Risk Nexus: Making communities more flood resilient: the role of cost-benefit analysis and other decision-support tools

Making the case for pre-event disaster risk reduction Large-scale flood disasters in recent years vividly demonstrate the need to invest in risk reduction measures before such events happen. It can be difficult, however, for a community to decide to invest in such measures, as these decisions usually involve several options and multiple stakeholders with different short- and long-term objectives and priorities. As a result, intense discussions often produce little real progress, or there is simply a return to the status quo. A variety of decision-support tools are available to organize and evaluate options, which can assist in making the case for pre-event risk reduction to flooding and other hazards. Among these tools, the most widely-used for assessing flood risk reduction measures is cost-benefit analysis (CBA). Other tools that can be used to aid decisionmaking include cost-effectiveness analysis (CEA), multi-criteria analysis (MCA) and robust decision-making approaches (RDMA). In this issue brief we outline three key findings that provide information for research, policy, and implementing decisions on reducing flood risk. The analysis provides a foundation for work under the Zurich flood resilience alliance, allowing it to integrate a decision-support toolbox for community activities focused on implementing flood risk reduction in different parts of the world. This publication is based on a white paper developed by two members of the alliance, the International Institute for Applied Systems Analysis (IIASA) and the Wharton School’s Risk Management and Decision Processes Center at the University of Pennsylvania (Wharton). It is available at: http://opim.wharton.upenn.edu/risk/library/ ZAlliance-decisiontools-WP.pdf.