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Hurricane evacuation: Origin, route, and destination.

机译:飓风疏散:出发地,路线和目的地。

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摘要

Recent natural disasters have highlighted the need to evacuate people as quickly as possible. During hurricane Rita in 2005, people were stuck in queue buildups and large scale congestions, due to improper use of capacity, planning and inadequate response to vehicle breakdown, flooding and accidents. Every minute is precious in situation of such disaster scenarios.;Understanding evacuation demand loading is an essential part of any evacuation planning. One of the factors often understood to effect evacuation, but not modeled has been the effect of a previous hurricane. This has also been termed as the 'Katrina Effect', where, due to the devastation caused by hurricane Katrina, large number of people decided to evacuate during Hurricane Rita, which hit Texas three weeks after Katrina hit Louisiana. An important aspect influencing the rate of evacuation loading is Evacuation Preparation Time also referred to as 'Mobilization time' in literature. A methodology to model the effect of a recent past hurricane on the mobilization times for evacuees in an evacuation has been presented utilizing simultaneous estimation techniques. The errors for the two simultaneously estimated models were significantly correlated, confirming the idea that a previous hurricane does significantly affect evacuation during a subsequent hurricane. The results show that the home ownership, number of individuals in the household, income levels, and level/risk of surge were significant in the model explaining the mobilization times for the households. Pet ownership and number of kids in the households, known to increase the mobilization times during isolated hurricanes, were not found to be significant in the model.;Evacuation operations are marred by unexpected blockages, breakdown of vehicles and sudden flooding of transportation infrastructure. A fast and accurate simulation model to incorporate flexibility into the evacuation planning procedure is required to react to such situations. Presently evacuation guidelines are prepared by the local emergency management, by testing various scenarios utilizing micro-simulation, which is extremely time consuming and do not provide flexibility to evacuation plans. To gain computational speed there is a need to move away from the level of detail of a micro-simulation to more aggregated simulation models. The Cell Transmission Model which is a mesoscopic simulation model is considered, and compared with VISSIM a microscopic simulation model. It was observed that the Cell Transmission Model was significantly faster compared to VISSIM, and was found to be accurate.;The Cell Transmission model has a nice linear structure, which is utilized to construct Linear Programming Problems to determine optimal strategies. Optimization models were developed to determine strategies for optimal scheduling of evacuation orders and optimal crossover locations for contraflow operations on freeways. A new strategy termed as 'Dynamic Crossovers Strategy' is proposed to alleviate congestion due to lane blockages (due to vehicle breakdowns, incidents etc.). This research finds that the strategy of implementing dynamic crossovers in the event of lane blockages does improve evacuation operations. The optimization model provides a framework within which optimal strategies are determined quickly, without the need to test multiple scenarios using simulation.;Destination networks are the cause of the main bottlenecks for evacuation routes, such aspects of transportation networks are rarely studied as part of evacuation operations. This research studies destination networks from a macroscopic perspective. Various relationships between network level macroscopic variables (Average Flow, Average Density and Average speed) over the network were studied. Utilizing these relationships, a "Network Breathing Strategy" was proposed to improve dissipation of evacuating traffic into the destination networks. The network breathing strategy is a cyclic process of allowing vehicles to enter the network till the network reaches congestion, which is followed by closure of their entry into the network until the network reaches an acceptable state. After which entrance into the network is allowed again. The intuitive motivation behind this methodology is to ensure that the network does not remain in congested conditions. The term 'Network Breathing' was coined due to the analogy seen between this strategy to the process of breathing, where vehicles are inhaled by the network (vehicles allowed in) and dissipated by the network (vehicles are not allowed in). It is shown that the network breathing improves the dissipation of vehicle into the destination network.;Evacuation operations can be divided into three main levels: at the origin (region at risk), routes and destination. This research encompasses all the three aspects and proposes a framework to assess the whole system in its entirety. At the Origin the demand dictates when to schedule evacuation orders, it also dictates the capacity required on different routes. These breakthroughs will provide a framework for a real time Decision Support System which will help emergency management official make decisions faster and on the fly.
机译:最近的自然灾害凸显了尽快撤离人员的必要性。在2005年的丽塔(Rita)飓风期间,由于容量使用不当,计划不足以及对车辆故障,洪水和事故的反应不足,人们陷入了排队等候和大规模拥堵的困境。在这种灾难情况下,每分钟都是宝贵的。了解疏散需求是任何疏散计划的重要组成部分。经常被理解为影响撤离的因素之一,但尚未建模,是先前飓风的影响。这也被称为“卡特里娜飓风效应”,由于卡特里娜飓风造成的破坏,许多人决定在卡特里娜飓风袭击路易斯安那州三周后袭击德克萨斯州的丽塔飓风期间撤离。影响疏散负荷率的一个重要方面是疏散准备时间,在文献中也称为“动员时间”。已经提出了一种利用同步估计技术来模拟最近发生的飓风对撤离人员疏散时间的影响的方法。这两个同时估计的模型的误差显着相关,从而确认了先前的飓风确实会严重影响随后的飓风疏散的想法。结果表明,在解释家庭动员时间的模型中,房屋所有权,家庭人数,收入水平以及激增水平/风险是重要的。在该模型中,没有发现宠物的所有权和家庭中孩子的数量会增加动员时间,众所周知,该模型中没有显着影响。疏散操作因意外的堵塞,车辆故障和交通基础设施的突然洪水而受到损害。为了对这种情况做出反应,需要一种快速,准确的仿真模型来将灵活性纳入疏散计划程序中。目前,疏散指南是由当地应急管理部门通过使用微观模拟测试各种场景来准备的,这非常耗时并且不能为疏散计划提供灵活性。为了提高计算速度,需要从微仿真的细节层次转移到更汇总的仿真模型。考虑了作为介观模拟模型的单元传输模型,并将其与VISSIM进行了比较以作为微观模拟模型。可以看到,与VISSIM相比,单元传输模型要快得多,并且被认为是准确的。单元传输模型具有良好的线性结构,可用于构造线性规划问题来确定最佳策略。开发了优化模型来确定针对高速公路上逆流操作的疏散命令的最佳调度和最佳交叉位置的策略。提出了一种称为“动态交叉策略”的新策略,以缓解由于车道阻塞(由于车辆故障,事故等)引起的拥堵。这项研究发现,在车道阻塞的情况下实施动态交叉的策略确实可以改善疏散操作。优化模型提供了一个框架,可在其中快速确定最佳策略,而无需使用仿真来测试多个场景。目的地网络是疏散路线主要瓶颈的原因,运输网络的这些方面很少作为疏散的一部分进行研究操作。这项研究从宏观的角度研究目标网络。研究了网络上网络级宏观变量(平均流量,平均密度和平均速度)之间的各种关系。利用这些关系,提出了“网络呼吸策略”,以改善将通信疏散到目标网络的耗散。网络呼吸策略是一个循环过程,允许车辆进入网络直到网络出现拥塞,然后关闭其进入网络的入口,直到网络达到可接受的状态。之后,再次允许进入网络。这种方法背后的直观动机是确保网络不会保持拥塞状态。之所以创造“网络呼吸”一词,是因为该策略与呼吸过程之间存在类比,在这种过程中,车辆被网络吸入(允许车辆进入)并被网络消散(不允许车辆进入)。结果表明,网络呼吸改善了车辆向目标网络的消散。疏散操作可以分为三个主要层次:在起点(危险区域),路线和目的地。这项研究涵盖了所有三个方面,并提出了一个评估整个系统整体的框架。在起点,需求决定了何时安排疏散命令,也决定了不同路线上所需的运力。这些突破将为实时决策支持系统提供框架,该系统将帮助应急管理人员更快,更快速地做出决策。

著录项

  • 作者

    Dixit, Vinayak V.;

  • 作者单位

    University of Central Florida.;

  • 授予单位 University of Central Florida.;
  • 学科 Engineering Civil.;Transportation.
  • 学位 Ph.D.
  • 年度 2008
  • 页码 168 p.
  • 总页数 168
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 建筑科学;综合运输;
  • 关键词

  • 入库时间 2022-08-17 11:39:17

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