Issues and needs
Combined with climate change, the artificialisation of urban land is exposing our cities to a range of phenomena (urban heat islands or UHIs, flooding, biodiversity loss, etc.) that are detrimental to the comfort, well-being and, more generally, the health of city dwellers. These phenomena are likely to be exacerbated by soil sealing, which is a major artificialisation process.
Desealing addresses a number of issues relating to the water cycle, adaptation to climate change, biodiversity and the well-being of residents. As a step towards renaturation, desealing helps to meet the ZAN (zero net artificialisation) objectives. A large number of desealing initiatives have been undertaken.
However, these initiatives must not overlook the environmental risks linked in particular to the exposure of soil pollutants (which could give rise to health risks, for example in school playgrounds) or their transfer into groundwater. The presence of soluble rocks or other factors that can increase geotechnical instability or the risk of flooding by rising groundwater should also be taken into account.
Major criteria for the feasibility of soil desealing.
© Désiville
Results and use
The guide provides a methodological framework for mapping the potential for soil desealing on the basis of nationally available data, with the possibility of using more precise local data. The resulting maps can be used as a basis for developing desealing strategies, as a communication or discussion tool or as a decision making aid. A decision tree is used to check that the various feasibility criteria have been taken into account.
The available range of desealing solutions enables appropriate action to be taken on projects at any scale to obtain the different environmental and social benefits sought. However, the environmental constraints associated with desealing (e.g. soluble rock, soil pollution and rising groundwater) must be assessed. The catalogue identifies the advantages and constraints of the various desealing solutions. The technical data sheets and comparisons are designed to help you choose the most appropriate solutions.
BRGM's role
BRGM managed the project on behalf of the Urban Science and Technology Research Institute (IRSTV - FR CNRS 2488). It also managed methodological tests carried out to map the potential for soil desealing and organised workshops with local stakeholders for jointly establishing methodologies. BRGM advanced the method of mapping soil pollution hazards on a regional scale and developed work on mapping the capacity for soil infiltration. It also helped to draw up a catalogue of desealing solutions and to promote and disseminate the results.
Partners
Partners in the Désiville soil desealing project.
© Désiville
