Spatiotemporal characteristics of extreme precipitation in the Yellow River basin based on CMIP6

Due to global warming, the risk of extreme precipitation disasters has increased． This has seriously affected people’s life safety and posed serious threat to regional economic development． The Yellow River basin is an important ecological barrier and economic zone． Promoting the ecological protection and high-quality development in the Yellow River basin has become China’s national strategy． Therefore, we studied the past and future characteristics of extreme precipitation events in the Yellow River basin． From 1975 to 2014, all extreme precipitation indices showed decreasing trends from southeast to northwest． On the temporal scale, almost all extreme precipitation indices (exceptions: total wet-day precipitation, number of heavy precipitation days and max 5-day precipitation amount) showed insignificant increasing trends． Extreme precipitation events are few and far between． Extreme precipitation index showed a significant upward trend from 2015 to 2100, spatial distribution pattern of multi-annual mean value of extreme precipitation index was similar to past historical period． With increased emission, greater radiation force, area of extreme precipitation index continued to increase significantly． Under SSP1-2.6 and SSP2-4.5 scenarios, area with significant increase concentrated in the southwest． Under SSP3-7.0 and SSP5-8.5 scenarios, extreme precipitation in most of the eastern region (exception: southwest region) showed a significant increase． In addition to annual precipitation, other extreme precipitation index showed a significant decreasing trend, concentrating in Gansu and Qinghai provinces． Annual average precipitation in the Yellow River basin in four seasons shows an increasing trend, and there is a trend of wet weathers in different seasons． Index of max1-day and max 5-day precipitation amounts in all regions other than Ningxia showed varied increasing trend in the four seasons． Peak max 1-day and max 5-day precipitation largely concentrated in July． Rainstorm and flood disasters in the future will also likely to occur in the summer in the Yellow River basin．