A Probit Regression model approach for Predicting Drought Probabilities in Zimbabwe using the Southern Oscillation Index

Abstract

This paper focuses on the methodology of determining probabilities of meteorological droughts in Zimbabwe. The Probit regression method is used. Mean annual rainfall for the years 1974 to 2009 is used in this study. The results show that a very low value of the Southern Oscillation Index (SOI) for September precedes the occurrence of a meteorological drought in Zimbabwe by at least a year. Mean annual rainfall drought threshold value of 570 mm is used to categorize drought years from 1974 to 2009. Results show that a negative Southern Oscillation Index value for September predicts at least 67% chance of drought in the coming year.

DOI: 10.5901/mjss.2014.v5n20p656