摘要
利用1998-2020年三峡库区35个测站的小时降水资料,围绕近23年三峡库区小时强降水(≥20 mm·h^(-1))和小时极端强降水(≥50 mm·h^(-1))的总降水量、频次、强度等指标,分析极端降水发生的时空变化特征,并对比分析2010年前后三峡小时极端降水变化特征。结果表明:1998年三峡库区小时强降水与极端强降水发生次数与强度均异常偏多。若剔除该年,1999-2020年小时强降水与极端强降水发生总频次均无显著变化趋势。近23年,小时强降水平均每年每站发生3.8次,大部分站点年均发生3.0~5.0次;小时极端强降水年均发生5.5次,大部分站点年均发生<0.25次,中部山区的建始-宣恩一带年均发生次数较多。2010年后年平均小时强降水量减小了10.4 mm,减小的区域主要发生在三峡库区西部的重庆地区,该区域年平均减小15.5 mm;总体有31.4%的站点年平均小时强降水量与发生次数均有所增加,湖北中部的建始-来凤一带增幅较为明显,邻近5站的年强降水雨量平均增加16.1 mm;强降水小时雨强显示增加特征站点占48.6%,强降水小时雨强增加的范围进一步增大。总体来看,三峡库区强降水增加的区域主要集中在东部更靠近坝址的区域,小时极端降水对汛期三峡来水的影响需要引起关注。
Using the hourly precipitation data from 35 stations in the Three Gorges Reservoir Region(TGRR)from 1998 to 2020,the spatial and temporal variation characteristics of extreme precipitation occurrence were an‐alyzed around the total amount,frequency and intensity of hourly heavy precipitation(≥20 mm·h^(-1))and hourly extreme heavy precipitation(≥50 mm·h^(-1))in the TGRR in the past 23 years.The characteristics of hourly ex‐treme precipitation variation in the TGRR before and after 2010 are also compared and analyzed.The results indi‐cate that the frequency and intensity of hourly heavy precipitation and extreme heavy precipitation in the TGRR were abnormally high in 1998.If this year is excluded,the total number of hourly heavy precipitation and ex‐treme heavy precipitation has no significant trend from 1999 to 2020.In recent 23 years,hourly heavy precipita‐tion occurs 3.8 times per station per year on average,and 3.0~5.0 times per year in most stations.The average annual occurrence of hourly extreme heavy precipitation is 5.5 times,and the average annual occurrence is less than 0.25 times in most stations.The average annual occurrence is more in the Jianshi-Xuanen area in the central mountainous area.The spatial distribution of annual mean heavy precipitation and hourly heavy precipitation in the TGRR is quite different.After 2010,the annual mean hourly heavy precipitation decreased by 10.4 mm,mainly in Chongqing area in the west of the TGRR,with an annual mean decrease of 15.5 mm.The annual mean hourly heavy precipitation and its occurrence frequency increased at 31.4%stations,and the increase was more obvious in the Jianshi-Laifeng area in central Hubei Province,and the annual heavy precipitation at five sta‐tions increased by 16.1 mm on average.And formed the distribution state with the beginning of construction as the center.The"increase and decrease"of the average number of extreme heavy precipitation for many years be‐fore and after 2010 presents an alternating southwest-northeast belt distribution.The average number of extreme precipitation in most regions remained at 0.0~0.5,with little change on the whole.The stations with increasing characteristics of heavy rainfall intensity accounted for 48.6%,and the increasing range of heavy precipitation rain intensity was further expanded.In the Wulong-Changyang area,the rainfall intensity of hourly heavy precipi‐tation increased while the heavy precipitation decreased.On the whole,the increase of heavy precipitation in the TGRR is mainly concentrated in the eastern area closer to the reservoir area,and the influence of hourly extreme precipitation on incoming water in flood season needs to be paid attention to.
作者
张天宇
王雨潇
孙营营
刘波
蒋佳怡
ZHANG Tianyu;WANG Yuxiao;SUN Yingying;LIU Bo;JIANG Jiayi(Chongqing Climate Center,Chongqing 401147,China;College of Hydrology and Water Resources,Hohai University,Nanjing 210098,Jiangsu,China)
出处
《高原气象》
CSCD
北大核心
2023年第1期108-115,共8页
Plateau Meteorology
基金
中国长江三峡集团有限公司项目(0704182)
三峡局地气候监测项目(SK2021031)
国家自然科学基金项目(41875111,40975058)
中国气象局创新发展专项(CXFZ2022J031,CXFZ2021J018)
重庆市气象局业务技术攻关项目(YWJSGG-202206)。
关键词
三峡库区
小时强降水
小时极端强降水
年代际变化
Three Gorges Reservoir Region
hourly heavy precipitation
hourly extreme heavy precipitation
decadal variation
