Forecasting Drought in Puerto Rico with the Standard Precipitation Index

Abstract

The main premise of the current effort is that the use of a drought index, such as Standard Precipitation Index (SPI), may lead to a more appropriate understanding of drought duration, magnitude and spatial extent in Puerto Rico. The importance of the Index may be marked in its simplicity and its ability to identify the beginning and end of a drought event. Thus, it may point towards drought contingency planning and through it to drought alert mechanism. The present approach examines the SPI drought index application for important stations throughout Puerto Rico and it is evaluated accordingly by historical precipitation data. Different time series of data from 7 precipitation station, covering the period 1970-2014 and for time scales of 1,3,6,9 and 12 months, were used. The computation of the index was achieved by the appropriate usage of a pertinent software tool. The results underline the potential that the SPI usage exhibits in a drought alert and forecasting effort as part of a drought contingency planning posture. Key Terms - Drought Contingency Planning, Drought Index, Geo-Statistical Methods, Standard Precipitation Index.