Forecasting Monthly Rainfall of Karyes, Chios Island, Greece, Central-Eastern Mediterranean Basin Using the ARIMA Method ^†

Chios Island undergoes scarcity of freshwater, forcing local authorities to establish a sea-water desalination plant to cope with island’s water needs. Karyes village is plentiful with freshwater springs, augmented every year by the rainfall occurring over this particular district, supplying, in turn, some high-quality freshwater obtaining spots into the capital of Chios, thus establishing an important freshwater origin of the entire Chios Island itself. The present study administers the Box–Jenkins method, utilizing SARIMA (Seasonal Autorregressive Integrated Moving Average) model to achieve short term predictions of monthly rainfall in Karyes village, modeling past rainfall time series and forecasting future ones. The model which best fits to both interpretations of the past rainfall data is selected, assessed by several statistical model evaluation criteria.