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D.E.Walling 作题为《利用河流示踪泥沙的运动和
迁移辅助流域管理》的主题报告
Des E. WALLING: USING ENVIRONMENTAL RADIONUCLIDES TO TRACE SEDIMENT MOBILISATION AND DELIVERY IN RIVER BASINS AS AN AID TO CATCHMENT MANAGEMENT
Abstract: Although sediment problems have long been
recognised in those areas of the world with high rates of soil loss and
high specific sediment yields, recent years have seen a growing
recognition of the wider significance of fine sediment as an
environmental problem. This has resulted in a growing need to
incorporate sediment control strategies into catchment management
programmes. The design of effective sediment control strategies is,
however, heavily dependent upon a sound understanding and knowledge of
sediment mobilisation and delivery within the catchment system and thus
the overall sediment budget. Traditional monitoring techniques are
generally unable to provide information on the internal functioning of
the sediment budget. Against this background, there is a need for new
approaches to data collection and tracing techniques are being
increasingly used. Environmental radionuclides provide a particularly
useful tool for tracing sediment mobilisation and delivery and this
paper provides further information on the basis for their use and on
their potential applications. Selected examples of their application to
documenting rates of soil loss and sediment delivery from cultivated
fields, sediment source tracing, and documenting rates of floodplain
sedimentation and longer-term changes in suspended sediment properties
are provided.