Journal Articles

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915

Browse

Has files: YesSubject: search.filters.subject.Emergency management

Search Results

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item
    Tsunami evacuation modelling via micro-simulation model
    (Elsevier B.V., 2023-02-15) Fathianpour A; Evans B; Jelodar MB; Wilkinson S
    The associated tsunami risks posed to coastal regions in earthquake-prone areas highlight the importance of an effective emergency evacuation plan for these regions. Evacuation simulations have shown to be a valuable tool in assessing the effectiveness of existing evacuation plans and providing solutions for risk reduction, and improving community readiness. This paper describes the development of a micro-simulation evacuation model (MSEM) to assess the effectiveness of local tsunami evacuation processes and test the results with a velocity-based theoretical model. As an agent-based model, the MSEM considers both pedestrian and vehicle interactions and their interactions with each other. The models were used to assess the evacuation scenarios for a tsunami-prone city Napier, in New Zealand. The evacuation process was evaluated based on a local 8.4 Mw earthquake that would trigger a tsunami event, with an evacuation time of 50 min between feeling the initial shake in Napier City and the time of arrival of the tsunami wave. The study outlined within this paper assumes two scenarios: (1) effected population would evacuate by foot, and (2) affected population would evacuate by car, considered to take place during the afternoon at the traffic peak time. The results of the MSEM show factors such as evacuation method, lane and sidewalk capacities, and interactions between individuals affect the individuals' ability to safely evacuate. The MSEM model based on scenario 1 and 2 for Napier City, demonstrated around 85% of residents would reach designated safe area when all evacuating by foot, whilst, only 45% of evacuees will reach their designated safe zone if all individuals attempted to use vehicles as their means of evacuation.
  • Thumbnail Image
    Item
    Environmental factors in tsunami evacuation simulation: topography, traffic jam, human behaviour
    (Springer Nature, 2024-06-07) Fathianpour A; Evans B; Babaeian Jelodar M; Wilkinson S
    The risk a tsunami, a high-rise wave, poses to coastal cities has been highlighted in recent years. Emergency management agencies have become more prepared, and new policies and strategies are in place to strengthen the city's resiliency to such events. Evacuation is a highly effective response to tsunamis, and recent models and simulations have provided valuable insights into mass evacuation scenarios. However, the accuracy of these simulations can be improved by accounting for additional environmental factors that affect the impact of a tsunami event. To this end, this study has been conducted to enhance an evacuation simulation model by considering topography that impacts traffic mobility and speed, traffic congestion, and human behaviour. The updated model was employed to evaluate the effectiveness of Napier City's current evacuation plan, as it can realistically simulate both pedestrian and vehicular traffic movements simultaneously. The simulation demonstrated in this paper was based on a scenario involving an 8.4 Mw earthquake from the Hikurangi subduction interface, which would trigger a tsunami risk in the area. Based on this event, the final evacuation time (time between after the shake is felt and the arrival of the tsunami wave at the shoreline of Napier City) is considered to be 50 min. The results of the MSEM model are presented within two categories, (1) survival rate and (2) safe zone capacity. The evacuation simulation model used to examine the environmental factors in this study is the Micro-Simulation Evacuation Model (MSEM), an agent-based model capable of considering both pedestrian and vehicular interactions. The results showed that the steep pathway to the safe zone would markedly decrease the moving speed and reduce the survival rate, highlighting the need to have supporting vertical evacuation to reduce the number of evacuees heading to steep routes. Additionally, the modelling and assessment of mass evacuation by vehicles has highlighted regions of severe congestion due to insufficient network capacity. Through highlighting such regions, the model aid policy makers with a more targeted approach to infrastructure investment to improve flows of traffic in mass evacuation scenarios and increase survival rates.
  • Thumbnail Image
    Item
    Creating a ‘planning emergency levels of service’ framework – a silver bullet, or something useful for target practice?
    (Elsevier B.V., 2023-06-01) Mowll R; Becker J; Wotherspoon L; Stewart C; Johnston D; Neely D
    ‘Planning Emergency Levels of Service’ (PELOS) are service delivery goals for infrastructure providers during and after an emergency event. These goals could be delivered through the existing infrastructure (e.g., pipes, lines, cables), or through other means (trucked water or the provision of generators). This paper describes how an operationalised framework of PELOS for the Wellington region, New Zealand was created, alongside the key stakeholders. We undertook interviews and workshops with critical infrastructure entities to create the framework. Through this process we found five themes that informed the context and development of the PELOS framework: interdependencies between critical infrastructure, the need to consider the vulnerabilities of some community members, emergency planning considerations, stakeholders’ willingness to collaborate on this research/project and the flexibility/adaptability of the delivery of infrastructure services following a major event. These themes are all explored in this paper. This research finds that the understanding of the hazardscape and potential outages from hazards is critical and that co-ordination between key stakeholders is essential to create such a framework. This paper may be used to inform the production of PELOS frameworks in other localities.
  • Thumbnail Image
    Item
    A new mapping tool to visualise critical infrastructure levels of service following a major earthquake
    (Elsevier B.V., 2024-01) Mowll R; Anderson MJ; Logan TM; Becker JS; Wotherspoon LM; Stewart C; Johnston D; Neely D
    How can emergency management teams communicate to potentially impacted communities what a major event causing infrastructure outages might mean for them, and what they can do to prepare? In this paper we describe the process of creating a webtool for end users to visualise infrastructure outages that the Wellington region of New Zealand would face following a rupture of the Wellington fault. This webtool creates insight for three key groups: critical infrastructure owners, communities, and the emergency management sector itself. Critical infrastructure entities can use the tool to understand where they might consider infrastructure upgrades to mitigate gaps of delivery following a fault rupture, and to consider their emergency response plans for delivery in an emergency (leading to their consideration of ‘planning emergency levels of service’). Communities can use the tool to understand what infrastructure outages will mean at the household level in an emergency, including the considerable distances that some community members will have to walk to access services such as food and water and prepare for prolonged outages. Finally, with a greater knowledge of the gaps in delivery and of those community members that might need assistance with food and water collection, the emergency management sector can be better prepared. The methodology for creating the webtool is described, along with the insights that the completed webtool provides for emergency planning.
  • Thumbnail Image
    Item
    Modelling spatial population exposure and evacuation clearance time for the Auckland Volcanic Field, New Zealand
    (Elsevier BV, 2021-08) Wild AJ; Bebbington MS; Lindsay JM; Charlton DH
    Auckland, New Zealand's largest city (population of ~1.6 million), is situated atop the monogenetic Auckland Volcanic Field (AVF). As in many places faced with volcanic activity, evacuation is seen as the best risk mitigation strategy for preserving lives in the event of volcanic unrest and/or an eruption. However, planning for an evacuation can be challenging. In particular, the uncertainty in vent location resulting from the monogenetic nature of the field makes identifying neighbourhoods to be evacuated impractical until well into the pre-eruption unrest period. This study uses spatial analysis methods to assess exposure for both population and private transport ownership as well as to identify those areas requiring public transport support for an evacuation. These data were overlaid on a range of possible vent locations across the AVF using a 500 × 500 m grid. At each possible vent location, a 5 km evacuation zone is modelled, following the official contingency plan for evacuation in a future AVF event. In order to simulate vent location uncertainty leading up to a future eruption, a range of buffer distances were applied around the modelled vent locations. The exposure data derived were then used to model evacuation clearance time, which considered four phases: 1) the time taken to decide to call an evacuation; 2) the public notification time; 3) the evacuee's time to prepare; and 4) evacuee's travel time to beyond the evacuation zone. The length of time involved in phases 1 to 3 are all independent of the vent location; our analysis found these phases could be completed within 36 h, with over 80% confidence. Travel times to beyond the evacuation zone were modelled using the exposure analysis for population and private transport ownership combined with road network data and vehicle carrying capacity. This revealed travel times for this phase ranging from less than 1 up to 11 h, depending on traffic congestion, when considering no vent uncertainty. By combining the times modelled for all four phases, we found that when there is high certainty in the vent location, the median total evacuation clearance time with no congestion is approximately 37 h. However, include a 10 km vent uncertainty buffer into the model, the evacuation clearance time can increase to between 38 and 55 h, dependent on traffic congestion. A vent in the densely populated inner Auckland and CBD area would result in the greatest population required to evacuate, and also the greatest need for public transport support given the low vehicle ownership in this area. Our results can be used to inform emergency management decision making, and the model can be adapted for other regions as well as for other hazards.
  • Thumbnail Image
    Item
    A modular framework for the development of multi-hazard, multi-phase volcanic eruption scenario suites
    (Elsevier BV, 2022-07) Weir AM; Mead S; Bebbington MS; Wilson TM; Beaven S; Gordon T; Campbell-Smart C
    Understanding future volcanic eruptions and their potential impact is a critical component of disaster risk reduction, and necessitates the production of salient, robust hazard information for decision-makers and end-users. Volcanic eruptions are inherently multi-phase, multi-hazard events, and the uncertainty and complexity surrounding potential future hazard behaviour is exceedingly hard to communicate to decision-makers. Volcanic eruption scenarios are recognised to be an effective knowledge-sharing mechanism between scientists and practitioners, and recent hybrid scenario suites partially address the limitations surrounding the traditional deterministic scenario approach. Despite advances in scenario suite development, there is still a gap in the international knowledge base concerning the synthesis of multi-phase, multi-hazard volcano science and end-user needs. In this study we present a new modular framework for the development of complex, long-duration, multi-phase, multi-hazard volcanic eruption scenario suites. The framework was developed in collaboration with volcanic risk management agencies and researchers in Aotearoa-New Zealand, and is applied to Taranaki Mounga volcano, an area of high volcanic risk. This collaborative process aimed to meet end-user requirements, as well as the need for scientific rigour. This new scenario framework development process could be applied at other volcanic settings to produce robust, credible and relevant scenario suites that are demonstrative of the complex, varying-duration and multi-hazard nature of volcanic eruptions. In addressing this gap, the value of volcanic scenario development is enhanced by advancing multi-hazard assessment capabilities and cross-sector collaboration between scientists and practitioners for disaster risk reduction planning.