Assessment of Life Loss and Early Warning Strategies under Cascading Failures of Cascade Dams
Peng Ming
Ji Sitong
Sun Rui
Zhu Yan
Yang Ge
Cao Zijun
Bai Zewen
Abstract：Cascading failures of cascade dams significantly amplify downstream life risk due to the flood magnification effect,highlighting the urgent need for a systematic framework for risk assessment and early warning decision-making.This study proposes an integrated analytical framework that couples flood evolution simulation,life loss estimation,and early warning optimization.A two-dimensional hydrodynamic model is employed to simulate cascading dam-break scenarios based on breach parameters of different dam types and high-resolution terrain data.The HURAM model is used to quantify life loss rates across varying risk zones.Furthermore,a response relationship between early warning lead time and total evacuation loss is established to identify the optimal warning strategy.Using the Qingjiang River Basin as a case study,a hypothetical scenario involving three sequential dam failures triggered by a 1-in-1 000-year flood is simulated.The results demonstrate that the proposed framework enables comprehensive life loss risk assessment and informed early warning decisions under cascading failure conditions.Compared to single dam failure,cascading breaches increase peak flood discharges by 8.29%at Geheyan and 47.05%at Gaobazhou.However,due to the influence of upstream dam structures and U-shaped valley topography,local flood attenuation occurs despite upstream water level rise.The two-dimensional model captures terrain and velocity distribution more accurately,resulting in an approximately 5.3%increase in estimated life loss risk relative to the one-dimensional model.To minimize evacuation loss,the optimal early warning time is determined as 3.4 hours before Gaobazhou dam failure,reducing total economic loss to approximately 870 million CNY.The results highlight that the flood amplification effect is constrained by both terrain and dam structure,while life loss is highly sensitive to non-linear interactions with hazard parameters such as water depth.This study provides a practical approach and theoretical foundation for cascading dam failure risk management.
Keywords：cascade damscascading failurelife loss assessmentearly warning decision-makingflood magnification effectengineering geology
Publication Date：2025-10-30
Online Publishing Date：2025-11-11(First online date of this platform, not the publication date of the document)
Pages：19( 3776-3794 )