Many Command& Control or Early warning systems have been developed providing access to large amounts of data (and metadata) via geo-portals, or by accessing predefined data sets relaying on Spatial Data Infrastructure. However, the users involved in emergency response are usually not geoinformation specialists and they lack deep understanding about the spatial data structures and corresponding terminology. Semantic web and knowledge engineering approaches applied to geo-data can bring significant improvements in these directions. This paper presents a formal modeling for the emergency management as performed in the Netherlands. Having the tasks of the actors well specified, it is possible to define the geo-information needed for completing the task.