Jiang Xiaoliang, Xiong Ziqian, Liu Hui, Liu Guihua, Liu Wenzhi
Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, People's Republic of China.
Key Laboratory of Ecological Impacts of Hydraulic-Projects and Restoration of Aquatic Ecosystem of Ministry of Water Resources, Institute of Hydroecology, Ministry of Water Resources and Chinese Academy of Sciences, Wuhan, 430079, People's Republic of China.
Environ Sci Pollut Res Int. 2017 Jan;24(1):436-444. doi: 10.1007/s11356-016-7775-x. Epub 2016 Oct 10.
The majority of rivers in the world have been dammed, and over 45,000 large reservoirs have been constructed for multiple purposes. Riparian and reservoir shorelines are the two most important wetland types in a dammed river. To date, few studies have concerned the heavy metal pollution in wetland soils of these river-reservoir systems. In this study, we measured the concentrations of ten heavy metals (Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sr, and Zn) in surface soils collected from riparian and reservoir shorelines along the Han River in different seasons. Our results found that the Co, Cu, and Ni concentrations in riparian wetlands were significantly lower than those in reservoir shorelines. In riparian wetlands, only soil Sr concentration significantly increased after summer and autumn submergence. Multivariate statistical analyses demonstrated that Ba and Cd might originate from industrial and mining sources, whereas Sr and Mn predominantly originated from natural rock weathering. The ecological risk assessment analysis indicated that both riparian and reservoir shorelines along the Han River in China exhibited a moderate ecological risk in soil heavy metals. The upper Han River basin is the water resource area of China's Middle Route of the South-to-North Water Transfer Project. Therefore, to control the contamination of heavy metals in wetland soils, more efforts should be focused on reducing the discharge of mining and industrial pollutants into the riparian and reservoir shorelines.
世界上大多数河流都已筑坝，并且已建造了45000多个用于多种目的的大型水库。河岸带和水库岸线是筑坝河流中最重要的两种湿地类型。迄今为止，很少有研究关注这些河流-水库系统湿地土壤中的重金属污染。在本研究中，我们测量了不同季节从汉江沿岸的河岸带和水库岸线采集的表层土壤中十种重金属（钡、镉、钴、铬、铜、锰、镍、铅、锶和锌）的浓度。我们的结果发现，河岸带湿地中的钴、铜和镍浓度显著低于水库岸线中的浓度。在河岸带湿地中，仅土壤锶浓度在夏秋淹没后显著增加。多变量统计分析表明，钡和镉可能源自工业和采矿源，而锶和锰主要源自天然岩石风化。生态风险评估分析表明，中国汉江沿岸的河岸带和水库岸线在土壤重金属方面均呈现中度生态风险。汉江上游流域是中国南水北调中线工程的水源区。因此，为了控制湿地土壤中的重金属污染，应更加努力减少采矿和工业污染物向河岸带和水库岸线的排放。
