暴雨内涝情景下城市道路交通网络脆弱性研究

Research on the vulnerability of urban road traffic networks under rainstorm and waterlogging scenarios

为研究暴雨内涝对城市道路交通网络脆弱性的影响机理,耦合MIKE 21水动力模型与城市道路交通网络级联失效模型,重现暴雨情境下城市道路交通网络失效过程,以郑州市中心城区为研究区域,分析在不同重现期下的积水范围分布特征以及受内涝影响的城市道路交通网络脆弱性变化情况。结果显示:在4种设计暴雨情境下,积水淹没范围主要集中在城区的东北部;随着设计重现期的增加,较深积水区间道路数量占比显著增加,旅行时间加权网络效率明显降低。当暴雨重现期从50 a增加到100 a时,受影响路段数量以及级联失效路段比例数增加最多。研究能够为城市洪涝应急管理工作与韧性城市的建设提供理论依据。

To comprehensively and effectively evaluate the vulnerability of urban road traffic networks during rainstorm and waterlogging disasters,the failure process of the urban road traffic network under rainstorm conditions was reenacted by integrating the MIKE 21 hydrodynamic model with the cascade failure model of the urban road traffic network.The structural vulnerability and operating state vulnerability of the urban road network are comprehensively assessed by considering both the topological structure characteristics and traffic carrying capacity characteristics.Finally,the study focuses on the central urban area of Zhengzhou,where a rainstorm waterlogging numerical model is developed to analyze the distribution characteristics of water accumulation during different recurrence periods.This model deeply examines the changes in vulnerability of the urban road traffic network under the influence of waterlogging.According to the findings,in the four designed rainstorm scenarios,the area with water depths exceeding 30 cm showed a clear distribution trend of“less in the southwest and more in the northeast”within the inundation zone.The northeastern area of the central city of Zhengzhou was the primary concentration point for the inundation area,with some scattered,less concentrated areas in other parts.The distribution of impacted sections within the road traffic network mirrors that of the inundated areas,and the spatial distribution of vulnerability levels closely correlates with the spatial distribution of water depth.This correlation sheds light on the changes in vulnerability of the urban road traffic network under rainstorm conditions.Additionally,as the design recurrence period increased,there was a significant increase in the number of roads within the deep water area,coupled with a notable decrease in travel time weighted network efficiency.Specifically,as the rainstorm recurrence period extended from 50 years to 100 years,there was a particularly significant increase in the number of affected sections and the proportion of cascaded failure sections.This underscores the serious adverse impact that rainstorm-induced waterlogging can have on urban transportation systems.