考虑超标准洪水作用的沥青心墙坝溃决生命损失评估模型

Assessment model of life loss due to asphalt core wall dam breach considering effect of super-standard flood

抗冲刷能力更强的沥青心墙坝一旦遭遇超标准洪水,将面临溃决风险,对下游人民造成严重威胁。现有针对沥青心墙坝的溃决生命损失研究尚属匮乏,亟需开展生命损失评估。本文分析超标准洪水作用下沥青心墙坝的溃决特征,考虑生命损失影响因素之间的相互作用过程,基于溃决洪水致灾机制构建生命损失定量评估模型,实现溃决生命损失的快速定量分析;通过方法对比和敏感性分析,明晰不同影响因素对溃决生命损失的作用规律。将模型应用于新疆射月沟溃决案例发现:溃决洪峰流量为3320 m^(3)/s,溃决历时3.35 h,与实际结果相符;生命损失定量模型分析结果为31人,与实际误差在11%以内,优于其他损失模型;风险人口的敏感性指数I_(max)和I_(min)值最大,分别为1.436、0.486,是射月沟溃决生命损失最重要的影响因素,其他依次为洪水严重性、是否撤离、警报时间、淹没范围。

Once an asphalt core wall dam with strong anti-scour capability encounters a super-standard flood,it will be faced with the risk of collapse and pose a grave threat to downstream people.Previous studies on life loss caused by asphalt core wall dam breach are still lacking,and its assessment is an urgent issue.This paper presents an analysis of the characteristics of the breach flood under the action of a super-standard flood.Considering the interaction between the influencing factors of life loss,we construct a physical model for a quantitative assessment,based on the disaster-causing mechanism of breach flood,so as to realize a rapid quantitative analysis of life loss.Through method comparison and sensitivity analysis,the roles of different life loss factors are determined.This model is applied in a case study of the Sheyuegou breach in Xinjiang.We find the breach flood features a peak flow of 3320 m^(3)/s and a duration of 3.35 h,which agrees with the real conditions.The quantitative life loss model predicts 31 casualties and its error is within 11%,better than previous life loss models.The sensitivity indexes I_(max) and I_(min) of the at-risk population are the largest,1.44 and 0.19,respectively.They are the two most important factors of life loss caused by the Sheyuegou dam breach.Other factors are the severity of flood,whether to evacuate,alarm timing,and inundation extent.