中国西北地区东部近546年干旱事件特征分析  

Characteristics of droughts in eastern Northwest China over the past 546 years

作　　者：王芝兰[1] 奚立宗[2] 李耀辉[1] 董安祥[1] WANG Zhilan;XI Lizong;LI Yaohui;DONG Anxiang(Insitute of Arid Meteorology,China Meteorological Administration/Key Laboratory of Arid Climatic Change and Disaster Reduction,Gansu Province/Key Laboratory of Arid Climate Change and Disaster Reduction,China Meteorological Administration,Lanzhou 730020,China;Gansu Provincial Meteorological Administration,Lanzhou 730020,China)

机构地区：[1]中国气象局兰州干旱气象研究所/甘肃省干旱气候变化与减灾重点实验室/中国气象局干旱气候变化与减灾重点实验室,兰州730020 [2]甘肃省气象局,兰州730020

出　　处：《气象学报》2020年第1期72-85,共14页Acta Meteorologica Sinica

基　　金：公益性行业(气象)科研专项(GYHY(QX)201506001-1);国家自然科学基金项目(41975111)

摘　　要：以西北地区东部的17个代表站1470-2008年的旱涝等级资料和1958-2015年5-9月气象站降水量数据为基础,建立了546年中国西北地区东部旱涝等级序列,采用经验正交函数分解、滑动t检验等统计方法,对其干湿演变规律进行分析,详细讨论了546年极端干旱事件及干旱持续性特征.结果表明:旱涝等级资料能够较好地反映西北地区东部干旱变化的时、空特征;在百年尺度上,20世纪发生旱、偏旱最为频繁,且高值区位于宁夏及陕北;干旱尺度因子的空间分布表明宁夏东部及陕北地区的干旱持续性相对较强,陇南及陕西南部地区的干旱持续性较差;空间范围较大且强度较大的重大干旱事件对干旱的持续发生起重要作用,历史上发生在1470-1500年和1910-1940年的两次西北地区东部百年甚至两百年一遇的极端干旱事件,对该地区干旱持续性的影响较为显著.Based on the drought/flood grade data for 17 stations during 1470−2008 and precipitation from May to September during 1958−2015 in eastern Northwest China,the sequence of drought/flood grade during the period of 1470−2015 has been established.Spatial and temporal characteristics of the drought variation are analyzed;extreme drought events occurred during the 546 years and the characteristics of drought persistence are discussed in detail.The results show that the drought/flood grade data can well reflect the spatial and temporal characteristics of drought changes over eastern Northwest China.On the century scale,drought occurred most frequently in the 20th century,and the areas of high occurrence frequency are found in Ningxia and Northern Shaanxi.Drought scale factors indicated that the drought persistence in eastern Ningxia and northern Shaanxi was relatively long.Those drought events that covered a large area with high intensity play an important role in the persistence of drought.The drought persistence was significant during periods of 1470−1500 and 1910−1940,when two"one-hundred-year"and even"two-hundred-year"extreme drought events occurred over eastern Northwest China.

关 键 词：长时间序列 干旱持续性 西北地区东部 

分 类 号：P467[天文地球—大气科学及气象学]