TITLE:
Seasonal ARIMA Modeling and Forecasting of Rainfall in Warri Town, Nigeria
AUTHORS:
Daniel Eni, Fola J. Adeyeye
KEYWORDS:
ACF, PACF, ARIMA, Rainfall, AIC, SBC
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.3 No.6,
August
25,
2015
ABSTRACT: We obtained historical data of
rainfall in Warri Town for the period 2003-2012 for the purpose of model
identification and those of 2013 for forecast validation of the identified
model. Model identification was by visual inspection of both the sample ACF and
sample PACF to postulate many possible models and then use the model selection
criterion of Residual Sum of Square (RSS), Akaike’s Information Criterion (AIC)
complemented by the Schwartz’s Bayesian Criterion (SBC), to choose the best
model. The chosen model was the Seasonal ARIMA (1, 1, 1) (0, 1, 1) process
which met the criterion of model parsimony with RSS value of 81.098,773, AIC
value of 281.312,35 and SBC value of 289.330,84. Model adequacy checks showed
that the model was appropriate. We used the model to forecast rainfall for 2013
and the result compared very well with the observed empirical data for 2013.