Copula-based risk evaluation of global meteorological drought in the 21st century based on CMIP5 multi-model ensemble projections

Chuanhao Wu, Pat J.-F. Yeh, Yi-Ying Chen, Wenhan Lv, Bill X. Hu, Guoru Huang

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21 Citations (Scopus)

Abstract

Climate warming is expected to have significant impacts on the global hydrologic cycle, including changes in precipitation-induced extremes such as droughts. Using 28 CMIP5 global climate models (GCMs), this study presents a global-scale analysis of the joint return periods (T) of meteorological drought characteristics (duration D, severity S, and peak P) at the 6- and 12-month scales under the Representative Concentration Pathways scenarios RCP2.6 and RCP4.5. The D, S, and P estimated based on the Runs theory are used to calculated from the Standardized Precipitation Index (SPI) at the global 1° × 1° grids. Six marginal probability distributions are used to fit S, P and D, whereas three Archimedean copula functions (Clayton, GH and Frank) are used to estimate T for the paired drought characteristics (S-D, P-D and S-P). Large spatial variability is found globally in the best-fitted copulas for the paired drought characteristics, with the Frank (Frank and GH) of the largest global percentage for SPI6 (SPI12). Relative to the baseline (1971–2000), the T of the paired drought characteristics above the moderate drought (S > 1, P > 1 and D > 3) is projected to decrease mostly in North America and Asia (<0.22-year) during the 2021–2050 near-future (NF) period, and in South America and Australia (<0.47-year) during the 2071–2100 far-future (FF) period. In contrast, an increase in T is projected during NF (<3-year) mostly in South America and Australia, and during FF (<49-year) mostly in Asia, Europe and North America. Furthermore, a larger increase in T is projected under higher RCP and at longer timescales. Our results suggest a generally nonlinear response of the projected drought risk changes to anthropogenic forcing during the 21st century.

Original languageEnglish
Article number126265
Number of pages14
JournalJournal of Hydrology
Volume598
DOIs
Publication statusPublished - Jul 2021

Keywords

  • CMIP5
  • Copula
  • Global projection
  • Joint return period
  • Meteorological droughts
  • SPI

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