Visualisation of User-Generated Event Information: Towards Geospatial Situation Awareness Using Hierarchical Granularity Levels

In recent years, enterprises and emergency response teams have started to use user-generated content to monitor crises, events and trends. Especially in critical situations, decision makers must, above all, quickly assess huge amounts of data. Effective geographical visualization and aggregation of collected data is an important prerequisite to enable decision makers to infer the impact of a detected event on, for example, their supply chains and other physical establishments. However, in existing literature the aspect of geographical visualization of automatically analysed events is hardly addressed. In this paper, we propose to introduce hierarchical levels of detail, a concept from Geographic Information Systems, for the visualization of user-generated data describing a local event. We developed a tool which can improve the assessment of regional impacts by offering the possibility to browse and visualize results on layers aggregating data along individually defined hierarchical dimensions, e.g. geographical or political districts.