Prospective integrated modelling of water scarcity risk in western Switzerland: lessons learned and new challenges for water security assessment

Water security is an emerging concept, whose assessment and quantification are under development, and of which water scarcity can be considered as a basic research need. This paper draws on four research projects conducted by the authors in western Switzerland and has five key messages: (i) scenarios that account for both hydro-climatic and socio-economic changes are necessary to grasp their respective impacts on water scarcity; (ii) the spatial and temporal resolution of integrated models need to be adapted to the issue tackled; (iii) the involvement of stakeholders in co-producing future water demand scenarios and testing the capacity of plausible adaptation strategies to reduce water tensions is needed to increase the plausibility of modelled situations; (iv) hydrological approaches must evolve towards a geographical integration of territories, in particular to better grasp the different water users, and (v) interdisciplinary research is necessary to assess both the quantity and quality of water resources, and to include both social and governance processes in modelling. Rooted in a comprehensive perspective, the authors argue that such methodological developments would help move towards a dynamic and prospective view of water security.