Mighty Floods of the Nile River During Warmer and Wetter Climates

Typography

Global warming as well as recent droughts and floods threaten large populations along the Nile Valley.

Global warming as well as recent droughts and floods threaten large populations along the Nile Valley. Understanding how such a large river will respond to an invigorated hydrological cycle is therefore a pressing issue. Insights can be gained by studying past periods with wetter and warmer conditions, such as the North African Humid Period eleven to six thousand years ago. A research team of the German Research Centre for Geosciences GFZ, led by Cécile Blanchet, together with colleagues at the University of Innsbruck (Austria) and the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (Germany) analysed a 1,500 year long annually-laminated sediment core. The study was published today in Nature Geoscience.

It reveals that wetter climates led to very strong and weak floods and a highly instable river system, which may have rendered the Nile valley uninhabitable. Although intensified, flood variability was paced by similar climatic forcing as today, operating on annual – like El Niño – to multi-decadal timescales. This suggests that the occurrence of such extreme events might be predictable helping to reduce risks for local populations.

Read more at: GFZ Geoforschungszentrum Potsdam, Helmholtz Centre

Waterfall on the Blue Nile river in West Gojjam, Amhara Region, Ethiopia. This region is threatened by natural hazards such as flooding due to climate change. (Photo Credit: CCBY 2.0 Giustino)