HS9.4/GM7.14Quantifying sources and travel times of fine sediment in river basins: techniques, challenges and prospects (co-organized)
|Convener: Hugh Smith | Co-Conveners: Olivier Evrard , Philip Owens , Will Blake|
Sources of fine-grained sediment transported within river basins have been the focus of investigation for over two decades. During this time substantial progress has been made in establishing techniques for tracing the origin of fine sediment using various physical and chemical properties of soil and sediment. There has been some divergence in source tracing techniques with the growth of research in this area, while various methodological challenges remain to be further explored. More recently, there has been interest in quantifying the travel or residence time of fine sediment in river systems over contemporary timescales relevant to river basin management. To date, this has focused on using differences in radioactive decay rates of the fallout radionuclides Be-7, excess Pb-210 and Cs-137. Data on sediment travel times can provide a critical temporal dimension to fine sediment budgets based on source tracing, erosion and sediment yield measurements and/or modelling.
We invite contributions to this session that address any aspect of fine sediment source tracing or fingerprinting and approaches for quantifying sediment travel times as well as studies incorporating these techniques into catchment sediment budgets. Key themes that may be addressed include:
· Applications of source tracing or sediment fingerprinting techniques across a range of possible basin scales, land cover and hydro-climatic conditions.
· New methods for the statistical treatment of tracer data and applications of different un-mixing models
· Selection of tracer properties and identification of the physical or chemical basis for discrimination of sediment sources
· Identification of novel tracer properties for future application
· Potential for changes to source tracer properties during transport
· Approaches for dealing with uncertainty in estimates of proportional source contributions to downstream sediment
· Techniques for quantifying sediment travel times over timescales relevant to river basin management
· Integrated approaches to sediment budgeting: linking catchment source information with sediment travel times, erosion and sediment yield monitoring or modelling
· Assessment of temporal stability in sediment budget components using tracer-based information on sources and travel times