IMIXSED project

Siltation presents a credible threat to river basin ecosystem service provision and water security. River silt originates, however, on catchment hillslopes and the primary driver for mobilisation and translocation downstream is soil erosion on agricultural land where loss of this finite resource threatens food security. Knowledge of sediment source and transfer dynamics in river catchments is critical to inform management policy decisions to maintain and enhance future food and water security.

Identification of the source and behaviour of different types of sediment is critical if we are to design effective management plans. Cutting edge nuclear techniques have been developed to trace river silt back to source, in a jointly Coordinated Research Programme between the UN Food and Agriculture Organisation and the International Atomic Energy Agency. However, these new techniques have led to a step change in data complexity. While these datasets capture real world complexity in time and space, the conventional statistical approaches to quantify sediment provenance do not. This severely limits the power of the new tracing techniques.

Advances in ecological source models based on Bayesian statistics, however, offer a solution. New models e.g. MixSIAR have been developed that can deal with the complexity in a quantitative way and, if tailored to specific river basin sediment data, could help us address the above challenge.

The central goal of the IMIXSED Project (Integrating isotopic techniques with Bayesian modelling for improved assessment and management of global sedimentation problems) is therefore to marry together the strengths of isotopic sediment tracer technology in the EU, with ecological source apportionment models developed by US scientists, to deliver a powerful tool to combat threats to global food and water security.

The tool will be showcased through its application in Tanzanian lake catchments and Ethiopian water-supply catchments where diffuse sediment and nutrient pollution from agriculture currently threatens food, water and, through siltation of HEP dams, energy security.

The Research and Innovation Staff Exchange (RISE) programme proposed here is international in two directions linked to the two objectives mentioned. In the first objective, the project will bring new modelling technology developed by US scientists to the EU, to be embedded in the practice of EU sediment tracing specialists; this is termed the IMIXSED approach. The other direction the programme will work is to train developing nations’ scientists (second objective) in the use of IMIXSED technology, through secondment to EU sediment tracing centres of excellence. This activity will help build global capacity in sediment tracing tools and will show how the IMIXSED approach can be used to combat food, water and energy security in demonstration catchments where agriculture is leading to siltation of reservoirs.

For more information and to discuss scientific issues, please contact Professor Will Blake:

Professor Will Blake
School of Geography, Earth and Environmental Sciences
Drake Circus
Plymouth
PL4 8AA

For more information regarding project co-ordination and administration, please contact Dr Claire Kelly:

Dr Claire Kelly
School of Geography, Earth and Environmental Sciences
Drake Circus
Plymouth
PL4 8AA