Impacts of climate change on extreme precipitation in the upstream of Chushandian Reservoir, China

Abstract

Analysis of trends in extreme precipitation events within a basin is essential to reliably predict future changes and to inform adaptation strategic planning. Based on daily data from eight stations in the upper basin of Chushandian Reservoir from 1957 to 2017, and Multi-model outputs from four Global Climate Models in CMIP6, we calculated the extreme precipitation index. Mann-Kendall method and linear trend analysis were used to examine the spatial and temporal variability of the extreme precipitation index. The results show that there is a clear downward trend in precipitation and precipitation intensity from 1957 to 2017 (represented by RX1day, RX5day, R10 mm, R20 mm, and SDII), and an upward trend in the annual scales of R95p, R99p, CWD, and CDD. The trend of the extreme precipitation index (represented by PRCPTOT, R20 mm, R95p, and SDII) in future periods is decreasing in 2020–2050 and then increasing in 2060–2100, with a significant increasing trend after the 2060s. These findings indicate that total precipitation, the frequency, and persistence of extreme precipitation are on the increase, and the future situation of extreme precipitation is severe, especially in autumn, followed by summer. HIGHLIGHTS There is a significant downward trend in the total amount and intensity of extreme precipitation in the study area in 1957–2017.; Global warming tends to increase extreme precipitation in terms of frequency and intensity.; Extreme precipitation value domains predicted by climate change are noticeably higher than historical levels.;

Keywords

• chushandian reservoir
• climate change
• cmip6
• extreme precipitation index