identify the Koppen class at each of the 429 700 grid points covering southern Africa.