秦安地区全新世气候的周期振荡特征  

Holocene Dry/Wet Fluctuations in Qin'an, West Loess Plateau

作　　者：S. Feng 夏敦胜[2] 汤懋苍[3] 陈发虎[2] 

机构地区：[1]Climate and Bio-Atmospheric Sciences Group,School of Natural Resources Sciences,University of Nebraska-Lincoln,Lincoln,NE 68583-0728,USA [2]中国科学院寒区旱区环境与工程研究所沙漠与沙漠化重点实验室 [3]中国科学院寒区旱区环境与工程研究所

出　　处：《冰川冻土》2006年第1期70-75,共6页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(40401064);科技部重点国际合作项目(2002CB714004);中国科学院寒区旱区环境与工程研究所知识创新工程项目(2003104)资助

摘　　要：通过对秦安大地湾8.3 m天然黄土剖面高分辨率(约为150 a)孢粉数据的研究,发现秦安地区孢粉数据与我国干旱、半干旱地区史料记载的旱涝演变有较为一致的变化,且有明显的冷干、暖湿的气候特征.奇异谱分析表明,秦安地区的旱涝变化有2 300 a、1 060 a、650 a和390 a的准振荡周期.准两千年周期与南亚季风的变化有密切的对应关系,也与太阳活动的强弱有关.A pollen-spore record of an 8. 2 m-long loess section from Qin＇an （35.76°N, 105.82°E） in western Loess Plateau, one of the origins of Chinese civilization, was studied. It provides insights into monsoonal Climate change in this semiarid region, a climatologically sensitive region. The variations of pollen-spore concentration in Qin＇an .are closely related to centennial dry/wet fluctuations in semiarid regions of China in the recent 2 000 years. The abrupt drop of pollen-spore concentration around 3 200 a BP is also consistent with millennium scale dryness and environmental deterioration around 1150-1300 a BC revealed by document records. A singular spectrum analysis suggests that the dry/wet fluctuations in Qin＇an have 2 300 a, 1060 a, 650 a and 390 a periods. The 2 300 a cycle is well correlated to the variations of South Asian monsoon during the Holocene. When South Asian monsoon is strong, the western Loess Plateau is wet, and vice versa. The 2 300 a period is also related to solar variability.

关 键 词：全新世 气候变化 奇异谱分析 秦安 

分 类 号：P534.632[天文地球—第四纪地质学]