Acta Geographica Sinica ›› 2020, Vol. 75 ›› Issue (7): 1432-1450.doi: 10.11821/dlxb202007008

• Climate Change and Surface Process • Previous Articles     Next Articles

The assessment on hydroclimatic changes of different regions in China at multi-scale during the past millennium

ZHENG Jingyun1,2(), ZHANG Xuezhen1,2, LIU Yang1, HAO Zhixin1,2()   

  1. 1. Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, CAS, Beijing 100101, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2019-06-14 Revised:2020-06-03 Online:2020-07-25 Published:2020-09-25
  • Contact: HAO Zhixin E-mail:zhengjy@igsnrr.ac.cn;haozx@igsnrr.ac.cn
  • Supported by:
    National Key R&D Program of China(2017YFA0603300);National Natural Science Foundation of China(41831174);National Natural Science Foundation of China(41671036);Strategic Priority Research Program of the Chinese Academy of Sciences(XDA19040101);Key Research Programs of the Chinese Academy of Sciences(ZDRW-ZS-2017-4)

Abstract:

Based on the latest hydroclimatic reconstructions in peer-reviewed scientific journals, we summarize the multi-scale pattern on hydroclimatic changes and assess whether or not the variability of the 20th century is unusual in the context of the past millennium for different regions of China. The main conclusions are as follows: (1) In the central-eastern China, the dry/wet series reconstructed from historical documents after 1400 have high confidence level, while before 1400, the reconstructions only in half of the period have high confidence due to the shortage of records. In northeastern China and eastern Inner Mongolia, centennial-scale reconstructions from lake sediments at multiple sites are in low agreement in most of periods. In Loess Plateau, Hexi Corridor, central to northern Xinjiang, northeastern and southeastern Tibetan Plateau, hydroclimatic reconstructions from tree rings have robust agreement within the same region. (2) All sub-regions of China show significant cycles with 90% confidence level at inter-annual, inter-decadal and centennial scales. The cycles of 2.5 a, 60-80 a and 110-120 a are detected over all the regions, while the cycles of 3.5-5.0 a and 20-35 a mainly occur in the Loess Plateau, Tibetan Plateau, northeastern and central-eastern China. The cycle of quasi-45 a only occurs in northeastern and central-eastern China. Moreover, the hydroclimatic changes are out of phase in different regions. (3) The 20th century is one of the wettest centuries in the past 3000 years in northeastern Tibetan Plateau. However, most series from other regions show that the inter-decadal hydroclimatic variability of the 20th century does not exceed the amplitude of natural variability, which had ever occurred during the past millennium.

Key words: multi-scale pattern, hydroclimatic changes, place of hydroclimatic variability for the 20th century in history, past millennium, China