Discussion Paper No. 244 of 2020 on Assessment of Meteorological Drought in Main Climatic Zones of Kenya

Abstract

This paper presents a spatio-temporal assessment of meteorological drought in four counties of Kenya using Standardized Precipitation Index (SPI). Monthly rainfall data from the Climate Hazards group InfraRed Precipitation with Stations (CHIRPS) dataset from 1981 to 2015 was transformed into a Gamma Distribution Function to characterize drought at 1, 3, 6, 9 and 12 months temporal scale. During the entire period, dry zones recorded 29 extreme and severe seasonal drought conditions compared to 18 in very dry zones. Generally, seasonal SPI declined in very dry zones but increased in the dry zones although March-April-May (MAM) period experiences more extreme droughts. In dry zones, the number of extreme and severe droughts more than doubled from 7 to 16 between 1980 and 1990 and 2000-2010, while in very dry zones it reduced by more than half from 5 to 7. The findings of 3 months SPI compared favourably to observed drought over the country, buttressing the use of SPI to monitor drought conditions. Differences in drought patterns across main climatic zones challenges the one size fits all approaches used to drought management in Kenya. Replicating drought analysis at lower spatial scale and assessing associated sectoral impacts is essential in effective drought management.