Publication Date:
2023-01-25
Description:
Drought poses significant challenges to global water security in a warming world. A global‐scale synthesis of the multivariate drought risk considering interdependencies between drought attributes across disparate climate regimes is still lacking. Leveraging precipitation and streamflow observations of 270 large catchments over the globe, we show that multivariate drought hazard amplifies significantly (at ∼65–76% of catchments) considering dependence between drought duration and severity. A signifying nature of this amplification (A) is the power‐law scaling with dependence metric (A∝τλ;λ=5−12; $A\propto {\tau }^{\lambda };\,\lambda =5-12;$ where τ and λ are Kendall's correlation and the scaling exponent), revealing current approaches considering drought attributes as independent or linearly dependent will severely underestimate likelihood of extreme droughts. Furthermore, we find disparate responses in the multivariate imprints of meteorological to hydrological droughts across climate types, with strengths varying from large to modest in Tropics and Mid‐latitudes, which indicates weaker overlap between rain‐deficit and streamflow droughts. In contrast, a strong overlap in multivariate hazards of rain‐deficit and streamflow droughts is apparent across transitional Subtropics. Our study highlights the relevance of accounting for multivariate aspects of drought hazards to inform adaptation to water scarcity in a changing climate.
Description:
Plain Language Summary:
The world's large river basins support a huge population and diverse ecosystems. A growing body of the literature suggests holistic risk management requires a “multivariate event perspective” to analyze interacting drought attributes rather than each of these drivers in isolation. Using the gauge‐based observational framework, we show a robust amplification in multivariate drought hazard and this response co‐vary among distinct climate regimes. Our multivariate hazard framework shows a contrasting response in multivariate imprints (or degree of overlap) of rain‐deficit (drivers) to streamflow (response)‐droughts across disparate climate regimes for milder and extreme categories of droughts; from substantial regional variations in multivariate drought hazard in tropics and mid‐latitudes, revealing a weak imprint between drought types. In contrast, the transitional subtropics show a modest variation in the multivariate imprint of drought types, indicating stronger imprint. We emphasize that failure to account for nonlinear interactions among interacting drought attributes will severely underestimate the extreme drought hazard, jeopardizing the adequacy of resilient water infrastructure design. The insights will aid in adaptation to extreme droughts under global warming.
Description:
Key Points:
Global synthesis of multivariate drought imprints between rain‐deficit and streamflow droughts.
Observational assessment showed strong amplifications in bivariate drought hazards to dependence.
Strong imprints between rain‐deficit and streamflow droughts in transitional sub‐tropics.
Description:
Department of Science and Technology, Ministry of Science and Technology, India
http://dx.doi.org/10.13039/501100001409
Description:
German Academic Exchange Service New Delhi
http://dx.doi.org/10.13039/501100001650
Description:
Science and Engineering Research Board
http://dx.doi.org/10.13039/501100001843
Description:
Indian Institute of Technology Kharagpur
http://dx.doi.org/10.13039/501100008984
Description:
Deutscher Akademischer Austauschdienst
http://dx.doi.org/10.13039/501100001655
Description:
https://portal.grdc.bafg.de/applications/public.html?publicuser=PublicUser
Description:
https://opendata.dwd.de/climate_environment/GPCC/html/download_gate.html
Keywords:
ddc:551.5
;
hydrological drought
;
meteorological drought
;
multivariate drought hazard
Language:
English
Type:
doc-type:article
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