Global drought-flood abrupt alternation: Spatio-temporal patterns, drivers, and projections

<p>The spatiotemporal patterns and driving factors of drought-flood abrupt alternations (DFAA) have been investigated across several regional and watershed scales; however, comprehensive examination at the global scale is lacking. Here, we employed the long period drought-flood abrupt change index (LDFAI), derived from an ensemble of 40 output datasets from eight Coupled Model Intercomparison Project phase 6 (CMIP6) models, to assess the spatiotemporal patterns, drivers, and future projections of global DFAA. The results indicate that DFAA are influenced by various anthropogenic forcings, and greenhouse gas emissions exert the most significant impact. The changes in the intensity of global DFAA (1950–2014), attributed to natural forcing (NAT), anthropogenic aerosols (AER), and greenhouse gas (GHG) forcing, accounted for 5.65%, 14.57%, and 33.55%, respectively. The rates of change of the DFAA intensity under shared socioeconomic pathways (SSPs) from 2014 to <styled-content style-type="number">2100</styled-content> were estimated to be 21.73% (SSP1-2.6), 45.37% (SSP2-4.5), 63.1% (SSP3-7.0), and 69.51% (SSP5-8.5). This means that under high radiative forcing, the regional rivalry and fossil-fuel development models will lead to a significant increase in DFAA. These findings can aid in the development of global adaptive policies related to DFAA.</p>