树轮记录的西北季风边缘区干旱变化

发布时间：2018-03-17 22:29

本文选题：树轮年表　切入点：PDSI　出处：《冰川冻土》2017年02期 　论文类型：期刊论文

【摘要】：祁连山东部位于亚洲季风西北边缘区,对气候变化十分敏感。由于该区位于半干旱区,降水的变化直接影响人类社会经济的发展,所以研究该区干旱变化情况及其机制非常重要。利用采自祁连山东部西北季风边缘、地处半干旱区的吐鲁沟地区的油松树轮样芯,建立了树轮宽度年表,时间跨度为1866-2003AD。树轮宽度年表与气象因子相关分析结果显示树木生长主要响应生长季内的降水和干旱变化。该年表与附近区域利用树轮宽度重建的帕尔默干旱指数(PDSI)进行对比,结果显示严重的干旱时间发生在1920s-1930s、1966年、1974年、1982年和1990s和21世纪初。多窗谱分析研究表明,该区年表序列存在显著的2~4 a周期(P0.05),该周期与ENSO变率吻合,与在贺兰山、祁连山其他地区、兴隆山及贵清山研究结果一致,表明这些区域可能受共同气候因子的影响。
[Abstract]:The eastern Qilian Mountains is located in the northwestern margin of the Asian monsoon and is very sensitive to climate change. As the region is located in the semi-arid region, the change of precipitation directly affects the development of human society and economy. Therefore, it is very important to study the drought variation and its mechanism in this area. Using the sample cores of Pinus tabulaeformis collected from the northwest monsoon edge of the eastern Qilian Mountains and located in the Turugou region in the semi-arid region, a tree ring width chronology has been established. The time span is 1866-2003.The results of correlation analysis between tree ring width and meteorological factors show that tree growth mainly responds to precipitation and drought changes in growing season. This chronology is compared with the Palmer drought index (PDSI), which is reconstructed by tree ring width in nearby area. The results show that the severe drought time occurred in 1920s-1930s, 1966, 1974, 1982, 1990s and 1982. The results of multi-window spectral analysis show that there is a significant 2-year period of P0.05A in the chronological table sequence in this area, which coincides with the rate of ENSO variability and is similar to that in Helan Mountain. The results of the studies in other areas of Qilian Mountains, Xinglong Mountain and Guiqing Mountains are consistent, indicating that these regions may be affected by common climatic factors.
【作者单位】：兰州大学资源环境学院西部环境教育部重点实验室;
【基金】：国家自然科学基金项目(41401047) 兰州大学中央高校基本科研业务费专项项目(lzujbky-2016-163)资助
【分类号】：P532

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