SPI Criterion For Drought Modeling And Forecast
Fourier spectral analysis is used to examine the cyclic structure for drought patterns and develop a long-term
periodic model for precipitation data obtained from the arid region of Kuwait. The Standardized Precipitation Index (SPI)
criterion is used to perform a time scale of 24 months. The periodogram technique reveals periodicities of 14, 19, 26, 31, 43,
64, 103 and 258 months. It is advocated here that the 26- and 258-month periods present in the data are attributed,
respectively, to a Quasi-Biennial Oscillation pattern and a solar cycle over which the magnetic polarity of the sun first
reverses then reverts to its former state. The detected periods are manipulated in the SPI model to produce drought forecasts,
which suggest that until the end of year 2024 the climate is considered normal to very wet.
Keywords- SPI; Periodicity; Drought risk assessment; Arid region; Sunspots.