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Start date: 2021Subject: search.filters.subject.Risk assessment

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    Upscaling effects on infectious disease emergence risk emphasize the need for local planning in primary prevention within biodiversity hotspots
    (Springer Nature Limited, 2025-10-27) Muylaert RL; Wilkinson DA; Dwiyanti EI; Hayman DTS
    Zoonotic risk assessments are increasingly vital in the wake of recent epidemics. The microbial diversity of parasitic organisms correlates with host species richness, with regions of high biodiversity facing elevated risks of emerging zoonotic infections. While habitat loss and fragmentation reduce species diversity, anthropogenic encroachment, particularly in forested areas, amplifies human exposure to novel pathogens. This study integrates host habitat, biodiversity, human encroachment, and population at risk to estimate novel disease emergence and epidemic risk at multiple spatial scales. Using Java, Indonesia, as a case study, we demonstrate that degrading spatial resolution leads to information loss, with optimal resolutions typically below 2000 m, ideally around 500 m when native-resolution processing is unfeasible. Gravity models of epidemic spread highlight Jakarta and West Java as high-risk areas, with varying contributions from surrounding regions. Our spatial analysis underscores the influence of population centers on forest management and agroforestry practices. These findings offer valuable insights for guiding pandemic prevention research and improving pathogen- and driver-based risk monitoring strategies.
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    Rapid remote volcanic ashfall impact assessment for the 2022 eruption of Hunga volcano, Tonga: a bespoke approach and lessons identified
    (Springer Nature, 2024-10-28) Weir AM; Williams JH; Wilson TM; Hayes JL; Stewart C; Leonard GS; Magill C; Jenkins SF; Williams S; Craig HM; Kula T; Fraser S; Pomonis A; Gunasekera R; Daniell JE; Coultas E
    When disasters occur, rapid impact assessments are required to prioritise response actions, support in-country efforts and inform the mobilisation of aid. The 15 January 2022 eruption of Hunga volcano, Tonga, and the resulting atmospheric shockwave, ashfall, underwater mass disturbance and tsunami, caused substantial impacts across the Kingdom of Tonga. Volcanic impacts on the scale observed after the eruption are rare, necessitating a reliance on international advice and assistance. The situation was complicated by the loss of Tonga’s international submarine fibreoptic cable (causing a complete loss of communications for approximately 20 days) along with border closures due to the COVID-19 pandemic. A need emerged for a rapid remote volcanic impact assessment and provision of specialist advice to help inform the response of international partners. Here we present a novel methodology for conducting rapid remote volcanic ashfall impact assessments, conducted over a 10-day period following the eruption. We used three different hazard models for ashfall thickness across the main island of Tongatapu and available asset information and vulnerability functions for buildings, agriculture, electricity networks, water supply and roads, to provide initial estimates of losses due to ashfall from the 15 January eruption. For buildings, we estimated losses both as total losses and as percentages of the total replacement cost of buildings on Tongatapu. For agriculture, we made probabilistic estimates of production losses for three different crop classes. For ashfall clean-up, we estimated ranges of ashfall volumes requiring clean-up from road surfaces and roofs. For water supply, electricity networks and roads, our analysis was limited to assessing the exposure of important assets to ashfall, as we had insufficient information on system configurations to take the analysis further. Key constraints on our analysis were the limited nature of critical infrastructure asset inventories and the lack of volcanic vulnerability models for tropical regions including Pacific Island nations. Key steps towards iteratively improving rapid remote impact assessments will include developing vulnerability functions for tropical environments as well as ground-truthing estimated losses from remote approaches against in-person impact assessment campaigns.
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    A temporal network analysis of risk factors for suicide : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Clinical Psychology at Massey University, Manawatū, New Zealand
    (Massey University, 2024-03-19) Holman, Mikayla
    Suicide is a major public health concern in New Zealand, with the number of lives lost due to suicide increasing almost every year. The factors influencing a person’s decision to take their own life are numerous and often complex. Some of these factors are dynamic, fluctuating over short periods of time and ultimately altering a person’s risk for suicide. Network analysis is a novel statistical technique that can be used to explore complex causal associations in systems of variables, such as risk factors for suicide. The present study used temporal network analysis to explore the associations between dynamic risk factors for suicide over time. Data collection involved ecological momentary assessment, where a general community sample of 39 adult participants completed a brief survey five times per day for ten days, resulting in 1420 completed surveys. Each survey assessed participants’ momentary experience of suicidal ideation, depressed mood, hopelessness, social support, self-esteem, thwarted belongingness, perceived burdensomeness, anhedonia, worthlessness, alcohol intoxication, and fatigue. All variables fluctuated from measurement to measurement at least some of the time, highlighting the dynamic nature of suicide risk. Temporal, contemporaneous, and between-persons networks of the 11 measured variables were estimated using temporal network analysis. In the temporal network, hopelessness was the only variable that predicted an increase in suicidal ideation at the subsequent measurement. Multiple nodes were estimated to be positively associated with suicidal ideation in the contemporaneous network, including depressed mood, thwarted belongingness, perceived burdensomeness, and worthlessness, while self-esteem was negatively associated with suicidal ideation in this network. In the between-persons network, hopelessness was the only variable with a significant association with suicidal ideation. The results of this study highlight the importance of continuously assessing changes in suicide risk factors given their dynamic nature. Hopelessness may be an especially important risk factor to assess given its temporal association with increased suicidal ideation. Regarding future research opportunities, experimental N=1 network studies about the effectiveness of personalised interventions based on node centrality are an important next step in determining whether individualised networks have a place in personalised treatment for suicidality.
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    Contributions to food safety acceptance sampling plans : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Statistics, Massey University, School of Mathematical and Computer Sciences
    (Massey University, 2023) Thevaraja, Mayooran
    An appropriate sampling inspection method is an essential tool for risk assessment in the food industry. A representative sampling approach will be helpful to reduce risk while minimising the sampling costs. Consequently, food manufacturers are employing efficient sampling approaches to assure food safety. In the food safety field, microbiological or other contamination often spreads unevenly across the production. Many factors are involved in the microbial risk assessment, such as (1) the amount of sample used for inspection, (2) what sampling methods were applied, (3) laboratory testing procedures, (4) physical sampling of materials from lots/batches of products and (5) the mixing of initially collected samples. This study focusses on improved sampling inspection approaches to reduce microbiological risk in food products. Part of this research also included developing open-source R packages to generate graphical displays for probabilistic risk assessment for practitioners. A single “wrapper” package is also provided to install all the newly developed packages in a single step.
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    How risk informs natural hazard management : a study of the interface between risk modelling for tsunami inundation and local government policies and procedures : a thesis presented for the degree of Doctor of Philosophy in Emergency Management, Massey University, Wellington, New Zealand
    (Massey University, 2021) Crawford, Miles
    The impact of natural hazards on society and the environment continues to increase, resulting in intolerable and unsustainable financial and social costs. The traditional approach of responding to the hazard once it has occurred is no longer acceptable because it hasn’t always raised awareness of the hazard or allowed communities to pre-emptively take action to protect themselves and their property. It is now more important than ever for governments and communities to proactively understand and prepare for natural hazard risks before hazards occur, so that our vulnerability and exposure to them is reduced when they occur. The costs-benefits of following a proactive approach, rather than a reactive approach are clear, bringing about a change in the way natural hazards are managed, as exemplified by the risk management focus of the Sendai Framework for Disaster Risk Reduction (2015). Despite considerable research and effort in this area, natural hazard risk management struggles to be applied at global, national, and local scales. This illustrates a need to better understand how natural hazard risk is perceived and understood, and how it influences the development of policy frameworks for natural hazard management. In particular, questions remain regarding how risk modelling influences perception of natural hazard risk and application of risk reduction measures at the community level. This research explores how risk informs natural hazard management in Aotearoa New Zealand’s local government. It focusses on how the RiskScape risk modelling tool is used to communicate natural hazard risk for influencing risk awareness and the perceptions of practitioners. It specifically focusses on a tsunami hazard generated in the Hikurangi Subduction Margin as tsunami is Aotearoa New Zealand’s least likely but most significant natural hazard risk. However due to its infrequent occurrence, tsunami is perceived as less risky than other hazards. Focus group sessions and semi-structured qualitative interviews were held with natural hazard risk practitioners within local government, primarily across the Gisborne, Hawke’s Bay, and Wellington regions of Aotearoa New Zealand. The focus groups and interviews explored practitioners’ perceptions on the value of risk modelling tools, particularly ‘RiskScape', for communicating risk and influencing policy development, as well as their thoughts and opinions on natural hazard risk management policy development in general, and with a specific focus on tsunami. These results were then corroborated through document analysis of risk-based tsunami policy and procedure for the regions studied. This research found that while practitioners understand the value of risk modelling for communicating tsunami risk for developing risk awareness and influencing perceptions, RiskScape is not employed widely within local government to achieve risk-based policy and practice. This is partly attributed to trust in risk modelling outputs as well as developmental problems with the RiskScape software. However, the larger part is due to challenges for natural hazard risk management within local government. Local Government’s challenges include lack of guidance, mandate, and collaboration for hazard management; limited risk leadership, understanding and awareness; lack of funding, capacity, and capability; and unavailability of quality data. Underlying each of these challenges are more fundamental challenges relating to the disconnect of the ‘science-policy-practice’ interface, and the interrelated complexity of the challenges which limit the effectiveness of solutions. Along with the limited use of risk modelling, risk-based policy and procedure for tsunami remains scarce. Of the 58 national and local policy documents analysed as part of this research, only three contain specific tsunami risk-based policy. This research proposes the use of ‘systems thinking’ to better understand this complex system of challenges as a whole. This approach can identify intervention points, which can interrupt the system’s dynamics and better apply natural hazard risk management in local government. The science-policy-practice interface is identified as an intervention point; however, tensions for collaboration across this interface limit its effectiveness. A formalised structure, which is mandated by integrative research frameworks, is recommended for how collaboration across the science-policy-practice interface can be improved. An improved science-policy-practice interface would enable the application of further recommendations for overcoming challenges for local government natural hazard risk management. These include developing awareness of natural hazard risk and the cognitive biases that influence risk perceptions; improved understanding of the value in using established risk management approaches; and greater capacity and capability for collecting, managing, and using natural hazard risk data. The outcome would enable bottom-up, co-development of risk modelling, which is trusted and used within local government to better develop risk-based policy and procedure. Through greater use of risk modelling in local government, tsunami risk can be better communicated, and risk-based tsunami policy and procedure can be better achieved. This will reduce tsunami-related losses and enable greater community resilience.