Climate variability trends in the Semi-Arid Catchment of Karamoja and Teso sub-regions of Uganda Climate variability in the semi-arid Catchment, Uganda

Abstract

Frequent and severe droughts associated with climate change are making water scarcity more acute in arid and semi-arid areas of eastern Africa, thus affecting food and forage availability. The objective of this study was to assess spatial-temporal trends and variability in temperature and rainfall over the semi-arid region of Kapir Catchment in northeastern Uganda. Mean temperature and rainfall time series (1980-2009) of four data points, hereafter referred to as stations (Amuria, Kaabong, Kotido and Moroto Stations) were examined. Ordinary Least Squares (OLS) regression and Cumulative Sum (CUSUM) chart were used for detecting trends and sequential shifts in time series, while the standard temperature index (STI) and standard rainfall anomaly (SRA) were used to detect hot and dry years, respectively. There was an increase in both temperature and rainfall at the catchments scale, though only the temperature increase was significant (p < 0.05). Increase in rainfall was lowest in Amuria Station, which received the highest rainfall. On the other hand, total annual rainfall significantly increased in Kotido and Moroto Stations. October rains significantly increased in all areas, except Amuria, and resulted into a significant increase in the Catchment September, October and November (SON) season rainfall. January rainfall increased significantly only in Kaabong Station. Variability of both temperature and rainfall was higher in the first decade of analysis than in the third decade. Positive shifts in temperature trends occurred after 2000. Adaptation options in the catchment should consider the climate variability through, among others, crop science applications and ecosystem based adaption.