A web-based multi-hazard risk simulation service based on impact chains

There is a need for the development of databases for representing the complex hazard interactions and cascading impacts of multi-hazard extreme events, such as sequences of earthquake or storm-related events. The concept of impact chains has proven to be a useful concept for conceptually representing the risk related to such complex events, but applications have been mostly used for visualization purposes only.  In the context of the EU PARATUS project, a web-based simulation service is being developed for first and second responders and other stakeholders to evaluate the impact and risk related to multi-hazard events building upon a representation of scenario risk through impact chains. The simulation service includes a series of tools to gather, integrate, and develop new hazard and risk information. The central tool is the impact chain builder, where users can develop their own impact chain of past events, or future disaster events, and is used as a basis for quantifying direct damage and prioritizing secondary losses in different sectors. Several tools for hazard assessment will provide fast estimations of multiple hazards and can be linked to the impact chains. One of these is the FastFlood tool which allows to generate flood extent and depth maps for any area, within seconds, based on global datasets, or more detailed user-supplied data. The tool can also be used to evaluate the effect of risk reduction measures. Also, hazard tools for other processes are developed such as for mass movements, with initiation and runout components and linked to flood events. The hazard data is combined with elements-at-risk data, for exposure analysis in the RiskChanges tool. This tool allows to quantify losses, using a database of vulnerability functions. Multi-hazard losses are calculated using specific combination rules for different hazard interactions. The tool can also be used for evaluating optimal risk reduction alternatives, where the risk components are re-analyzed and the risk reduction is compared with investment in a cost-benefit analysis. Changes in risk for future scenarios, related to climate change, land use change, and population change, for certain future years, can also be analyzed using the tool. Other tools are still under development, such as a tool for collaborative planning. The exact number of components and the final structure of the platform will be determined iteratively through a series of stakeholder consultations, following a user-centered design. The platform is designed flexibly to be able to support stakeholders that work in different sectors, geographic settings, and interacting hazards, and at the same time to address (a number of) their needs for analyzing the impact of compounding multi-hazard events with cascading impacts.