Assessment of recent drought severity for natural grassland at three locations

Abstract

The relative severity of drought in natural grassland during three growing seasons was analyzed for three South African weather stations. Computer simulation of grassland water use, based upon weather records, was used to quantify drought and to compare the conditions which prevailed during 1981/82, 1982/83 and 1983/84 to expected conditions at Glen, Bethlehem and Potchefstroom. Probabilities for expected conditions were estimated from frequency distribution analysis of simulations from historical weather records. All three sites suffered at least one year of extreme drought, in which grassland water use was lower than that expected during the driest year in ten.