WANG Yan1, HOU Guangliang1,2, JIN Sunmei1, GAO Jingyi1, DUAN Ronglei1,  LIU Jiaxin1

（1.School of Geogra phy Science, Qinghai Normal University, Xining 810008, China; 

2.Environmental Process Key Laboratory of Qinghai Province, Qinghai Normal University, Xining 810008, China）

Abstract：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. The 12.0-6.5 ka BP precipitation shows an increasing trend; the 6.5-4.0 ka BP precipitation fluctuation decreases; the 4.0-0.5 ka BP precipitation fluctuation range is relatively small, basically the same as modern times, and the change range does not exceed 100 mm In the extreme precipitation period, 12.3 ka BP has the least precipitation, which is 90 mm lower than the modern period; the maximum precipitation at 6.5 ka BP 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.

Key words：Sanjiangyuan area；Holocene；precipitation；Integrated reconstruction；Pollen

EARTH AND ENVIRONMENT Vol.51, No.2, Tot No.352, 2023, Page 173