PROGRESS IN GEOGRAPHY ›› 2017, Vol. 36 ›› Issue (11): 1413-1422.doi: 10.18306/dlkxjz.2017.11.010

• Orginal Article • Previous Articles     Next Articles

A 240-year sedimentary record of paleoflood events from the Huangmaotan Lake, northern Jiangxi Province

Shuang WU1(), Qian LIU1, Xiangming CAO1, Zhongping LAI2, Yuanhui CHEN1, Yulian JIA1,3,*()   

  1. 1. School of Geography and Environment, Jiangxi Normal University, Nanchang 330022, China
    2. School of Earth Sciences, China University of Geosciences, Wuhan 430074, China
    3. Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Nanchang 330022, China
  • Online:2017-12-07 Published:2017-12-07
  • Contact: Yulian JIA;
  • Supported by:
    The Collaborative Innovation Center for Major Ecological Security Issues of Jiangxi Province and Monitoring Implementation, No.JXS-EW-00;Open Foundation of Ministry of Education Key Laboratory of Poyang Lake Wetland and Watershed Research (Jiangxi Normal University), No.ZK2013003


Paleoflood reconstruction is one of the foci of global change research and in the last decades, increasingly more attention has been paid to investigate lacustrine sediments to identify sedimentary proxies (such as chemical, physical) and extract environmental information of flood events. This article attempts to elucidate the issue based on recent Huangmaotan lacustrine sediments and reconstructs the regional paleoflood records of northern Jiangxi since the Little Ice Age. This investigation, using the 137Cs and 210Pb-based chronology, first presents a comparative analysis of grain size parameters, geochemical indices of sediments, and annual number of days with rainfall >50 mm during the last 60 years. It indicates that the particle size parameters, including (coarse silt+sand)/clay ratios, mean grain size (um), and ratios of Zr/Rb, Zr/Fe, and Ti/Rb correlated well with 11 of the 13 flood events recorded in historical documents during 1950-2010, which suggests that these indices can be applied to identify flood events from lacustrine sediments. Based on these indices, 23 of the 31 flood events during 1769-1950 recorded in historical documents are identified. The study indicates that: (1) Zr/Rb, Zr/Fe, and Ti/Rb ratios, (coarse silt + sand)/clay ratio, and mean grain size are sensitive to flood-event deposits, especially Zr/Rb ratios. Strong catchment erosion during flooding periods and intensified river discharge, we argue, are favorable conditions for the delivery of more coarse particles to the lake to deposit. This type of horizons, with high Zr and Ti, and low Fe and Rb, contrast with background lacustrine sediments. (2) This study also demonstrates that there were more floods occurred during the recent warm period (1900-2010) compared with the last cold stage of the Little Ice Age (1800-1900). (3) On multi-decadal time scales, regional floods were high-frequency incidence in the 1820s-1840s and the 1860s-1870s, when the East-Asian summer monsoon was stronger and rainfall was above normal in the middle and lower reaches of the Yangtze River catchment, and in two warm phases (the 1920s-1940s and the 1980s-1990s), consistent with the characteristics of heavy floods in the middle and lower reaches of the Yangtze River during the 20th century. The study provides a scientific basis for reconstructing paleoflood change by lacustrine sediments, and extends the time series of flood events by lake sediments.

Key words: lacustrine sediments, flood proxy, grain size, Zr/Rb, Huangmaotan Lake