Using Pu-239 as a tracer for fine sediment sources in the Daly River, Northern Australia

R Lal, Keith Fifield, Stephen Tims, Robert Wasson, David Howe

    Research output: Chapter in Book/Report/Conference proceedingConference Paper published in Proceedingspeer-review

    Abstract

    The Daly River drains a large (52500 km2) and mainly undisturbed catchment in the Australian wet–dry tropics. Clearing and cropping since 2002 have raised concerns about possible increased sediment input into the river and motivated this study of its fine sediment sources. Using 239Pu as a tracer it is shown that the fine sediments originate mainly from erosion by gullying and channel change. Although the results also indicate that the surface soil contribution to the river channel sediments from sheet erosion has increased to 5-22% for the Daly River and 7-28% for the Douglas River (a tributary of the Daly River) in 2009 vs. 3-6% for the Daly River and 4-9% for the Douglas River in 2005. This excess top soil likely originates from thecleared land adjacent to the Daly River since 2005. However, channel widening largely as a result of hydrologic change is still the dominant sediment source in this catchment.
    Original languageEnglish
    Title of host publicationHeavy Ion Accelerator Symposium 2014
    Place of PublicationFrance
    PublisherEDP Sciences
    Pages1-7
    Number of pages7
    Volume91
    DOIs
    Publication statusPublished - 2015
    EventHeavy Ion Accelerator Symposium on Fundamental and Applied Science - 2014 - Canberra
    Duration: 30 Jun 20142 Jul 2014

    Conference

    ConferenceHeavy Ion Accelerator Symposium on Fundamental and Applied Science - 2014
    Period30/06/142/07/14

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