The key to successful decision support is the ability to test and explore alternative options. Users are able to pose "What if" questions to the system, for example, "What happens if a levee breach occurs?", "Does it make sense to install mobile protection barriers next to the hospital?", or "Can we guarantee the completion of all barriers in time if we employ 30 workers and two trucks?". In Visdom, the synergy of modules for simulation, analysis, and visualization provides the user with the answers to such questions. In dedicated visual representations, users can observe the effects of their decisions, for example, a flood extent or an expected damage to important infrastructure.

Our most advanced application concerns flood and stormwater events. It uses a GPU-based inhouse 2D shallow water solver in combination with a sewer network simulation to model different hydrodynamic phenomena. Apart from that, we are working on the integration and coupling of simulation models for rainfall-runoff computation, logistics, and agent-based models for pedestrians and traffic to provide broader applicability of our generic decision support in the environmental domain.