Probability distribution characteristics of summer extreme precipitation in Xinjiang, China during 1970–2021

Abstract

Based on the daily precipitation data of 96 stations in Xinjiang, China, from 1970 to 2021, the trend of summer extreme precipitation indices and their regional characteristics are analyzed. The generalized extreme value (GEV) model is used to investigate the probability distribution characteristics of summer extreme precipitation indices in northern, southern, and eastern Xinjiang. The results show that (1) The summer maximum 1-day precipitation (RX1day) and maximum 5-day precipitation (RX5day) of most stations in Xinjiang showed an increasing trend, while the summer consecutive dry days (CDD) showed a decreasing trend. (2) The climatology (mean intensity) of RX1day, RX5day, and CDD at most stations in northern Xinjiang were more than 10 mm, more than 15 mm, and less than 25 days, respectively, while those at most stations in southern and eastern Xinjiang were less than 10 mm, less than 15 mm, and more than 25 days. The regional averaged climatology and inter-annual variability of RX1day/RX5day (CDD) in southern and eastern Xinjiang were smaller (larger) than that in northern Xinjiang. (3) The 20-year return level (RL20) of RX1day, RX5day, and CDD at stations in northern Xinjiang were 19.38–56.57 mm, 28.05–70.91 mm, and 22.51–51.05 days, respectively. The RL20 of RX1day, RX5day, and CDD at stations in southern Xinjiang were 21.31–46.07 mm, 23.99–72.89 mm, and 14.94–89.80 days, respectively. The RL20 of RX1day, RX5day, and CDD at stations in eastern Xinjiang were 8.89–36.36 mm, 10.13–50.66 mm, and 26.75–92.00 days, respectively. Compared with northern Xinjiang, there were lesser RX1day and RX5day events, with weaker intensity and smaller variability in southern and eastern Xinjiang. And the CDD events were opposite.

Dynamic Changes in Vegetation Ecological Quality in the Tarim Basin and Its Response to Extreme Climate during 2000–2022

“…Hu observed a declining trend in the number of overall cumulative dry days (CDD) in Xinjiang [76]. However, in this study, the CDD showed a rising tendency, which contradicts the general pattern observed in Xinjiang, and compared to northern Xinjiang, there are fewer RX1d and RX5d events with weaker intensity in the Tarim Basin, while the CDD events are the opposite [77]. Under RCP4.5 and RCP8.5 scenarios, Zhang concluded that the CDD in Central Asia is expected to increase slightly in the 21st century [78], and persistent drought in southern Xinjiang is also expected to intensify [79], aligning with the conclusions drawn from this research.…”

Comparison of Flash Drought and Traditional Drought on Characteristics and Driving Forces in Xinjiang

“…Over the period from 1960 to 2021, the average annual temperature in Xinjiang ranged from −20 • C to 17 • C, with an average annual precipitation level of 156 mm. Precipitation in northern Xinjiang generally surpasses that in the southern region, and mountainous areas receive greater amounts of precipitation compared to the basin areas [40][41][42].…”