Thematic School Tracing 2021

TRACING 2021

Emerging strategies of sediment and contaminant tracing in catchments and river systems

(initially planned from 11 to 15 May 2020, postponed following the covid-19 outbreak)

The School took place from 3 to 7 October 2021

View of the group in the main meeting room. A (part) of the group picture outside... Cultural visit of the former Port-Royal-des-Champs Abbey

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)

Local organization committee : Sophie Ayrault (LSCE), Cécile Quantin (Géosciences Paris-Saclay)

International support organization committee: Allen Gellis (USGS), Jean Minella (UFSM, Brazil), Tales Tiecher (UFRGS, Brazil)

With the financial support of the following institutions

This event is supported by the IPSL - Climate Graduate School which is funded by the French National Research Agency - ANR (ANR-11-IDEX-0004 - 17-EURE-0006).

The Thematic School will also present the activities of MITATE Lab, an International Research Project funded by CNRS to conduct pluridisciplinary post-accidental studies in Fukushima.

Outputs of the TRACING School

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, in press). 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).

Audience

Researchers/lecturers, postdoctoral fellows, PhD students.

The candidates were selected based on their CV and motivations to get trained to sediment tracing techniques.

The official language of the Spring School was English.

Logistics

The Spring School took place in the Centre Port-Royal, Saint-Lambert-des-Bois.

The cost for meeting rooms, acccommodation and meals was covered by the School for the selected participants.

Access by train was possible (station ‘Saint-Rémy-lès-Chevreuse') via the RER B suburban train line, directly connected to both airports of Paris (Charles-de-Gaulle and Orly) and easily accessible from the City of Paris and the high-speed train/TGV station of ‘Massy-TGV’.

From this station, a shuttle service was organised to the Centre Port-Royal on 3 October (a similar arrangement was made on 7 October from the centre back to Saint-Rémy station).

All transport itineraries were te be found on the following link:

https://www.iledefrance-mobilites.fr/en

Participation cost

Thanks to the sponsors, the participation to the Thematic School (including accommodation and meals) was free of charge for those selected/invited participants. Only the transport cost to/back from the School was supported by the participants.

Training format of the Thematic School

The main objective was 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 were therefore invited to share their knowledge in their primary field of expertise through the preparation of specifically dedicated lectures.

All participants were invited to prepare databases to implement some of those techniques/models taught during the School with their own data.

All participants were 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.

Programme of the Thematic School

Final version (September 2021)

Tracing2021_Final_210927.pdf

Contact

#310 - : 14/07/2022