Recent changes in extreme floods across multiple continents

Research output: Contribution to journalArticlepeer-review

Authors

  • Wouter R. Berghuijs
  • Emma E. Aalbers
  • Joshua Larsen
  • Ralph Trancoso
  • Ross A. Woods

Colleges, School and Institutes

External organisations

  • BRISTOL UNIVERSITY
  • ETH Zurich
  • Royal Netherlands Meteorological Institute
  • Vrije Universiteit Amsterdam
  • University of Queensland
  • University of Lausanne

Abstract

Analyses of trends in observed floods often focus on relatively frequent events, whereas changes in rare floods are only studied for a small number of locations that have exceptionally long observational records. Understanding changes in rare floods is especially relevant as these events are often most damaging and influence the design of major structures. Here, we provide an assessment of changes in the largest flood events (∼0.033 annual exceedance probability) observed during the period 1980-2009 for 1744 catchments located in Australia, Brazil, Europe and the United States. The occurrence of rare floods in spatial aggregate shows strong temporal variability and peaked around 1995. During the 30 year period, there are overall increases in both the frequency and magnitude of extreme floods. These increases are strongest in Europe and the United States, and weakest in Brazil and Australia. Physical causes of the reported short-term variability and longer-term changes in extreme floods currently remain elusive, because the key drivers vary between catchments. Nonetheless, this approach provides the basis for a more spatially representative assessment of changes in extreme flood occurrence.

Details

Original languageEnglish
Article number114035
JournalEnvironmental Research Letters
Volume12
Issue number11
Early online date24 Aug 2017
Publication statusPublished - 16 Nov 2017

Keywords

  • flood, global hydrology, hydro-climate, natural hazard