Advancing Hydropower Risk Assessment: From a Direct Risk Model (BIRMM) to a Cascading Risk Model (BIRMM-2)

Traditional risk assessments for large-scale water projects often fail to capture the complex, cascading effects where one impact triggers a chain of others. This paper introduces the enhanced Bayesian Integrated Risk Mitigation Model 2 (BIRMM-2), a significant advancement of the previously published Bayesian Integrated Risk Mitigation Model (BIRMM). While BIRMM provided a dynamic framework for evaluating direct socio-environmental risks across a project’s lifecycle, it did not explicitly model systemic interdependencies. BIRMM-2 enhances this framework by incorporating interdependency and divorcing nodes to quantify the cascading (indirect) pathways that amplify risk. Applied to the Balakot Hydropower Project (BHP) in Pakistan, BIRMM-2 reframes risk prioritization from symptoms to root causes. Unlike the direct-risk model, which ranked immediate socio-economic losses highest, BIRMM-2 identifies physical triggers like “spoil dump failures” as the primary systemic risk due to their cascading impacts on water quality, ecosystems, and community livelihoods. This systemic approach provides a more robust and actionable tool for sustainable water and environmental management in complex infrastructure projects.