Assessment of drought patterns in Uganda: A case study of Gulu district.

Abstract

Drought has many negative related impacts and has also been identified as the most challenging climatic hazard and a food threat in Uganda. This study characterizes both meteorological and agricultural drought and also uses the Markov chain model to a give a prediction of the future drought occurrence probabilities in Gulu district. Meteorological drought was analysed at various time scales of 3-, 6-, 9-, and 12 months using the Standard precipitation index (SPI) for a period of 1990-2019. Agricultural drought was characterized using the NDVI based drought anomalies for a period of 2010-2019 with 2020 as the base year. Results indicated that Gulu district experienced alternate moderately dry, severely dry and extremely dry conditions that occurred in various months in the period of study. The results further indicated that in 2020, the month of December was the most affected by agricultural drought with over 80% of Gulu district having NDVI anomaly values below 0. The Markov chain model indicated that, for the study period (1990-2019), the mean duration of drought was 4months and that the likelihood of future drought occurrence in Gulu is 15.54%. The mapping of agricultural drought using the SPI index at various time scales, the review of the agricultural drought that occurred in 2020 as well as the future drought occurrence probabilities in Gulu district can be a start-up for decision makers in the study area and in the country to establish intervention and mitigation plans.