Use of 210Pb and 137Cs to simultaneously constrain ages and sources of post-dam sediments in the Cordeaux reservoir, Sydney, Australia

Authors

Ava D. Simms, University of WollongongFollow
Colin D. Woodroffe, University of WollongongFollow
Brian G. Jones, University of WollongongFollow
H Heijnis, ANSTO
Rob Mann, Sydney Catchment Authority
J. Harrison, ANSTO

RIS ID

23836

Publication Details

Simms, A. D., Woodroffe, C. D., Jones, B. G., Heijnis, H., Mann, R. & Harrison, J. (2008). Use of 210Pb and 137Cs to simultaneously constrain ages and sources of post-dam sediments in the Cordeaux reservoir, Sydney, Australia. Journal of Environmental Radioactivity, 99, 1111-1120.

Abstract

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 ²¹⁰Pb_ex with depth and indicate slow accretion in the reservoir. The ratio of enrichment of radionuclides in sediment cores to ²¹⁰Pb_ex and ¹³⁷Cs 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.