The ambition of TEAM’s research work is to better understand the impacts of built environments (cities and transport infrastructures): deterioration of hydric discharges, increase in polluting discharges, rise in local temperature. By understanding and conceiving built environments it is possible to take into account the ecological transition challenges and this helps to define strategies for management, planning and adaptation of these environments.
Contribution to sustainable, resilient, frugal built environments that are pleasant to live in
These challenges are the subject of major public policies, such as the national biodiversity strategy (2011-2020) which advocates a return to nature in cities, or the national Strategy Document for Ecological Transition to Sustainable Development. The new policy for natural source control of storm water is at the heart of these concerns. If it were to be implemented on a large scale this would generate many eco-systemic services, not only for the urban environment but also for the quality of life of citizens.
Protection of receiving environments and water resources
With regard to discharges from built environments, the fight against pollution is currently a major issue. Following the improvement in discharges and treatment of waste water, efforts are now being focused on reducing and treating discharges during rainy weather, with increasing demands being placed on local authorities, who are the contracting authority for sanitation networks. Special attention is concentrated on storm water management, with the aim of setting up infiltration and evapo-transpiration policies that facilitate management of urban storm water from the origin of run-off. Urban run-off water can represent a non-negligible proportion of pollutant discharges into natural environments, due to the nature of the surface materials, the changes they undergo over time and the ways these surfaces are used.
Adaptation to climate change
Built environments are sensitive to nuisance caused by local management decisions and to the consequences of more global changes. Anthropogenic activities and installations bring about local changes to the climate in urban environments, causing a rise in local temperature: this is the urban heat island phenomenon. The resulting heat waves increase the vulnerability of the urban environment: its populations, infrastructures and property. To achieve “mitigation” of this phenomenon it is necessary to implement a range of methods to limit the effects of climate change, as part of storm water management policies: re-naturing impermeable areas, modifying urban morphology, etc. The benefits produced by using these measures still need to be assessed and quantified. In order to draw up a regional adaptation strategy it is first vital to have more comprehensive knowledge of how urban environments are organized, their dynamics and vulnerabilities.
The aim of the TEAM scientific project is to contribute knowledge and develop methods and tools for analysing/representing the modes via which energy, water and the associated pollutants are transferred. Transfer phenomena and their assessment are underpinned by theoretical approaches which require further capitalisation of new knowledge about an environment which is both complex and heterogeneous, by means of inter-disciplinary and even trans-disciplinary approaches, using several spatial scales.
Research work to identify the real performance levels of modern storm water management techniques is being conducted (green roofs, road run-off water retention basins, …). The team’s purpose is to lengthen the operating life of these systems, while guaranteeing and optimising performance assessed by multiple criteria. This is in accordance with the Ministry’s strategy to “avoid, reduce and compensate environmental impacts” which is part and parcel of a sustainable development approach and aims to improve the way in which environmental concerns are taken into account in public sector decision-making. To achieve this, it is necessary to understand how these systems function, and how they change over time. By setting up relevant assessment methods (site instrumentation, physico-chemical analyses, modelling) it will then be possible to identify the optimal conditions for designing and maintaining storm water control systems. This is vital information for managers. The team is focused in particular on an integrated view of the services rendered by the vegetation growing in these systems. This vegetation has a major impact on the multi-criteria performance levels of the management systems.
The TEAM research work is divided into three areas:
A. Multi-scale hydrological functioning of built environments;
B. Pollution of the environments: water/soil/vegetation transfers and treatment structures;
C. Climate regulation processes in the urban environment.
The results of this applied research help to better understand and control the impacts that installations have on water resources, on the quality of the environments (water, soil) and on the local induced climate effects.
Scientific obstacles tackled:
Interactions and feedbacks between the different transfers analysed around built environments. The aim in the measurements performed and the models developed is to combine the investigations to have a complete assessment of the exchanges and quantities at stake in the different relevant compartments (soil, vegetation, atmosphere). This ambition to have an integrated view inevitably increases the complexity of the methods and tools to be developed.
Diversity of the spatial and temporal scales of analysis. The challenges are analysed from the scale of a single structure to the conurbation, and from a few minutes to several decades. In order to understand crucial processes, it is occasionally necessary to adopt even more detailed scales of analysis. What is the appropriate spatial scale to analyse a particular process? How can local results be transferred to larger spatial scales?
The role of vegetation in the different transfers. As vegetation returns to built environments, the specific features of these environments are going to modify plant phenology. These modifications are understudied at the level of the individual plant: plants are singular, for ornamental reasons and to facilitate upkeep; soils in urban areas transport heterogeneous flows and may be polluted; the boundary layer of the atmosphere in cities is considerably modified (increased roughness, more turbulent flows, highly variable lighting conditions).
For Area A
Multi-scale hydrological functioning of built environments
- Acquisition of a detailed understanding of hydric transfers: study of evapo-transpiration and its influence on the behaviour of plant cover;
- Study of hydrological performance of techniques for source control of urban storm water: simulation of the functioning of structures, quantification of their performance;
- Modelling integrated at the scale of the district: understanding the impacts of installations on different components of the water cycle on the scale of a district, influence of control structures.
For Area B
Pollution of the environments: water/soil/vegetation transfers and treatment structures
- Understanding the behaviour of (micro)pollutants: functioning of storm water management systems, characterisation of pressure of targeted pollutants, assessment of the associated vulnerability;
- Design and assessment of the performance of management techniques: mechanisms for retaining pollutants, role of vegetation and soil in transfers of pollutants in vegetated control structures, platform for demonstration/assessment of run-off water management techniques.
For Area C
Climate regulation processes in the urban environment
- Interaction between the hydric and climatic processes impacted by urban development: understanding of changes in combined hydro-climatic performance levels of urban installations, in particular when they are vegetated;
- Enrichment of multi-scale climate diagnosis methods (building → district → city): in-depth analysis of SVAT model parameters, development of empirical climate models on the scale of an urban fragment, methodology for use of climate maps within urban documentation.
Partners from the public sector and the supervisory ministries’ scientific and technical network: ENTPE, UGE, Météo-France-CNRM, CSTB, École des Ponts – ParisTech, EFFICACITY
Academic partnerships: Univ. de Lorraine, Univ. Paris-Sud Orsay, Univ. de Strasbourg, Univ.Toulouse, Univ. de Versailles Saint-Quentin, ENGEES,CNRS, INRAE, AgroParisTech, IRSTV, ENSAIA
Ahmeda Assann OUEDRAOGO (2020-2023), Estimation de l’évapotranspiration sur des ouvrages de gestion à la source des eaux pluviales. Ecole doctorale SI2E ENPC. Directrice de thèse : Marie Christine Gromaire (laboratoire LEESU) ; encadrant : Emmanuel Berthier (Cerema, TEAM)
Thomas Villemin (2019-2022), « Modélisation des échanges énergétiques entre la surface d’une toiture végétalisée extensive et un panneau photovoltaïque », Ecole Doctorale SIMPPÉ – Univ. de Lorraine. Directeur de thèse : Gilles Parent (Univ de Lorraine), co-directeur de thèse : Rémy Claverie (Cerema).
Mithun HANUMESH (2018-2021), « Impact du vieillissement de substrats de toitures végétalisées sur leurs performances hydriques et thermiques », École Doctorale SIReNA – Univ. de Lorraine. Directeur de thèse : Geoffroy Seré (Univ. de Lorraine), co-directeur de thèse : Rémy Claverie (Cerema)..
Gwendal LIBESSART (2022), «Modélisation prédictive de la qualité des sols urbains basée sur l'évolution de l'occupation des sols», École Doctorale SIRENA – Univ. de Lorraine. Directeur de thèse : Christophe Schwartz (Univ. de Lorraine), encadrement : Catherine Franck-Néel (Cerema), Philippe Branchu (Cerema).
William POPHILLAT (2022), « Conséquences d'une systématisation des pratiques d'infiltration à la parcelle des pluies courantes à l'échelle du quartier – Apports de la modélisation intégrée », École Doctorale Terre Univers Environnement – Univ. Grenoble Alpes. Directeur de thèse : Fabrice Rodriguez (IFSTTAR), encadrement : Isabelle Braud (INRAE), Jérémie Sage (Cerema)
Tala KANSO (2021), « Mesure et modélisation du bilan hydrologique de dispositifs rustiques de gestion à la source des eaux de ruissellement de chaussées », École doctorale SIE– Univ. Paris-Est. Directrice de thèse : Marie-Christine Gromaire (École des Ponts ParisTech), co-directeur de thèse : Ghassan Chebbo (Université Libanaise), encadrement : David Ramier (Cerema).
Lucie VARNEDE (2020), « Des parkings perméables végétalisés pour une gestion durable des eaux pluviales urbaines », École doctorale SIE– Univ. Paris-Est. Directrice de thèse : Marie-Christine Gromaire (École des Ponts ParisTech), encadrement : David Ramier (Cerema).
Lucie BARBIER (2019), « Dynamique des flux de fondants routiers et influence sur la pollution routière au sein d'un bassin de rétention-décantation », École doctorale SIMPPÉ – Univ. de Lorraine. Directrice de thèse : Marie-Odile Simonnot (Univ. de Lorraine), co-directrice de thèse : Ivana Durickovic (Cerema).
Rémi SUAIRE (2015), « Dynamique de transfert des fondants routiers dans un bassin de rétention des eaux de ruissellement routières : vers une solution d'assainissement par phytoremédiation », École Doctorale RP2E – Univ. de Lorraine. Directrice de thèse : Marie-Odile Simonnot (Univ. de Lorraine), co-directrice de thèse : Ivana Durickovic (Cerema).
Li YINGHAO (2015), « Modeling of hydrological processes of an urban catchment : Study of a saturated soil flow module and applicatsion to an urban development zone of the future Paris-Saclay University », École Doctorale SPIGA – École Centrale de Nantes. Directeur de thèse : Fabrice Rodriguez (IFSTTAR), encadrement : Emmanuel Berthier (Cerema).
Ryad BOUZOUIDJA (2014), « Fonctionnement hydrique d'un Technosol superficiel – application à une toiture végétalisée », École Doctorale EMMA – Univ. de Lorraine. Directeur de thèse : David Lacroix (Univ. de Lorraine), encadrement : Geoffroy Séré (Univ. de Lorraine), Rémy Claverie (Cerema).
François LECONTE (2014), « Caractérisation des îlots de chaleur urbains par zonage climatique et mesures mobiles : Cas de Nancy », École Doctorale RP2E – Univ. de Lorraine. Directeur de thèse : Mathieu Pétrissans (Univ. de Lorraine), encadrement : Julien Bouyer (Cerema), Rémy Claverie (Cerema).
Julie SCHWAGER-GUILLOUX (2014), « Les toitures végétalisées, puits et sources d'éléments en traces métalliques », École Doctorale RP2E – Univ. de Lorraine. Directeurs de thèse : Jean-Louis Morel (Univ. de Lorraine), Véronique Ruban (IFSTTAR).