Kriging the rainfall in Lesotho

Abstract

In this paper, three geostatistical kriging techniques are considered for estimating the monthly rainfalls at points or over areas such as catchment basins, in the highland regions of Lesotho. The data available for making these estimates come from the monthly pluviometric recordings made at about 100 raingauges in Lesotho and adjoining parts of South Africa, from 1922 onward. Two problems were encountered: missing monthly values at some raingauges and the sparsity of raingauges in highland areas where estimates are required. Of the three methods tested, one based on using the average summer or winter rainfall as an external drift gave the best results. -Authors