Research on rapid assessment method of barrier lake outburst risk based on comprehensive index system

Dammed lake outburst floods are characterized by strong suddenness, high destructiveness and short emergency response time. Traditional numerical simulation methods are difficult to meet emergency decision-making demands due to high data requirements and long computation time. This paper aims to construct a rapid dammed lake outburst risk assessment model with acceptable accuracy and timeliness, so as to provide decision support for emergency responders in disaster scenarios. On the basis of the traditional four-module system (dam stability, flood severity, exposed population, life loss), a new module of early warning response and social vulnerability is introduced to form a five-module comprehensive rapid assessment framework covering natural processes and social responses. The model takes a small number of available geometric, hydrological and social behavior parameters as input, and quantifies risk values through standardized scoring functions. The CRITIC (Criteria Importance Through Intercriteria Correlation) method is adopted to calculate objective weights and eliminate human subjective bias. The model is calibrated and verified using measured data from more than ten typical barrier lakes including Tangjiashan, Baige, Donghekou, Xiejiadianzi and Xiaojiaqiao. The model outputs of dam stability, flood peak discharge, exposed population and life loss are in good agreement with field survey results. For the Baige barrier lake after the second landslide, the model predicts a flood peak discharge of about 2.5×10⁴ m³/s, an exposed population of about 2.5×10³ persons, a life loss of 2 persons, and a comprehensive score of 17.5 (high risk level), which is highly consistent with the official inverted discharge and actual zero casualties. The five-module rapid assessment model for barrier lake outburst risk established in this paper can quickly output quantifiable risk levels in emergency scenarios with limited information and tight time, providing a feasible quantitative tool for real-time interpretation, emergency command and risk zoning of barrier lake disasters.