Characteristics of Extreme Precipitation in the Three Gorges Reservoir Region During 1961～2020
Extreme precipitation plays an important role in the regulation,storage,and flood control of the Three Gorges Reservoir.The changing characteristics of extreme precipitation in the Three Gorges Reservoir region(TGRR)under the background of global warming are worth studying.Based on the observational precipitation data of 33 meteorological stations in TGRR from 1961 to 2020,the spatial-temporal characteristics of extreme precipitation events for hourly,daily and consecutive precipitation in TGRR were analyzed.The results showed that the spatial distribution of the maximum hourly precipitation,daily precipitation,and consecutive precipitation was greater in southeastern TGRR than in other areas,and less in southwestern and northeastern TGRR than in other areas.However,the spatial distributions of the trend of the annual maximum hourly precipitation,daily precipitation and process precipitation were different from each other.The threshold values of extreme hourly precipitation,daily precipitation,and consecutive precipitation events in TGRR were all large in eastern TGRR and small in western TGRR.The maximum threshold value of daily precipitation and consecutive precipitation extreme event occurred at Hefeng in Hubei province.Under the background of global warming,the frequency of extreme daily precipitation events in TGRR increased in summer,especially in June and July.The distribution of monthly frequency of extreme consecutive precipitation events was bimodal during 1961～1990,with the main peak in June and secondary peak in September,respectively.During 1991～2020,the monthly frequency of extreme consecutive precipitation events was more concentrated in summer,with the peak in June.The annual frequency of extreme hourly precipitation,daily precipitation events showed an increasing trend,while that of extreme consecutive precipitation events had a decreasing trend during 1961～2020.However,the increasing trends were found for all since 2001,and the trends of extreme hourly precipitation and daily precipitation events were significant at the significance level of 0.05.Our findings suggested that more attention should be paid to extreme precipitation observation,which may raise the risk of rainstorm and flood disasters in TGRR,in flood seasons.
Three Gorges Reservoir Areaextreme precipitation eventthreshold value,long-term change
NETL
NSTL
万方数据
