Projected changes in droughts and extreme droughts in Great Britain strongly influenced by the choice of drought index

Abstract ∘ C above pre-industrial levels. The projected increases in drought frequency and extent are far greater based on the SPEI than based on the SPI. Importantly, compared with droughts of all intensities, isolated extreme droughts are projected to increase far more with respect to frequency and extent and are also expected to show more pronounced changes in the distribution of their event durations. Further, projected intensification of the seasonal cycle is reflected in an increasing occurrence of years with (extremely) dry summers combined with wetter-than-average winters. Increasing summer droughts also form the main contribution to increases in annual droughts, especially using the SPEI. These results show that the choice of atmospheric drought index strongly influences the drought characteristics inferred from climate change projections, with a comparable impact to the uncertainty from the climate model parameters or the warming level; therefore, potential users of these indices should carefully consider the importance of potential evapotranspiration in their intended context. The stark differences between SPI- and SPEI-based projections highlight the need to better understand the interplay between increasing atmospheric evaporative demand, moisture availability and drought impacts under a changing climate. The region-dependent projected changes in drought characteristics by two warming levels have important implications for adaptation efforts in GB, and they further stress the need for rapid mitigation.

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch

References and Relationships

• Bibliographic citation: Projected changes in droughts and extreme droughts in Great Britain strongly influenced by the choice of drought index ; volume:27 ; number:5 ; year:2023 ; pages:1151-1171 ; extent:21 ; Hydrology and earth system sciences ; 27, Heft 5 (2023), 1151-1171 (gesamt 21)

Contributors, Places and Time

• Creator: Reyniers, Nele ; Osborn, Timothy J. ; Addor, Nans ; Darch, Geoff

Further information

• DOI: 10.5194/hess-27-1151-2023
• URN: urn:nbn:de:101:1-2023033005423034037160
• Rights: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 14.08.2025, 11:02 AM CEST