The impact of climate variability on pastoralism: forage dynamics and trends in Cattle population in kajiado county, kenya

Abstract

The study was conducted to determine the influence of climate variability on pastoralism in Kajiado County of Kenya. Since pastoralism encompasses several components, the research limited its focus only to two aspects namely; forage and cattle production - further narrowed to cattle population. Rainfall data from Ngong Divisional Office, Mashuru and Magadi Soda Works Meteorological Stations were factored in as climate variability parameter. Specifically, the project aimed to; determine the existence and level of climate variability in Kajiado County, identify forage change and examine the change dynamics relative to rainfall characteristics, and determine the relationship between climate variability and cattle population in the study area. Input data were organized in excel and analyzed using Statistical Package for Social Scientists (SPSS). Standard deviation, mean, range and coefficient of variation (C.V.) were calculated for rainfall data for the three Meteorological stations over the period 1964 - 2011. Data on annual cattle population gathered from Kajiado District Veterinary Office for the period 1979 - 2009 was regressed and correlated against annual rainfall totals over the same period. Data on forage levels for the period 1982 - 2004 was processed in the form of Normalized Differential Vegetation Index (NDVI) for sampled areas within the four ecozones. Time series of these data were then averaged into dekadal means and annual averages then regressed and correlated with corresponding rainfall data at lags 0 and 30days. Findings for this research suggested that rainfall over Kajiado had overtime revealed high variability both spatially, seasonally and inter-annually. Spatial variations revealed that Mashuru to the East had exhibited higher variability (C.V. = 26%) compared to areas around Ngong in the North (C.V. = 24%) and areas around Lake Magadi in the West (C.V=21%). Similarly, there was higher variability during the short-rain seasons as compared to long-rain seasons over the three stations. The results indicated that forage indices were strongly related to rainfall amounts at Magadi Soda Works Meteorological Station, accounting for 74% of forage at onset and 92% at peak vegetation performance, iii while at Mashuru Meteorological Station it accounted for 48% at onset and 89% at its peak. Annual Cattle population was found not to have significant association with annual rainfall amounts at the three stations thus annual rainfall totals alone was concluded not to be a good predictor of annual cattle performance. The study was limited by unavailability of daily rainfall data for the three stations. It was also limited by unavailability of cattle population statistics - available only on annual census. The project thus recommended more frequent periodical livestock census, more weather monitoring infrastructure be installed, formulation of policy based pastoral education