文献记录的河西地区小冰期旱涝变化及其机制探讨  

Variation of D/F records in historical documents of Hexi region during LIA and its mechanism

作　　者：董惟妙[1] 安成邦[1] 赵永涛[1] 李虎[1] 

机构地区：[1]兰州大学西部环境教育部重点实验室,甘肃兰州730000

出　　处：《干旱区地理》2012年第6期946-951,共6页Arid Land Geography

基　　金：国家自然科学基金(40871006);国家自然科学基金委员会基础科学人才培养基金(J0730536)资助

摘　　要：基于文献资料重建了河西地区AD 1436-1949旱涝灾害等级序列,结果表明所研究的500余年内河西地区大体出现三次明显的干旱时段,分别为AD 1460-1539、AD 1616-1665和AD1907-1949,而AD 1725-1748以及AD 1879-1906则为相对湿润时期。重建的旱涝等级序列与毗邻祁连树轮记录的干湿变化存在高度一致的对应关系;将其与NAO指数对比发现,冷期NAO高指数年对应旱灾多发,NAO低指数年对应涝灾多发。Plenty of historical documents was used in this paper to reconstruct the droughts and floods sequence of Hexi region during AD 1436 - 1946, which is usually called the Little Ice Age （LIA）. The climatic related records of this region were collected and classified into 5 levels year by year using traditional classification methods, from 1 to 5, each was defined as wet （humid）, mildly wet （humid）, normal, mildly dry and dry, respectively. The se- ries of dry and wet levels comprises the annual drought/flood （D/F） sequence and ten-year mean value of D/F se- quence, both of which highly reflect the precipitation variation. It is revealed that during the following periods, there happened much more drought events, such as, AD 1460 - 1539, AD 1616 - 1665 and AD 1907 - 1949, while droughts happened during the third and fourth ten years of the 20th century were the most severe ones. Flood events were more often during AD 1725 - 1748 and AD 1879 - 1906. Compared with the tree-ring data of the Qil- Jan Mountains nearby, the result indicates that both of them are highly consistent. Flood events correlate to relative- ly high tree-ring index, while drought events have a good respond to low tree-ring index, which makes the recon- struction of the D/F variation for Hexi region reliable. Added with the North Atlantic Oscillation （NAO） index, it turned out that during the relatively cool period of LIA, NAO played the leading role in precipitation of Hexi region with the high NAO index going along with drought events while low one going with flood events, while during the relatively warm period, both NAO and the force of the Asian Monsoon determine the precipitation of Hexi region.

关 键 词：文献记载 旱涝序列 树轮干湿 NAO 

分 类 号：P468.02[天文地球—大气科学及气象学]