Precipitation Extremes and Their Pattern in the Central Highlands of Ethiopia: SPI Based Analysis

Abstract

Precipitation extremes are the most important occurrences that need to be studied with maximum possible care as they are always related with damages of any kind. Extreme precipitation deficit is the most notable among the occurrences of the extreme climate events in Ethiopia. However, the other extreme is also essential in understanding the precipitation and the effect of climate variability in Ethiopia. Accordingly, the present study critically focused on examining the occurrences of both extremes for detecting and monitoring extreme drought and wet conditions in the central highlands of Ethiopia. A standardized precipitation Index has been employed on a thirty years monthly precipitation record. The results indicated that the long term precipitation analysis based on SPI showed that there has been relatively some deficit precipitation amounts observed in the third decade of the study period. A total of 17 extreme dry conditions occurred in this particular decade and the same decade had comparable occurrences of 16 extreme wet ones in the district The other two decades had 3 and 9 extremely deficit precipitations conditions with their respective orders, decade first and second. Similarly in thirty years of monthly total precipitation record, the SPI detected that there were 10 and 3 extreme precipitation surplus in the first and second decades respectively.

Keywords: Extremes, SPI