Investigation of Rainfall Variability over Kenya (1950-2012)

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Date
2018
Authors
Sagero, Philip O.
Shisanya, C.A.
Makokha, George L.
Journal Title
Journal ISSN
Volume Title
Publisher
JEAS
Abstract
This study investigates the rainfall variability from 33 stations, for a period of 63 years (1950 – 2012) over Kenya. Coefficient of Variability and non-parametric Mann- Kendall test at 5% level of significance was used to assess the variability and trend, respectively. The Sen’s slope estimator was then used to find the magnitude of the changeover the time period. It was observed that October to December season had a high inter-annual variability, with most stations having greater than 50% of the Coefficient of Variation compared to March to May season, which had only 4 stations with over 50% Coefficient of Variation. Insignificant decreasing trend was noted during the March – May rains, while insignificant increasing trend in October – December rains. On a spatial scale, a negative trend was noted in the northern part of the country and the opposite condition was noted in western regions of the country, around Lake Victoria area. The results indicate a likelihood of negative impact on sectors of the economy that relay on rainfall, because of negative trend in March – May long rains, which accounts for most of rains received annually in Kenya. Although the October – December rains have an increasing trend, they are unreliable due to high inter-annual variability.
Description
Research Article
Keywords
Rainfall, Climate change, Trend analysis, Mann-Kendall, Coefficient of Variation
Citation
Sagero, P.O., C.A. Shisanya and G.L. Makokha. 2018. Investigation of rainfall variability over Kenya (1950-2012). Journal of Environmental and Agricultural Sciences. 14: 01-15.