Acta Geographica Sinica ›› 2021, Vol. 76 ›› Issue (5): 1065-1077.doi: 10.11821/dlxb202105002

• Research on the Arctic Region • Previous Articles     Next Articles

Characteristic analysis of organic carbon output and its affecting factors of Arctic rivers in Siberia

LIU Shiqi1(), WANG Ping1,2(), WANG Tianye3, HUANG Qiwei1,2, YU Jingjie1,2   

  1. 1. Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
    3. School of Water Conservancy Engineering, Zhengzhou University, Zhengzhou 450001, China
  • Received:2020-03-05 Revised:2020-12-02 Online:2021-05-25 Published:2021-07-25
  • Contact: WANG Ping E-mail:liusq@igsnrr.ac.cn;wangping@igsnrr.ac.cn
  • Supported by:
    National Natural Science Foundation of China(E1C10060AE);The Science and Technology Basic Resources Investigation Program of China(2017FY101301);The Science and Technology Basic Resources Investigation Program of China(2017FY101302);Chinese Academy of Sciences(ZDRW-ZS-2017-4);China Postdoctoral Science Foundation(O7Z76095Z1)

Abstract:

As an important component of Arctic carbon cycle, riverine organic carbon export is very sensitive to climate change. In order to analyze the organic carbon output from 2004 to 2017 of Ob, Yenisei and Lena rivers in Siberia of Russia, river discharge and organic carbon data from the ArcticGRO (https://arcticgreatrivers.org/) were used in this study through mathematical statistical analysis and other methods. Results showed that the total annual organic carbon output of these three rivers is about 23 Tg, among which the dissolved organic carbon (DOC) output is approximately 18.55 Tg, more than half of the total in Arctic regions, and nearly 4 times of particulate organic carbon (POC) output. The output of annual DOC from 2009 to 2017 is significantly different from that of 1999-2008, DOC output of Ob River increased by 18% annually, Lena River increased by almost 70%, while Yenisei River dropped by 13%. The organic carbon output in spring and summer reached more than 85% of the whole year, with an output peak in spring, but the outputs of Ob River in spring and summer were almost the same. The organic carbon output characteristics of these river basins are different in seasonality, which was mainly affected by runoff, permafrost and human activities. Among them, the total DOC output has a significant positive correlation with runoff variation in terms of inter-annual and seasonal changes. In general, DOC concentration becomes larger as the discharge increases. Permafrost also has notable influence on river DOC and POC due to various types of distribution. Therefore, the study of the characteristics and influencing factors of the organic carbon output of Arctic rivers under climate change is conducive to in-depth understanding of the comprehensive response of the organic carbon output of Arctic rivers to climate and environmental changes, which lays a foundation for revealing the process of the Arctic carbon cycle under climate change.

Key words: Arctic river, Siberia, organic carbon, runoff, permafrost