Long-term variability in hydrological droughts and floods in sub-Saharan Africa: New perspectives from a 65-year daily streamflow dataset

Job Ekolu, Bastien Dieppois, Moussa Sidibe, Jonathan M. Eden, Yves Tramblay, Gabriele Villarini, Dhais Peña-Angulo, Gil Mahé, Jean Emmanuel Paturel, Charles Onyutha, Marco van de Wiel

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


Understanding hydrological variability is of crucial importance for water resource management in sub-Saharan Africa (SSA). While existing studies typically focus on individual river basins, and suffer from incomplete records, this study provides a new perspective of trends and variability in hydrological flood and drought characteristics (frequency, duration, and intensity) across the entire SSA. This is achieved by: i) creating a 65-year long, complete daily streamflow dataset consisting of over 600 gauging stations; ii) quantifying changes in flood and drought characteristics between 1950 and 2014; iii) evaluating how decadal variability influences historical trends. Results of daily streamflow reconstructions using random forests provide satisfactory performance over most of SSA, except for parts of southern Africa. Using change-point and trend analyses, we identify-three periods that characterise historical variations affecting hydrological extremes in western and central Africa, and some parts of southern Africa: i) the 1950s–60s and after the 1980s–90s, when floods (droughts) tend to be more (less) intense, more (less) frequent and more (less) persistent; and ii) the 1970s–80s, when floods (droughts) are less (more) intense, less (more) frequent and less (more) persistent. Finally, we reveal significant decadal variations in all flood and drought characteristics, which explain aperiodic increasing and decreasing trends. This stresses the importance of considering multiple time-periods when analysing recent trends, as previous assessments may have been unrepresentative of long-term changes.

Original languageEnglish (US)
Article number128359
JournalJournal of Hydrology
StatePublished - Oct 2022
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Water Science and Technology


  • Daily streamflow
  • Decadal to multidecadal variability
  • Gap-filling
  • Hydrological drought and floods
  • Sub-Saharan Africa
  • Trend


Dive into the research topics of 'Long-term variability in hydrological droughts and floods in sub-Saharan Africa: New perspectives from a 65-year daily streamflow dataset'. Together they form a unique fingerprint.

Cite this