Rainfall Drought Simulating Using Stochastic SARIMA Models for Gadaref Region, Sudan

Sudan is one of the countries which economy depends on rain fed agriculture and also facing recurring cycles of natural drought. For many decades, recurrent drought, with intermittent severe droughts, had become normal phenomenon in Sudan. This paper presents linear stochastic models known as multiplicative seasonal autoregressive integrated moving average model (SARIMA) used to simulate monthly rainfall in Gadaref station, Sudan. For the analysis, monthly rainfall data for the years 1971–2010 were used. The seasonality observed in ACF and PACF plots of monthly rainfall data was removed using first order seasonal differencing prior to the development of the SARIMA model. Interestingly, the SARIMA (0,0,5)x(1,0,1)12 model developed here was found to be most suitable for simulating monthly rainfall over the Gadaref station. This model is considered appropriate to forecast the monthly rainfall to assist decision makers establish priorities for water demand, storage and distribution.