城市洪涝中人体失稳机理与判别标准研究进展

受全球气候变化和人类活动影响,近年来极端降水事件增多,由此引发的城市洪涝灾害频发。行人在洪水作用下易失去稳定,威胁生命安全,研究洪水中人体的失稳机理与判别标准,能为城市洪涝灾害的风险评估与管理提供科学依据。本文首先总结了国内外城市洪涝中人体失稳机理研究的相关成果,评估了现有人体失稳判别标准的适用范围及优缺点。基于力学分析和实测数据率定的计算公式虽然在推导过程中有一定的简化,但能较好地反映洪水中人体失稳的动力学机理,可以评估不同人群与不同洪水条件下的人体稳定性。针对当前城市洪涝中人体稳定性研究存在的不足,需要开展真实洪水中行人逃生以及沿漫水楼梯行走时的失稳机理与判别标准研究,并深入研究行人站立姿势调整对洪水中人体稳定性的影响;还需基于大数据等手段获取互联网上洪水中人体失稳的影像资料,构建洪水中人体失稳的实测数据库;同时还需推动人体失稳判别标准在洪水风险管理中的具体应用,最大程度地降低城市洪涝灾害带来的不利影响。

Review on instability mechanisms and criteria of human body in floodwaters

Because of global climate change and human activities, the occurrence frequency of extreme precipitation events is increasing steadily, which causes devastating flood disasters. The stability of a human body can be compromised when exposed to floodwaters, which definitely threatens the life of a human being. Therefore, the investigation into mechanisms and criteria of human instability in floodwaters can provide scientific bases for urban flood risk assessments and hazard reduction measures, and can also benefit the ability of emergency response. This paper summarizes existing studies on instability mechanisms and criteria for people in floodwaters. Based on the summarization, the application scope, advantages and disadvantages of these existing criteria for human instability are evaluated in detail. Even though the calibrated formulas based on mechanical analysis and measured data involve some simplifications, they can reflect the critical mechanical condition of human instability in floodwaters, and therefore show better universality in practice. Given the limitations and shortcomings of the existing studies as well as major threats in current urban flood disasters, this study also presents key future research directions, including the instability mechanisms and criteria of pedestrian evacuation in actual flood conditions and from flooded stairs;using big data technologies to obtain and analyze online resources of flood instability videos and images, and reasonably estimate the critical instability state to construct a dataset of body instability in floodwaters;conduct in-depth studies on the influence of body posture adjustment on flood hazard degree. Besides, it is necessary to promote the application of human instability criteria in the field of urban flooding disaster prevention and reduction, in order to minimize the disadvantageous impacts of urban flood disasters.