基于文献计量分析的三峡库区消落带土壤 重金属污染特征研究

三峡库区消落带土壤/沉积物中重金属的研究受到日益重视,重金属的归趋对三峡库区的水环境和生态安全有重要意义。通过CNKI和WebofScience数据库检索了2001—2016年三峡消落带土壤/沉积物重金属污染特征研究的文献,并利用文献计量学方法分析文献特性及研究进展。2001—2016年,国内外发表的相关中英文文献分别为69篇、12篇,2011年发文量最多(15篇),此后一直维持在年产量≥5篇的水平,重庆和湖北的高校及研究所是研究主力。刊载论文最多的是环境学方面的期刊(19.75%)。所涉最多的主题是"重金属的污染调查及评价"(51.85%)。Cd的污染程度最大,且易迁移形态平均比例相对较高(38%),是消落带首要的污染控制元素,施肥是农业消落带Cd的主要来源。Pb和Hg的污染程度也较大且易迁移形态的比例均大于22%,交通污染是其主要来源。工业废物的点源排放对消落带重金属(Cd、Pb、Cu、Zn、As)普遍有较大贡献。消落带内重金属以垂向迁移为主,而植物对Cd、Cu、Zn具有较强的富集能力。淹水导致的pH、Eh、温度、有机质等变化对固液界面重金属的交互作用及形态变化有重要影响。今后,应加强消落带土壤理化性质和水力学性质变化对重金属地球化学行为影响,以及重金属示踪技术应用和泥沙富集重金属二次释放行为的研究。

Bibliometrical Analysis on Pollution Characteristics of Heavy Metals in Soil of Water Level Fluctuating Zone of Three Gorges Reservoir

Increasing attention has been paid to heavy metal study in soil/sediment of the water fluctuating zone (WLFZ) in the Three Gorges Reservoir (TGR). The fate of heavy metals is significantly important to the water and ecological safety in the TGR region. The status quo of heavy metal study in soil/sediment of WLFZ in the TGR from 2001 to 2016 was critically reviewed based on the bibliometrical analysis according to the current publications in the database of CNKI and Web of Science. To date, in total of 81 papers, including 69 papers in Chinese and 12 papers in English, were published globally. 2011 had the most publications (15 papers) and the annual amount thereafter stayed no less than 5. The universities and institutes of Chongqing Municipality and Hubei Province were the major contributors to these publications. 19.75% of the papers were published in the journals related to environmental science while the topic of investigation and evaluation of heavy metal pollution contained the most publications (51.85%). Cadmium (Cd) showed the highest degree of contamination with the proportion of the readily movable form exceeding 38%. Therefore, Cd is the primary element for heavy metal pollution control. Fertilization was the major source of Cd in the agricultural WLFZ. Lead (Pb) and Mercury (Hg) in soil/sediment of WLFZ also showed a high contamination degree with the proportion of the readily movable form exceeding 22%. Traffic wastes were the major source for these two heavy metals. In addition, the industrial wastes that were discharged as point sources in the TGR region generally contributed to the accumulation of heavy metals, e.g., Cd, Pb, Cu, Zn and As in the WLFZ. Heavy metals travelled mainly downward in the WLFZ while Cd, Cu and Zn were relatively easily absorbed by several plants in this area. The variations of pH, Eh, temperature and humic matter due to the impoundment of WLFZ exerted great effects on the interactions of heavy metals at soil/sediment-water interface. In the future, the influence of soil physiochemical and hydraulic property variations, the application of isotope tracing technology of typical heavy metals as well as the re-releasing characteristics of sediment associated heavy metals are suggested to be further considered in the WLFZ of TGR region.