Understanding and characterizing complex risks with Impact Webs: A guidance document

This guidance document provides “how to” instructions for the development of Impact Webs. Impact Webs are a novel methodological tool which are designed to better understand and characterize complex risks, such as compounding, cascading and systemic risks. Understanding the complexity of risks, including possible compounding, cascading and systemic effects, is a key step in reducing and managing disaster risks, as recognized also in the Sendai Framework for Disaster Risk Reduction.

This document outlines the rationale for Impact Webs and the steps for co-creation and use. Impact Webs can be a powerful tool for understanding complex risks as they allow for an in-depth analysis of risks while accounting for their interactions within the systems in which they exist. Impact Webs can be used to provide guidance for data-driven risk assessment and to identify risk management options.