基于公平性的灾前多目标公交疏散模型

Pre-disaster Multiple Objectives Bus Evacuation Model Based on Equity

面对洪涝、海啸等重大可预测性自然灾害的发生,高效的灾前疏散可以减少人员伤亡。针对当前疏散行动片面关注效率而忽略公平这一问题,采用相对剥夺成本衡量集结点之间获得疏散服务的公平程度,以驾驶时间、相对剥夺成本和公交数量最小化为目标,将集结点时间窗、公交载客量等作为约束,构建多目标公交疏散路径优化模型以协同优化疏散效率和公平;模型采用NSGA-Ⅱ算法求解。算例结果表明,疏散时效与公平、疏散时效与所用公交数量之间存在悖反关系,疏散公平与所用公交数量呈正相关;与仅考虑疏散时效的单目标模型对比,兼顾疏散效率与公平的疏散方案能在略微降低疏散时效和略微提高所用公交数量的基础上,显著降低疏散的不公平程度。结果有助于为实际疏散行动提供有效参考。

Efficient pre-disaster evacuation can reduce casualties when facing the major and predictable natural disasters such as floods and tsunamis.In view of the problem that evacuation activities focus on efficiency but ignore equity,the relative deprivation cost is used to measure the equity of access to evacuation service between assembly points,taking the minimum driving time,the relative deprivation cost and the number of used buses as the objectives,and the time window of assembly points and bus capacity as constraints,the paper constructs a multi-objective bus evacuation route optimization model to simultaneously optimize evacuation efficiency and equity.The model is solved by NSGA-Ⅱalgorithm.Results show that evacuation timeliness and equity have an inverse relationship,evacuation timeliness and the number of used buses have an inverse relationship,and equity is positively correlated with the number of used buses.Compared with the single objective model that only considers evacuation timeliness,the evacuation scheme that considers evacuation efficiency and equity can significantly decreases the evacuation inequity on the basis of slightly reducing evacuation timeliness and slightly increasing the number of used buses.Results can provide effective reference for practical evacuation.