Sedimentary records of extreme floods and channel geomorphological evolution in the Yangtze subaqueous delta
ID:1280 View Protection:PRIVATE Updated Time:2023-04-20 22:05:47 Hits:323 快闪报告

Start Time:2023-05-07 11:30(Asia/Shanghai)

Duration:5min

Session:1C 1C、第四纪地质与全球变化 » 1C-21C-2 第四纪地质与全球变化

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Abstract
Extreme flood and main stream swings have exerted significant influences on the sediment records of the Yangtze River delta. However, studies about the influence by the main stream swings to flood sediments remain limited. Based on chronological, sedimentological, and geochemical analysis of a sediment core CJK from outside of the south channel mouth in the Yangtze subaqueous delta, this work establishes the historical records of floods and main stream swings. The results show that the main stream swing periods mainly occurred in 1840-1860 CE (south channel), 1860-1890 CE (north channel), 1900-1927 CE (shift from north to the south channel), 1927-1940 CE (south channel), and 1940-1980 CE (north channel). 4 flood periods (1842-1852, 1922-1938, 1954-1962, and 1970-1983 CE) and 5 extreme floods (1860, 1870, 1890, 1945, and 1950 CE) were identified. Comparing the historical documents with above identified floods indicates that flood events are more easily identified when the main stream shift to the south channel, but not when the main stream shifted to the north channel (except high-magnitude and high-frequency floods). In addition, human activities (e.g. dam constructions) have significantly changed grain size compositions in the Yangtze subaqueous delta after 1980s, which possibly complicated the extraction of flood event signals.
Keywords
Extreme floods,Channel geomorphological evolution,Main stream swings,Sediment records,Anthropogenic impacts,Yangtze River delta
Speaker
李明宸
江苏师范大学

Submission Author
李明宸 江苏师范大学
周亮 江苏师范大学
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Important Date
  • Conference Date

    May 05

    2023

    to

    May 08

    2023

  • Mar 31 2023

    Draft paper submission deadline

  • May 25 2023

    Registration deadline

Sponsored By
青年地学论坛理事会
中国科学院青年创新促进会地学分会
Organized By
武汉大学
中国科学院精密测量科学与技术创新研究院
中国地质大学(武汉)
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