The Lake Tian E Zhou (TEZ, an oxbow lake) was formed during the rerouting of the Changjiang River in 1972, with strong influences from the main river channel and flood events. Herein, a sediment core was collected from the Lake TEZ for the measurements of carbon isotopes and biomarkers, including stable carbon isotopes (δ¹³C), radiocarbon composition (Δ¹⁴C), and lignin phenols, as well as lead-210 to reconstruct recent heavy flood events over the past 70 years. At the 24–26 cm interval, the sediment contained the highest OC%, TN%, and lignin phenols content, as well as significantly depleted ¹³C but enriched ¹⁴C, corresponding to the extreme flood event in 1998. In addition, statistics from t-test showed that lignin phenols normalized to OC (Λ8), the concentration of 3, 5-dihydroxy benzoic acid (3, 5-BD), and the ratio of p-hydroxy benzophenone to total hydroxyl phenols (PHB/HP) were all significantly different between the layers containing flood deposits and the layers deposited under normal non-flood conditions (p<0.05). These results indicate that the later three parameters are highly related to flood events and can be used as compelling proxies, along with sediment chronology, for hydrological changes and storm/flood events in the river basin and coastal marine environments.

中文翻译：

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碳同位素和木质素酚用于追踪长江中游过去70年的洪水

1972年长江改道期间形成了天峨洲湖（TEZ，牛弓湖），受到主要河道和洪水事件的强烈影响。在此，沉淀物芯从湖TEZ收集碳同位素和生物标志物，包括稳定的碳同位素（的测量δ ¹³ C），放射性碳组合物（Δ ¹⁴ C），和木质素酚，以及引线210来重建最近70年来最近的特大洪水事件。在24–26 cm的间隔内，沉积物中的OC％，TN％和木质素酚含量最高，并且¹³ C明显耗竭，但¹⁴ C富集C，对应于1998年的特大洪水事件。此外，t检验的统计数据表明，木质素酚标准化为OC（Λ8），3，5-二羟基苯甲酸（3，5-BD）的浓度和在含洪沉积物的层和在正常非洪泛条件下沉积的层之间，对羟基二苯甲酮与总羟基酚的比率（PHB / HP）均存在显着差异（p <0.05）。这些结果表明，后三个参数与洪水事件高度相关，可以作为引人注目的代理人，以及沉积物年代学，用于流域和沿海海洋环境中的水文变化和暴雨/洪水事件。