TRACING 2024
Emerging strategies of sediment and contaminant tracing in catchments and river systems
The School took place from 3 to 7 March 2024
Meeting place: Centre Port-Royal, Saint-Lambert-des-Bois,
Ile-de-France/Paris Region, France
Main organizer: Olivier Evrard, Laboratoire des Sciences du Climat et de l’Environnement (LSCE)
Other organizers: Sébastien Bertrand (GEOPS), Charlotte Skonieczny (GEOPS), Arnaud Huguet (METIS), Sabine Kraushaar (UniWien)
With the financial support of the following institutions
This event was supported by the IPSL – Climate Graduate School which is funded by the French National Research Agency – ANR (ANR-11-IDEX-0004 – 17-EURE-0006). It is also received funding dedicated to training schools from the European Geosciences Union (EGU), the Geoscience, Climate, Environment, Planets Graduate School from University Paris-Saclay, the CNRS Fédération Île-de-France de Recherche en Environnement (FIRE) and the French Geochemistry Experimental Network (RéGEF).
Background: outputs of the first TRACING School organised in 2021
A publication describing the main outputs of the discussions held during the TRACING School has been accepted in the Journal of Soils and Sediments in March 2022.
Evrard, O., et al. (2022). Improving the design and implementation of sediment fingerprinting studies: Summary and outcomes of the TRACING 2021 Scientific School. Journal of Soils and Sediments.
The final version of the publication is now accessible on the journal website:
https://link.springer.com/article/10.1007/s11368-022-03203-1
Popularization article about the Tracing School is available here (in French)
Description of the School
Context and objectives of the School
Soil and water resources that are essential to human and aquatic life are increasingly threatened by human activities and the impacts of land use and climate change. Sediment and sediment-associated constituents, in particular, can contribute substantially to water-quality impairment. In order to take effective conservation measures to protect these resources from erosion and alteration, and use them in a more sustainable way, a preliminary assessment is needed to: (1) quantify soil losses; (2) identify the sources and the pathways of runoff and sediment across the landscapes to the river systems; and (3) calculate the transfer and residence times of sediment and particle-bound contaminants in the river network.
Several innovative techniques have been developed recently opening up new avenues to establish this assessment of sediment flux in the critical zone. These innovative techniques include the tracing or “fingerprinting” methods to identify the sources and quantify the dynamics of sediment and particle-bound contaminants, high resolution topographic mapping using various emerging technologies (i.e Lidar) to map connectivity and sediment pathways, the development and installation of multiple low-cost sensors in the rivers. However, the use of these techniques is often associated with several methodological and statistical limitations, that are often reported although rarely addressed in the framework of concerted actions taken at the level of the international scientific community. Among the main methodological difficulties associated with these techniques are the following:
- conservativeness of tracers during the erosion to delivery cycle;
- collection and representativeness of sampling in the field;
- use of correction factors to remove the effect associated with differences in particle size or organic matter content between source and target samples;
- Bayesian versus multivariate statistical analyses;
- calibration of sensors/samplers installed in the field/in rivers;
- validation and uncertainty of model results.
In this context, the objective of this Spring Thematic School workshop is to bring together French and international experts working on these topics together to develop the critical guidance and standardization needed so that sediment fingerprinting and ancillary approaches can be adopted as a utilitarian and readily applicable sediment management and academic tool. Thematic workshops will be organised, drawing on the varied expertise, to set-up a concerted strategy to develop methodological approaches to apportion sediment to its source(s). Original and international experiments will be designed, and an initiative (clearinghouse) will be presented for data sharing. A potential practical contribution of the School could be the publication of dataset(s) in open access to test/calibrate/validate sediment tracing approaches in contrasted environments across the world.
This Spring School is organised to follow-up the discussions initiated during specifically dedicated sessions organised during the last years at the General Assembly of the European Geoscience Union (EGU) and the American Geophysical Union (AGU).
Logistics
The Spring School took place in the Centre Port-Royal, Saint-Lambert-des-Bois, Paris Region, France.
Training format of the Thematic School
The main objective will be to update the participant knowledge of all the state-of-the-art techniques/methodological issues associated with sediment/particle-bound tracing. Most of the experienced researchers (including postdocs) participating to the School will therefore be invited to share their knowledge in their primary field of expertise through the preparation of specifically dedicated lectures.
All participants will be invited to prepare databases to implement some of those techniques/models taught during the School with their own data.
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The following open access database can be used as a template:
Chalaux Clergue, T., Evrard, O., et al. (2022). Organic matter, geochemical and colorimetric properties of potential source material, target sediment and laboratory mixtures for conducting sediment fingerprinting approaches in the Mano Dam Reservoir (Hayama Lake) catchment, Fukushima Prefecture, Japan. Zenodo, 10.5281/zenodo.7081094.
Template files for preparing data and metadata are also available on-line:
Evrard, O., Chalaux-Clergue, T., Bizeul, R., & Foucher, A. (2024). An unified template for sediment source fingerprinting databases (24.03.01) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.10725788 Evrard, O., Chalaux-Clergue, T., Bizeul, R., & Foucher, A. (2024). An unified template for sediment source fingerprinting databases (24.03.01) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.10725788 Evrard, O., Chalaux-Clergue, T., Bizeul, R., & Foucher, A. (2024). An unified template for sediment source fingerprinting databases (24.03.01) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.10725788 Evrard, O., Chalaux-Clergue, T., Bizeul, R., & Foucher, A. (2024). An unified template for sediment source fingerprinting databases (24.03.01) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.10725788 Evrard, O., Chalaux-Clergue, T., Bizeul, R., & Foucher, A. (2024). An unified template for sediment source fingerprinting databases (24.03.01) [Data set]. Zenodo
https://doi.org/10.5281/zenodo.10725788
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All participants will be invited to prepare two slides to present them and their research/background at the beginning of the School.
Significant time slots were also devoted to additional practical workshops and discussions on the potential solutions that could be found to address the methodological problems associated with tracing and design concerted strategies for future research.