Spatiotemporal variability of drought and affected croplands in the horn of Africa

The Horn of Africa (HOA) is frequently plagued by severe droughts, significantly affecting food security, particularly in less developed and rapidly population-growing regions. This study aims to provide crucial insights into the long-term spatiotemporal patterns of drought and their impact on croplands in the HOA. The findings will contribute to developing effective early warning systems to mitigate drought-related risks, ensure sustainable water and food production and alleviate the consequences of droughts in the region. To achieve this, the study estimates the standardised precipitation evapotranspiration index (SPEI) for different time scales (3, 6 and 12 months). Over the previous 120 years (1901-2020), it examines the geographical and temporal trends of drought frequency, intensity, length, affected areas, and the extent of agricultural land impacted. The results reveal that moderate droughts of varying duration occur approximately once every 5 years throughout most of the HOA, while severe droughts occur once every 10 to 15 years. On the contrary, extreme droughts are predominantly observed in the eastern part of the HOA. The study also highlights a gradual decline in atmospheric water availability in the region. There has been increased rainfall variability in recent decades compared to the early twentieth century, leading to a rise in droughts. The analysis indicates a significant increase in 3-month droughts, particularly in the eastern part of the HOA, which historically has been more susceptible to droughts. Before 1940, HOA did not experience severe 3-month droughts, but they have become more common throughout the region since 1981. Similar trends have been observed for droughts of 6 and 12 months. Furthermore, the frequency of croplands affected by droughts of different durations has nearly doubled between 1981 and 2020 compared to 1901-1940. These findings shed light on the increasing risk of drought in the HOA and emphasise the need for proactive measures to address the challenges posed by droughts.