Insights into Shallow Freshwater Lakes Hydrology in the Yangtze Floodplain from Stable Water Isotope Tracers
Insights into Shallow Freshwater Lakes Hydrology in the Yangtze Floodplain from Stable Water Isotope Tracers
复制标题
利用水稳定同位素示踪研究长江滩区浅水湖泊水文
DOI：
10.3390/w14030506
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发表时间：
2022-02
期刊：
影响因子：
3.4
通讯作者：
Jing Li;Fan Song;Zhicheng Bao;Hongxiang Fan;Hua-wu Wu
中科院分区：
文献类型：
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作者：
Jing Li;Fan Song;Zhicheng Bao;Hongxiang Fan;Hua-wu Wu
通过耦合同位素示踪模型，湖水稳定同位素被广泛用于识别水文过程对未测量地貌的湖水平衡的相对重要性。2018年1月和5月，对长江中下游20个浅水淡水湖的同位素组成进行了研究。估算了特定于湖泊的输入水量(δI)和蒸发与流入的比值(E/I)，以探索跨MLY的特定湖泊水文。结果表明，与1月份相比，5月份有明显的同位素富集化趋势，这表明5月份蒸发量更大。不同湖泊的δ-18OI值在多年来表现出较大的变异性，这可能与流域面积、高程和降雨量等流域特征有关。长江中游湖泊的E/I比估计在1以下，表明长江中游湖泊以洪水为主，易受三峡大坝调度的影响。相比之下，长江三角洲(代码17-20)的湖泊E/I比值的变异性相对较小，因为这些拥有发达河网系统的湖泊通过人工调节进行了高度交换。我们对湖泊类型和相应的同位素演化模式的调查很可能是其他泛滥平原地貌的典型，它们的识别可以用来更好地预测对持续气候变化和大坝人为调节的水文响应。
Stable isotopes of lake waters are widely used to identify the relative importance of hydrological processes on the lake water balance across the ungauged landscape via the coupled-isotope tracer model. The isotopic compositions of twenty shallow freshwater lakes across the mid-lower reaches of Yangtze floodplain (MLY) were investigated in January and May of 2018. The lake-specific input water (δI) and evaporation-to-inflow (E/I) ratios were estimated to explore the specific lake hydrology across the MLY. Results showed that distinct isotopic enrichment trends in May compared with those in January, which was indicative of stronger evaporation in May. The δ18OI values of specific lakes exhibited large variability across the MLY, which may be related to the watershed properties, such as watershed area and elevation, and rainfall. The estimated E/I ratios of lakes across the MLY were below 1, which suggested that these lakes (code 1–15) are flood-dominated in the middle reaches of Yangtze River where lakes are susceptible to Three Gorges Dams regulations. By contrast, the relatively lower variability of lake E/I ratios were observed from the Yangtze River Delta (code 17–20) because these lakes with developed river network systems are highly exchanged by artificial regulation. Our investigation of lake types and corresponding isotopic evolution patterns are likely typical of other floodplain landscapes and their identification could be used to better predict hydrological responses to ongoing climate change and artificial regulations by dams.