United Kingdom Sullivan C.A. and J.R. Meigh. In a transboundary context, the riparian countries have to agree upon the scope of the study but also on the definitions to be used. A key element in this step is defining the vulnerability indicators and critical thresholds. This choice depends on the scope of the study and the water management objectives and is needed to assess the direction and magnitude of the changes affecting the system. This understanding should be used in further adaptation policy and planning. These stakeholders are identified in the first step of the VA.