H2O'Lyon Boosters

Pollution caused by floods

1.4 billion people in the world are exposed to the risk of flooding, making it one of the main natural risks on a global scale. Concern about these phenomena is all the greater because of the intensification and increase in extreme climatic hazards, as identified by the sixth IPCC report (2021).

In an urban context, flooding is a particularly dramatic phenomenon due to the diversity and number of urban issues (population density and activities, social and technical vulnerabilities, urban materiality, etc.). The demographic projections announcing that two thirds of the world's population will be in an urban context by 2050 (United Nations, 2019) reinforces the need to study and better understand these phenomena.

Until now, the main risks studied in the context of urban flooding concern (1) the transport of people or materials by water, (2) the disruption of networks (transport, supply, etc.) and (3) the difficulties of representing the domino effects of a natural disaster for populations.

Our booster focuses on an additional risk that has been little studied: the dispersion of pollutants. Contamination can occur through overflowing sewerage systems, through transport by accidental spills (trucks, tanks, etc.) or through leaching. The pollutants can then be transported, dispersed in the streets and/or deposited in certain buildings.

This booster uses approaches from the humanities and engineering sciences to provide answers to two questions:

1/ How are potential pollutions perceived as a problem by societies?
Thesis by Maïlys Genouel (EVS) 2021-2024

• Is urban flooding pollution a social or public problem?

• What are the dysfunctions and adaptations observed at the neighbourhood level?

• What are the physical processes responsible for the dispersion of pollution in an urban context?

For this purpose, the MURI model (Urban Model for the Study of Flood Risk) of the Hydraulics and Hydro-morphology Laboratory (HHlab) of INRAE Lyon will be used. This model reproduces typical flows of flooded street networks with the possibility of adding pollutant discharges at different locations in the city.

• What are the abilities of operational digital flood management tools to reproduce these dispersions?

Scientific team :

• Emmanuel Mignot (LMFA, INSA de Lyon)
• Sébastien Proust (Riverly – INRAE de Lyon)
• Emeline Comby (EVS – Université Lyon 2)
• Yves-François Le Lay (EVS - ENS)

Partners :

• Benjamin Dewals (University of Liège)
• Catherine Trudelle (Université du Québec à Montréal (UQAM))
• Co-financement des thèses par l’Ecole Urbaine de Lyon
• Réseau Inondations InterSectoriel du Québec
• ARTELIA

The setting up of two PhD theses in parallel, one in engineering science (Clément Fagour) and the other in social sciences (Maïlys Genouel) allows constant back and forth between, on the one hand, the identification of the state of knowledge on past events and on pollution management practices and, on the other hand, the identification of dispersion processes in flooded cities.

This strategy of conducting research on the same subject in parallel, using two very different approaches, offers the potential for greater efficiency, with, in particular, a crossover of scales over the period of the two theses (from the scale of the city to the scale of the building block or street for the geographical approach; from the scale of the block to the scale of the city district for the experimental and numerical modelling approach).

To learn more about this project, take a look at Clément and Maïlys' work in the section poster !

Trajectory(s) of the Saône-Rhône hydrosystem in the Palaeoanthropocene and the search for similarities with current climate warming

One of the most important debates in our societies is how to understand our environmental future (conservation, restoration, adaptation, mitigation) in the context of ongoing climate change. Archaeologists, historians, geographers and palaeo-environmentalists, using an interdisciplinary and retrospective approach, can make a major contribution to this question.

As far as hydrosystems are concerned, the impact of climate change on water resources is compounded by that of the anthropisation of the environment, which has been accentuated since the Palaeo-anthropocene. The Saône-Rhône basin is a case in point, with hydraulic developments that have contributed to its artificialization, with all its consequences (changes in the flow-load ratio, transformation of alluvial ecosystems, decline in biodiversity, etc.). However, until now, the study of the short term has prevailed in this basin (see ZABR, OSR, OHM, OTHU, etc.).

The aim of this booster project is to analyse the trajectory of the socio-ecosystems of the rivers of the Rhône by comparing short and long timescales, discussing the cumulative effects of climatic and anthropogenic forcings since the beginning of the Palaeo-anthropocene, and the correlative connectivities/disconnectivities of the hydrosystem along the Saône-Rhône corridor. The goal is to build retrospective scenarios, but also to advance our knowledge of the main historical bifurcations in the trajectory of a continental hydrosystem such as the Rhône and the potential societal adaptations/remediations.

This booster uses approaches from the human sciences (geomorphology, geomatics, archaeology, history, etc.) and the environmental sciences (geophysics, geochemistry, isotopy, palaeobotany, modelling, etc.) to provide answers to a number of questions concerning the socio-environmental trajectory of the Saône-Rhône hydrosystem since the Neolithic period (7500 years ago):

1/ How have the settlement cycles of river areas been organised since the Neolithic period? How have riverside societies responded to fluvial metamorphoses, phases of incision and extreme events?

2/ How can we restore the evolution of watersheds/rivers in the light of our knowledge of land-use patterns, farming practices and techniques, and successive landscape structures, which influence the methods of transferring sediment flows along the watershed/river system continuum? Are there successive thresholds in the environmental history of the Rhone basin that could be identified using a systems approach?

3/ How can we assess the impact of increasing human activity on river hydro-ecosystems since the Neolithic period? What markers should be used to trace their history (soil erosion, vegetation degradation, organic or metallic palaeo-pollution, etc.)?

These questions are fuelled by a multi-parameter, multi-sediment archive analysis. The project focuses on river beds, hydraulic infrastructures and, more generally, riverside urban areas, emphasising adaptations to the main hydro-sedimentary changes (temporal trajectory), such as periods of generalised incision of hydrosystems or accelerated rise in the river floor, associated with metamorphosis of river beds. Research is being carried out into the development of alluvial plains since Protohistory, along increasingly artificial river corridors (dykes, canals, dams, drainage, etc.), in collaboration with preventive archaeology surveys and excavations

This project is associated with the creation of an interregional Projet Collectif de Recherche (PCR) by the French Ministry of Culture. It also benefits from research carried out as part of the thesis of Theo Martinez (IFPEN, Univ Lyon 2) focusing on modelling the construction of the Rhône delta in relation to the past dynamics of its catchment area and paleoclimates.

Scientific team:

- EVS (Univ Lyon 2, Lyon 3, CNRS) : J-F Berger, E Cossart, M Fressard, K Michel, B Chaize, A Christol, J Lejot, A Barra, F Perret
- INRAP Auvergne-Rhône Alpes et PACA : B Lecomte-Schmitt, O Franc, E Durand, R Guilbert/Berger
- Service archéologique de la ville de Lyon : H Tronchère, S Gaillot
- Archéorient (Univ Lyon 2, CNRS) : H Delile, N Jacob
- Chrono-Environnement (Univ Franche-Comté, CNRS) : D Sordoillet, I Jouffroy-Bapicot, O Girardclos
- Artehis (Univ Bourgogne, CNRS) : R Landois, J-P Garcia, A Quiquerez
- LEHNA (Lyon 1, ENTPE) : A-M Dendievel, B Mourier, T Winiarski, M Hamada, D Donzé
- IFP Énergies nouvelles : R Deschamps, G Ducret, T Martinez
- ASM (Montpellier 3, CNRS, INRAP) : E Durand, M Rué
- ISTerre (Univ Grenoble-Alpes, IRD) : L Audin ; A Gourlan
- Paléotime : M Rué

Parners:

- A Lafont-Chardin (Ciham), J Argant (LAMPEA), J Blichert-Toft (Geologie de Lyon), J Duriaud (GRAT), A Dabrin (Riverly-INRAE de Lyon), PG Salvador (TVES), S Bleu (UMR ARAR)
- Institut national en archéologie préventive (PACA et ARA), Service régional de l’archéologie Auvergne-Rhône Alpes, Service régional de l’archéologie Bourgogne-Franche Comté, IFP Énergies nouvelles, Conseil de département de l’Isère, Service du patrimoine-Ville de l’Isle-sur la Sorgue
- Groupe de Recherche Archéologique de Tournus (J Duriaud, M Rué)

• Geoarchaeology and continental hydrosystems" field course:

Since autumn 2022 (and for 5 years), this booster has been associated with a field placement as part of the Geonum master's programme and supported by H₂O'Lyon. This internship is supervised by Kristell Michel, Jérôme Lejot and JF Berger with the help of the master's team and the OMEAA-EVS platform. After 2 days in the field, the students process the data acquired (≈40 hours per group of 4-5 students over a period of 2 to 4 months), and produce a scientific report. They work on several hypotheses proposed by the research team, based on multidisciplinary sources (fluvial geomorphology, archaeological and historical sources) and data acquired in the field using different metrology equipment (GNSS, DGNSS, drone imagery). On the basis of the results obtained, new working hypotheses are formulated based on the collation of spatial data. These proposals will be the subject of a final collective report and the preparation of a poster to be presented at the annual H₂O'Lyon conference.

• TP Laboratory of the Master in Environmental Management (Univ Lyon 2, Lyon 3, ENS-Lyon)

The Master 2 students are immersed in an integral multi-proxy study of a Rhône river core during 5 4-hour practical sessions (JF Berger, A Barra and H Delile). They learn how to describe a core, devise a sampling strategy, then apply various sedimentological and geochemical analysis protocols, and finally analyse the dataset produced during the last practical session (age-depth model, choice of ratios, PCA, inter-comparison of curves, etc.)..

• Master's internships

Each year, the booster's scientific teams offer work placements for Master 1 and 2 students in the various windows of the project, in association with non-academic partners (INRAP, departmental councils, urban heritage services, etc.).

Urbanisation of floodplains

By 2050, 68% of the planet's 11 billion inhabitants will be urban. Widespread urbanisation is one of the main threats to global biodiversity, exposing humans to increased risks (health, pollution, flooding, etc.). In this context, floodplains, which cover less than 3% of the Earth's surface, are the 'attractors' and 'fixers' of global urbanisation. A large proportion of the world's population has lived, lives and will continue to live on floodplains, which are essential ecosystems for human well-being and for sustaining life on Earth, but which are also one of the most vulnerable ecosystems. Over time, mankind has helped to modify the alluvial plains, their landscapes, the rivers that flow through them and the associated ecosystems. However, the extent of human-induced changes and impacts on the biodiversity, functioning and ecosystem services of alluvial plains has never been quantified on a global scale.

The GloUrb (Floodplain urbanisation at global scale) booster seeks to fill this gap and quantify the environmental consequences of urbanisation on floodplains on a global scale. By drawing on different disciplines and using a synoptic and retrospective analysis of the last four decades, the aim is to assess current conditions and monitor future changes.

Scientific team

• EVS (CNRS, ENS-Lyon, Univ. Lyon 3) : H Piégay, B Belletti, G Pinay, L Vaudor, M Cottet, M Lussault, Y-F Le Lay, V Chiu, S Dunesme, L Rey
• ENS-LP (CNRS, ENS-Lyon) : P Jensen, N Pustelnik, P Abry, P Borgnat , S Roux
• LEHNA (Univ. Lyon1): B Kaufmann, S Doledec, F Colas
• GATE (Univ. Lyon 2): P Polomé
• TETIS (INRAE, CNRS) : E Barbe, C Weber, K Ose, D Ienco, F Cernesson, N Guiffant

Internationa Scientific Committee

• J Opperman (WWF, Global);
• A Chin (Univ. Colorado Denver, US);
• S Yepez (Univ. Coception, Chili);
• V Jain (IIT Gandhinagar, Inde);
• Z li (Univ. Wuhan, Chine);
• P Gao (Univ. Syracuse, US);
• D Ouketou-Tarazewicz (Univ. Omar Bongo, Gabon)

This booster also falls within the scope of ”Water and Urban Worlds”.

Theses, postdoctorates and master's internships in clusters

It is planned to recruit three PhD theses (two co-funded by EUR H2O'Lyon and LabEx IMU), three post-docs and 9 Masters students, who will work in close collaboration with each other as well as with the scientists involved and the international partners, to form a sort of meta-cluster for the booster.
The three theses will focus on signal analysis, landscape ecology and digital geography. The PhD students and postdocs will also be involved in EUR activities (doc/postdoc workshop evenings, co-supervision of Masters courses, mentoring of M1-IWS students).
For at least two years, the booster's scientific teams will be offering internships for Masters 1 and 2 students within the project's various tasks (particularly in signal analysis, hydrology, environmental risk economics and comparative law), in association with non-academic partners and with international links (WWF and other environmental associations, particularly in the US, India and Europe).

TP/TD module within one of H2O’Lyon's Masters(Environmental Management, Water Sciences or Digital Geographies; Lyon 1, Lyon 2)

The PhD students and post-docts involved in the GloUrb project are expected to participate in the development of a geomatics TP/TD module for: the selection of cities located on alluvial plains; the identification of the urban spot; the validation of the results obtained by remote sensing on the socio-environmental impacts caused by the global urbanisation of alluvial plains.