三江源地区全新世降水序列集成重建  

Synthetically Reconstructed Precipitation Variability in the Sanjiangyuan from Holocene Pollen Records

作　　者：汪燕 侯光良 金孙梅[1] 高靖易 段荣蕾 刘佳欣 WANG Yan;HOU Guangliang;JIN Sunmei;GAO Jingyi;DUAN Ronglei;LIU Jiaxin(School of Geogra phy Science,Qinghai Normal University,Xining 810008,China;Environmental Process Key Laboratory of Qinghai Province,Qinghai Normal University,Xining 810008,China)

机构地区：[1]青海师范大学地理科学学院,西宁810008 [2]青海师范大学青海省自然地理与环境过程重点实验室,西宁810008

出　　处：《地球与环境》2023年第2期173-184,共12页Earth and Environment

基　　金：国家自然科学基金(42171165)。

摘　　要：三江源地区地处青藏高原腹地,是全球气候变化响应敏感区,重建该区全新世降水对理解过去气候变化具有重要意义。目前,三江源地区降水重建以单点为主,难以反映整个区域降水变化。本文通过利用下大武剖面化石孢粉记录,同时搜集该区6处化石孢粉点数据,运用转换函数法和点阵成面回归模型重建三江源地区全新世降水变化记录。结果显示:三江源地区全新世早中期降水高于现代年平均降水,全新世晚期降水开始下降。降水变化可分为3个阶段,12.0~6.5 ka B.P.降水波动增加;6.5~4.0 ka B.P.降水波动下降;4.0~0.5 ka B.P.降水波动幅度较小,与现代基本持平,变化幅度不超过100 mm;降水极端期为12.3 ka B.P.降水最少,较现代低90 mm左右;6.5 ka B.P.降水量达到最大值500 mm左右。本研究提供了三江源地区全新世降水变化记录,为研究三江源地区长尺度降水变化规律提供了参考依据。The Sanjiangyuan area is located in the hinterland of the Qinghai-Tibet Plateau and is a sensitive area in response to global climate change.The reconstruction of Holocene precipitation in this area is of great significance to the study of global change in the past.This study is based on the data of seven fossil pollen sites in the Sanjiangyuan area,the modern topsoil pollen data of the Qinghai-Tibet Plateau and the corresponding modern instrumental precipitation data.Based on the changes in precipitation records,the use of lattice surface regression model of fossil spore-pollen single-point precipitation records was used to fit the Holocene precipitation records of 7 pollen-sites to reconstruct the Holocene paleo-precipitation sequence in the Sanjiangyuan Sanjiangyuan area.The results showed that the early and mid Holocene precipitation in the Three Rivers Source area was higher than the modern annual average precipitation,and the precipitation in the late Holocene began to decline.The precipitation changes are clearly divided into three stages,namely,periods of 12.0-6.5 ka B.P.,6.5-4.0 ka B.P.,and 4.0-0.5 ka B.P.,respectively,corresponding to precipitation with an increasing trend,with an fluctuant decrease,and with a relatively small fluctuation range(less than100 mm)that basically compare to modern times,respectively.In the extreme precipitation period,12.3 ka B.P.has the least precipitation,which is 90 mm lower than the modern period;the maximum precipitation at 6.5 ka B.P.is about 500 mm.This article provides a record of the Holocene precipitation changes in the Sanjiangyuan area,and provides a reference for the study of long-scale precipitation changes in the Sanjiangyuan area.

关 键 词：三江源地区 全新世 降水 集成重建 孢粉 

分 类 号：P532[天文地球—古生物学与地层学]