TEAM: Transfers and interactions linked to water in built environments

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).