With the aim of revealing the potential ecological risk and distribution characteristics of heavy metals on the surface sediment at the Shawan River section of Yelang Lake, the following three analyses were first performed: (1) analysis of grain-size composition on sediment samples collected at seven different sites in the water-level-fluctuation zone (WLFZ); (2) analysis of bulk sediment content of six heavy metals, namely, Cd, Cr, Pb, Mn, Zn, and Cu; and (3) the correlation analysis of grain-size composition and heavy metal content in the sediment. Afterwards, the approach of Hakanson potential ecological risk index was employed to analyze the risk of heavy metal pollution in sediments of seven WLFZ plots. The outcomes indicate that (1) the mean sediment grain size at each sampling site was generally >0.063 mm, with gravel grains (>1 mm) and sand grains (0.22–1 mm) accounting for the largest proportions; (2) the site-averaged mean sediment content of each of the six heavy metals was significantly higher than their respective geochemical background contents in the sediment of Guizhou Province, and the grain-size dependence of the bulk sediment content of heavy metals was not significant; (3) the distribution of Cr was relatively independent of other metals, which was in contrast to notable positive correlations observed between other metals; and (4) in accordance with the approach of Hakanson potential ecological risk index, for these heavy metals, their potential ecological risk reduced by the order of Zn < Cr < Cu < Pb < Cd, with Cd having a mean potential risk index (E_i) of 566.13, suggestive of a very high level of potential ecological risk, Zn, Cr, and Cu having a mild potential ecological risk, and Pb having moderate potential ecological risk. Cd largely contributes to the comprehensive ecological risk index RI is the largest, thereby having important environmental implications.

中文翻译：

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夜浪湖沙湾河段水位波动带沉积物重金属分布及生态风险

为揭示夜郎湖沙湾河段表层沉积物中重金属的潜在生态风险及分布特征，首先进行了以下三项分析：(1) 采集的沉积物样品粒度组成分析水位波动带（WLFZ）的七个不同地点；(2) Cd、Cr、Pb、Mn、Zn、Cu 6种重金属大块沉积物含量分析；(3)沉积物中粒度组成与重金属含量的相关性分析。随后，采用Hakanson潜在生态风险指数法对7个WLFZ样地沉积物重金属污染风险进行分析。结果表明：（1）各采样点沉积物平均粒径一般>0.063 mm，砾石粒（> 1 毫米）和砂粒（0.22-1 毫米）占最大比例；(2)贵州省沉积物中6种重金属的场地平均含沙量均显着高于其各自的地球化学背景含量，重金属总体含沙量的粒度依赖性不显着; (3) Cr 的分布相对独立于其他金属，这与观察到的其他金属之间显着的正相关相反；(4) 根据Hakanson潜在生态风险指数的方法，对于这些重金属，其潜在生态风险按Zn < Cr < Cu < Pb < Cd的顺序降低，其中Cd具有平均潜在风险指数（(2)贵州省沉积物中6种重金属的场地平均含沙量均显着高于其各自的地球化学背景含量，重金属总体含沙量的粒度依赖性不显着; (3) Cr 的分布相对独立于其他金属，这与观察到的其他金属之间显着的正相关相反；(4) 根据Hakanson潜在生态风险指数的方法，对于这些重金属，其潜在生态风险按Zn < Cr < Cu < Pb < Cd的顺序降低，其中Cd具有平均潜在风险指数（(2)贵州省沉积物中6种重金属的场地平均含沙量均显着高于其各自的地球化学背景含量，重金属总体含沙量的粒度依赖性不显着; (3) Cr 的分布相对独立于其他金属，这与观察到的其他金属之间显着的正相关相反；(4) 根据Hakanson潜在生态风险指数的方法，对于这些重金属，其潜在生态风险按Zn < Cr < Cu < Pb < Cd的顺序降低，其中Cd具有平均潜在风险指数（重金属散装沉积物含量的粒度依赖性不显着；(3) Cr 的分布相对独立于其他金属，这与观察到的其他金属之间显着的正相关相反；(4) 根据Hakanson潜在生态风险指数的方法，对于这些重金属，其潜在生态风险按Zn < Cr < Cu < Pb < Cd的顺序降低，其中Cd具有平均潜在风险指数（重金属散装沉积物含量的粒度依赖性不显着；(3) Cr 的分布相对独立于其他金属，这与观察到的其他金属之间显着的正相关相反；(4) 根据Hakanson潜在生态风险指数的方法，对于这些重金属，其潜在生态风险按Zn < Cr < Cu < Pb < Cd的顺序降低，其中Cd具有平均潜在风险指数（E _i ) 为 566.13，表明潜在生态风险非常高，Zn、Cr ​​和 Cu 具有轻度潜在生态风险，Pb 具有中等潜在生态风险。Cd 对综合生态风险指数 RI 的贡献最大，因此具有重要的环境影响。