中国极端降水事件的时空变化及趋势预测

Spatial-temporal Changes and Trend Predictions of Extreme Precipitation Events in China

基于622个站点的逐日降水数据,利用Mann-Kendall检验、Sen’s斜率和R/S分析等方法,探究了中国极端降水事件的时空变化特征及未来变化趋势。结果表明:(1)近60年来,中国极端降水量指数呈不显著增加趋势(p>0.05),最大一日降水量(RX1day)、最大五日降水量(RX5day)、强降水量(R95p)、总降水量(PRCPTOT)的增加速率分别为0.52、0.10、0.64和6.00 mm/10 a。极端降水强度指数(SDII)以0.13(mm/d)/10 a的速率显著增加(p<0.05);而极端降水日数指数呈不显著增加趋势(p>0.05),R20和R50的增加速率分别为0.13和0.06 d/10 a。(2)从分区来看,除持续湿润日数(CWD)外,极端降水事件的其他指数在华南、华中、西北和西南地区存在显著增加趋势(p<0.05),在东北和华北地区呈现显著减少趋势(p<0.05)。其中,RX1day在华南、华中、西北和西南地区的增加速率分别为0.62、0.52、0.21和0.49 mm/10 a,在东北和华北地区的减少速率分别为-0.48和-0.63 mm/10 a。而CWD在华南以外的地区均以低于0.05 d/10 a的速率显著减少(p<0.05)。(3)除R95p和PRCPTOT外,其余极端降水指数未来将延续历史变化趋势(H>0.5)。极端降水量指数和极端降水强度指数总体都将呈现增长趋势,且在华南、华中、西北和西南地区延续显著增加的趋势。而极端降水日数指数总体虽为增长趋势,但CWD仍将在华南以外的地区呈现持续性较强的下降趋势。研究结果可以为我国暴雨灾害预警与区域水资源利用提供参考。

Based on the daily precipitation data of 622 stations,the change and trend predictions of extreme precipitation events in China are explored by using the Mann-Kendall test,Sen’s slope,R/S analysis and other methods. The results show that:(1) Over the past 60 years,the extreme precipitation index in China has shown a no significant increase(p>0.05),and the maximum day precipitation(RX1day),the maximum five-day precipitation(RX5day),the heavy precipitation(R95p)and the total precipitation(PRCPTOT)have increased by0.52,0.10,0.64 and 6.00 mm/10 a,respectively. The extreme precipitation intensity index(SDII)increased significantly at a rate of 0.13(mm/d)/10 a(p<0.05),while the extreme precipitation day index shows no significant increase(p>0.05),with R20 and R50 increasing at rates of 0.13 and 0.06 d/10 a,respectively.(2) From the perspective of different regions,in addition to continuous wet days(CWD),other indices of extreme precipitation events show a significant increase in Southern,Central,Northwest and Southwest China(p<0.05),and a significant decrease in Northeast and Northern China(p<0.05). Thereinto,the increase rates of RX1day are 0.62,0.52,0.21 and 0.49 mm/10 a in Southern,Central,Northwest and Southwest China,respectively. The decrease rates of RX1day are-0.48 and-0.63 mm/10 a in Northeast and Northern China,respectively. Outside of Southern China,CWD decreases significantly at rates below 0.05 d/10 a(p<0.05).(3) In addition to R95p and PRCPTOT,other extreme precipitation indexes will continue their historical trend in the future(H>0.5). Both the extreme precipitation index and the extreme precipitation intensity index will show a sustained growth trend,and the significant increase will continue in Southern,Central,Northwest and Southwest China. Although the extreme precipitation daily index is generally an upward trend,the CWD will still show a strong downward outside southern China. The results can provide a reference for rainstorm disaster warnings and regional water resource utilization in China.