Characterization of changes in extreme precipitation events in Yuanzhou District, Guyuan City, 1957–2016

Abstract

To further strengthen the scientific basis for water resources management and drought prevention in Yuanzhou District. This paper analyzes the trend, sudden change, and periodic change of extreme precipitation events in Yuanzhou District, Guyuan City, based on daily precipitation data from 1957 to 2016, and selects eight extreme precipitation indices using linear fitting, the Mann-Kendall mutation test, and Morlet wavelet analysis. The results showed that: (1) The trends in each of the extreme precipitation indices in the Yuanzhou District varied from 1957 to 2016, with a non-significant decrease in the number of moderate rain days (R10), heavy rain days (R20), 5-day maximum precipitation (RX5day), heavy precipitation (R95p), annual precipitation (PRCPTOT) and continuous dry days (CDD), but a non-significant increase in 1-day maximum precipitation (RX1day) and continuous wet days (CWD). (2) The abrupt changes in each extreme precipitation index from 1957 to 2016 were variable in the Yuanzhou District, with only R10 and R20 showing significant abrupt changes in 1968 and 1960, respectively. (3) The main oscillation cycle of the precipitation index was consistent across the extremes in the Yuanzhou District of Guyuan City from 1957 to 2016, with 23 a being the first main control cycle. The changing characteristics of extreme precipitation in the Yuanzhou District of Guyuan City have remained largely stable, but care must still be taken to guard against extreme precipitation events.