摘要
Cd属于积蓄性有毒元素,引起慢性中毒的潜伏期可达10～30年之久.中国正在进行的多目标地球化学调查成果显示,长江流域存在全流域的Cd异常.对长江上、中、下游冲洪积物中Cd质量分数的初步研究,发现长江流域Cd异常以自然风化作用为主.针对长江流域Cd异常的特点,在统一技术规范的基础上,采用枯、丰水期悬浮物测量技术、河漫滩/泛滥平原沉积物沉积柱分层采样技术,同位素测年技术来建立长江各支流Cd输入通量的时空变化模型和定量评估方法,估算长江各支流的Cd输入通量,使分散于沿江各省的区域地球化学评价置于同一平台,从而为全面研究长江流域Cd异常的形成机理创造条件.
Cadmium is an cumulative toxic element, which could result in chronic poisoning with an incubation period of as long as 10~30 years. The results of the currently implemented multi-purpose geochemical survey show that there are Cd anomalies spreading along the whole Yangtze River Basin. A preliminary study of the contents of Cd in alluvium on upper, middle and lower reaches of the Yangtze River reveals that these Cd anomalies are mainly caused by natural weathering. On the basis of a unified technical regulation and aiming at the features of the Cd anomalies, we proposed a spatial and temporal variation model for the quantitative assessment of the Cd input flux from tributaries.The model is established by applying the suspended particle matter survey during low-and high-water periods, the stratification sampling of sedimentation column on overbank sediments/floodplain sediments, and the isotopic dating. Thus, the Cd input flux from tributaries could be calculated under a unified regulation and the regional geochemical assessments for the provinces along the Yangtze River could be made under a unified standard, This should create the conditions for a comprehensive study of the mechanics of the Cd anomalies along the Yangtze River.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2005年第1期261-272,共12页
Earth Science Frontiers
基金
国家重点基础研究发展规划项目(G1999045707)
国土资源大调查项目(200420130002
200414200011)
科学技术部社会公益项目(2001DIA10021)
关键词
Cd异常源追踪
输入通量
定量评价
研究框架
长江流域
source tracking of Cd anomaly
input flux
quantitative assessment
research framework
Yangtze River Basin
