State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, 430072, China.
Hubei Key Laboratory of Water System Science for Sponge City Construction, Wuhan University, Wuhan, 430072, China.
Environ Sci Pollut Res Int. 2021 Aug;28(29):39186-39198. doi: 10.1007/s11356-021-13484-7. Epub 2021 Mar 22.
Urbanization and human activities have significantly modified the geochemical signatures of urban streams worldwide. However, the geochemical characteristics of urban streams in Wuhan, one of the core cities in the Yangtze River Economic Belt in China, remain largely unstudied. Here, we examined the stable isotopes and geochemistry of urban streams at 73 locations in the central districts in Wuhan during May 2019. Maps of isotopic signatures reflected a non-free-flowing state in part of the urban stream system in Wuhan. A lower DO and a higher EC level were found in urban streams relative to the adjacent Yangtze River. The Na, K, and Cl concentrations in urban streams were > 3.0 times as high as those in the Yangtze River, and there was a slight increasing trend between 1.1 and 1.4 times for other major ions. The mildly elevated Fe concentration (1.3 times) and markedly elevated Mn concentration (> 5.0 times) were observed in urban streams. Spearman's correlation analysis indicated strong positive bivariate correlations among Na, K, and Cl in urban streams, and an urban geochemical principal component was identified by principal component analysis. Plotting Na/(Na + Ca) versus total dissolved solids (TDS) indicated a potential risk of "urban stream syndrome." These findings can enhance the knowledge of anthropogenic impacts on current urban stream water quality and provide reference for the restoration and improvement of water ecology functions of the urban stream system in Wuhan.
城市化和人类活动显著改变了全球城市溪流的地球化学特征。然而，中国长江经济带核心城市之一武汉的城市溪流的地球化学特征在很大程度上仍未得到研究。在这里，我们于 2019 年 5 月在武汉中心区的 73 个地点检查了城市溪流的稳定同位素和地球化学特征。同位素特征图反映了武汉部分城市溪流系统处于非自由流动状态。与相邻的长江相比，城市溪流中的 DO 和 EC 水平较低。城市溪流中的 Na、K 和 Cl 浓度比长江高>3.0 倍，其他主要离子的浓度呈 1.1 至 1.4 倍的轻微上升趋势。城市溪流中的 Fe 浓度（1.3 倍）略有升高，Mn 浓度（>5.0 倍）明显升高。Spearman 相关分析表明，城市溪流中 Na、K 和 Cl 之间存在强烈的正二变量相关性，通过主成分分析确定了一个城市地球化学主成分。绘制 Na/(Na + Ca)与总溶解固体（TDS）的关系图表明存在“城市溪流综合征”的潜在风险。这些发现可以提高对当前城市溪流水质的人为影响的认识，并为武汉城市溪流系统的恢复和改善水生态功能提供参考。
