Simms Ava D, Woodroffe Colin, Jones Brian G, Heijnis Henk, Mann Rob A, Harrison Jennifer
GeoQuEST Research Centre, School of Earth and Environmental Sciences, University of Wollongong, Northfields Avenue, Gwynneville, NSW 2522, Australia.
J Environ Radioact. 2008 Jul;99(7):1111-20. doi: 10.1016/j.jenvrad.2008.01.002. Epub 2008 Mar 4.
Environmental radionuclides can be employed as tracers of sediment movement and delivery to water bodies such as lakes and reservoirs. The chronologies of sediments that have accumulated in the Cordeaux reservoir in Sydney, Australia, were determined by the rate of change of (210)Pb(ex) with depth and indicate slow accretion in the reservoir. The ratio of enrichment of radionuclides in sediment cores to (210)Pb(ex) and (137)Cs concentrations in a reference soil sample within the Cordeaux catchment indicates that the dominant source of sediment in the Cordeaux reservoir is surface erosion (detachment and removal of sediment at depths less than 30 cm). However, in the Kembla Creek arm of the reservoir a mixture of sources was detected and includes sheet and rill erosion together with sub-soil contributions. Implications for the utility of these radionuclide sedimentation assessments, especially where samples are limited, are that well-constrained chronologies and sources of soil erosion are facilitated.
环境放射性核素可作为沉积物运动和输送至湖泊及水库等水体的示踪剂。澳大利亚悉尼科尔多水库中积累的沉积物年代，是通过（210）Pb（ex）随深度的变化率确定的，表明该水库的淤积速度较慢。科尔多集水区内沉积物芯中放射性核素的富集率与参考土壤样品中（210）Pb（ex）和（137）Cs浓度的比值表明，科尔多水库沉积物的主要来源是地表侵蚀（深度小于30厘米处沉积物的剥离和去除）。然而，在水库的肯布拉溪支流中，检测到了多种来源的混合，包括片蚀和细沟侵蚀以及下层土壤的贡献。这些放射性核素沉积评估的实用性，特别是在样本有限的情况下，意味着有助于确定受严格约束的年代和土壤侵蚀来源。
