Measuring the experts’ perception about the suitability of natural disaster risk mitigation solutions using minimal risk assessment information, a Multi-Criteria Decision Analysis approach

Finding a sustainable solution to disaster risk mitigation needs to consider different aspects of the disaster’s impact along with social, economic, and physical characteristics of the region. In this regard, a desirable solution for disaster risk mitigation for a region is the one tailored to the local characteristics. These local characteristics not only help measure the different aspects of a disaster impact but also portray existing pressing issues as priorities. While the former can be modeled using risk and resilience assessment models, the latter can be measured from experts’ points of view. Ultimately, the combination of the expert’s perception on important issues and the output of risk and resilience assessment models can be used to evaluate the optimality of each disaster risk mitigation solution.

In this research, a Multi-Criteria Decision Analysis (MCDA) framework is developed to provide an evaluation of each disaster risk mitigation. The developed framework is designed to be able to run on the action-outcome results from risk and resilience assessment models and the cardinal ranking of the decision criteria, representing decision-makers’ expert opinion on the priorities in mitigating and managing disaster risk. The developed MCDA framework is very practical as it can run on action-outcome results, and these results are accessible from a large variety of risk and resilience assessment models. Furthermore, the developed MCDA framework takes into account the uncertainty in the risk and resilience assessment models. In compatibility with running on minimal available information, the MCDA’s decision model is simplified to one layer with a single layer of the decision criteria.

Additionally, as the number of competing mitigation solutions might increase rapidly in practice, the MCDA framework is developed to handle a huge number of alternatives more efficiently and with relatively limited computational resources. The MCDA framework is developed based on the CAR method of eliciting the preferences among mitigation alternatives. The final results evaluate the competing disaster risk mitigation solution based on available data (as processed by risk and resilience assessment models) and the expert’s opinion on important issues and their preferences on the important aspects of disaster impact. As such, the final results provide an estimation of the expert’s belief on the desirability of each of the disaster risk mitigation solutions.

This MCDA framework is developed as part of the Horizon Europe project MEDiate (Multi-hazard and risk-informed system for Enhanced local and regional Disaster risk management). This project is dedicated to creating a decision-support system (DSS) for disaster risk management that not only takes into account the complexities of multiple interacting natural hazards but also tailors the final solution to the characteristics, priorities, and concerns of the local communities and decision-makers. The MEDiate framework is implemented on four different testbeds (Oslo (Norway), Nice (France), Essex (UK), and Múlaþing (Iceland)), each of which has a different multi-hazard pair and different socio-economic characteristics. The deployment of the developed MCDA framework on different natural hazards and socio-economic characteristics shows its flexible practicality.