TY - JOUR
T1 - Impact of precipitation and increasing temperatures on drought trends in eastern Africa
AU - Kew, Sarah F.
AU - Philip, Sjoukje Y.
AU - Hauser, Mathias
AU - Hobbins, Mike
AU - Wanders, Niko
AU - Jan Van Oldenborgh, Geert
AU - Van Der Wiel, Karin
AU - Veldkamp, Ted I.E.
AU - Kimutai, Joyce
AU - Funk, Chris
AU - Otto, Friederike E.L.
PY - 2021/1/6
Y1 - 2021/1/6
N2 - In eastern Africa droughts can cause crop failure and lead to food insecurity. With increasing temperatures, there is an a priori assumption that droughts are becoming more severe. However, the link between droughts and climate change is not sufficiently understood. Here we investigate trends in long-term agricultural drought and the influence of increasing temperatures and precipitation deficits. Using a combination of models and observational datasets, we studied trends, spanning the period from 1900 (to approximate pre-industrial conditions) to 2018, for six regions in eastern Africa in four drought-related annually averaged variables: soil moisture, precipitation, temperature, and evaporative demand (E0). In standardized soil moisture data, we found no discernible trends. The strongest influence on soil moisture variability was from precipitation, especially in the drier or water-limited study regions; temperature and E0 did not demonstrate strong relations to soil moisture. However, the error margins on precipitation trend estimates are large and no clear trend is evident, whereas significant positive trends were observed in local temperatures. The trends in E0 are predominantly positive, but we do not find strong relations between E0 and soil moisture trends. Nevertheless, the E0 trend results can still be of interest for irrigation purposes because it is E0 that determines the maximum evaporation rate. We conclude that until now the impact of increasing local temperatures on agricultural drought in eastern Africa is limited and we recommend that any soil moisture analysis be supplemented by an analysis of precipitation deficit.
AB - In eastern Africa droughts can cause crop failure and lead to food insecurity. With increasing temperatures, there is an a priori assumption that droughts are becoming more severe. However, the link between droughts and climate change is not sufficiently understood. Here we investigate trends in long-term agricultural drought and the influence of increasing temperatures and precipitation deficits. Using a combination of models and observational datasets, we studied trends, spanning the period from 1900 (to approximate pre-industrial conditions) to 2018, for six regions in eastern Africa in four drought-related annually averaged variables: soil moisture, precipitation, temperature, and evaporative demand (E0). In standardized soil moisture data, we found no discernible trends. The strongest influence on soil moisture variability was from precipitation, especially in the drier or water-limited study regions; temperature and E0 did not demonstrate strong relations to soil moisture. However, the error margins on precipitation trend estimates are large and no clear trend is evident, whereas significant positive trends were observed in local temperatures. The trends in E0 are predominantly positive, but we do not find strong relations between E0 and soil moisture trends. Nevertheless, the E0 trend results can still be of interest for irrigation purposes because it is E0 that determines the maximum evaporation rate. We conclude that until now the impact of increasing local temperatures on agricultural drought in eastern Africa is limited and we recommend that any soil moisture analysis be supplemented by an analysis of precipitation deficit.
UR - http://www.scopus.com/inward/record.url?scp=85099015419&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85099015419&partnerID=8YFLogxK
U2 - 10.5194/esd-12-17-2021
DO - 10.5194/esd-12-17-2021
M3 - Article
AN - SCOPUS:85099015419
SN - 2190-4979
VL - 12
SP - 17
EP - 35
JO - Earth System Dynamics
JF - Earth System Dynamics
IS - 1
M1 - 12
ER -