Flooding in the Yellow River Basin, China: Spatiotemporal patterns, drivers and future tendency

The Yellow River Basin (YRB) in China. This study is devoted to simulating flood changes with return periods of 10, 20, 30, 50, 100 and 200 years under three Representative Concentration Pathways (RCPs) using CaMa-Flood models, and examining the drivers. In the historical period (1961–2005), the middle and lower YRB and specifically the Wei River Basin (WRB) (a tributary of the middle YRB) are dominated by higher flood risks with once-in-200-year flood magnitude of 9989.63 m3/s. Under climate change scenarios, the relative change in the once-in-100-year flood magnitude increased from 125.0% (RCP2.6) to 204.9% (RCP8.5) during the historical period (1961–2005) to the long-term period (2076–2092). The historical flood-prone regions were more susceptible to increased flood magnitude. Meanwhile, the area with increased flood risks ranged from 73.6% to 95.2% in the YRB. Increased flood magnitude was typically related to lengthened return interval of floods under the RCP2.6 and RCP6.0 scenarios, while decreased flood magnitude was commonly linked to increased return intervals under the RCP8.5 scenarios. Notably, we observed higher correlations between 7-day maximum precipitation and floods compared to those between daily maximum precipitation, soil moisture, and floods. Co-occurrences between flood events and hydrometeorological extremes were higher in the upper and middle YRB.