Evaluation of Historical Dry and Wet Periods over Lake Kyoga Basin in Uganda

Abstract

Rainfall datasets from the Uganda National Meteorological Authority (UNMA) for 1981–2017 and two reanalysis datasets (Climate Hazards Group Infrared Precipitation with Stations data (CHIRPS) and Tropical Applications of Meteorology using Satellite data (TAMSAT) were used to compute drought and flood tendencies from 1981 to 2017. The cumulative departure index (CDI) and rainfall anomaly index (RAI) were computed to show drought and flood tendencies in the region. Meanwhile, dry days (DD) and wet days (WD) were computed based on the definition as a day of the season with rainfall amounts less than 1.0 mm and greater than 1.0 mm, respectively. The CDI graphics indicated below-average rainfall during 1981–1987 and relatively wetter conditions during 1989–1995 for all stations in the region. Generally, seasonal rainfall declined over the first 27 years but an increasing trend in both MAM (March–April–May) and SOND (September–October–November–December) was observed in most stations during 2006–2017. The highly variable seasonal rainfall in the region is expected to impact the livelihoods of the communities. This study recommends that the use of tailor-made weather and climate information for planning economic development programs such as agriculture will play a critical role in improving the livelihood of the communities in the region.