The supply of water following disasters has always been of significant concern to communities. Failure of water systems not only causes difficulties for residents and critical users but may also affect other hard and soft infrastructure and services. The dependency of communities and other infrastructure on the availability of safe and reliable water places even more emphasis on the resilience of water supply systems. This thesis makes two major contributions. First, it proposes a framework for measuring the multifaceted resilience of water systems, focusing on the significance of the characteristics of different communities for the resilience of water supply systems. The proposed framework, known as the CARE framework, consists of eight principal activities: (1) developing a conceptual framework; (2) selecting appropriate indicators; (3) refining the indicators based on data availability; (4) correlation analysis; (5) scaling the indicators; (6) weighting the variables; (7) measuring the indicators; and (8) aggregating the indicators. This framework allows researchers to develop appropriate indicators in each dimension of resilience (i.e., technical, organisational, social, and economic), and enables decision makers to more easily participate in the process and follow the procedure for composite indicator development. Second, it identifies the significant technical, social, organisational and economic factors, and the relevant indicators for measuring these factors. The factors and indicators were gathered through a comprehensive literature review. They were then verified and ranked through a series of interviews with water supply and resilience specialists, social scientists and economists. Vulnerability, redundancy and criticality were identified as the most significant technical factors affecting water supply system robustness, and consequently resilience. These factors were tested for a scenario earthquake of Mw 7.6 in Pukerua Bay in New Zealand. Four social factors and seven indicators were identified in this study. The social factors are individual demands and capacities, individual involvement in the community, violence level in the community, and trust. The indicators are the Giving Index, homicide rate, assault rate, inverse trust in army, inverse trust in police, mean years of school, and perception of crime. These indicators were tested in Chile and New Zealand, which experienced earthquakes in 2010 and 2011 respectively. The social factors were also tested in Vanuatu following TC Pam, which hit the country in March 2015. Interestingly, the organisational dimension contributed the largest number of factors and indicators for measuring water supply resilience to disasters. The study identified six organisational factors and 17 indicators that can affect water supply resilience to disasters. The factors are: disaster precaution; predisaster planning; data availability, data accessibility and information sharing; staff, parts, and equipment availability; pre-disaster maintenance; and governance. The identified factors and their indicators were tested for the case of Christchurch, New Zealand, to understand how organisational capacity affected water supply resilience following the earthquake in February 2011. Governance and availability of critical staff following the earthquake were the strongest organisational factors for the Christchurch City Council, while the lack of early warning systems and emergency response planning were identified as areas that needed to be addressed. Economic capacity and quick access to finance were found to be the main economic factors influencing the resilience of water systems. Quick access to finance is most important in the early stages following a disaster for response and restoration, but its importance declines over time. In contrast, the economic capacity of the disaster struck area and the water sector play a vital role in the subsequent reconstruction phase rather than in the response and restoration period. Indicators for these factors were tested for the case of the February 2011 earthquake in Christchurch, New Zealand. Finally, a new approach to measuring water supply resilience is proposed. This approach measures the resilience of the water supply system based on actual water demand following an earthquake. The demand-based method calculates resilience based on the difference between water demand and system capacity by measuring actual water shortage (i.e., the difference between water availability and demand) following an earthquake.
Landslides are significant hazards, especially in seismically-active mountainous regions, where shaking amplified by steep topography can result in widespread landsliding. These landslides present not only an acute hazard, but a chronic hazard that can last years-to-decades after the initial earthquake, causing recurring impacts. The Mw 7.8 Kaikōura earthquake caused more than 20,000 landslides throughout North Canterbury and resulted in significant damage to nationally significant infrastructure in the coastal transport corridor (CTC), isolating Kaikōura from the rest of New Zealand. In the years following, ongoing landsliding triggered by intense rainfall exacerbated the impacts and slowed the recovery process. However, while there is significant research on co-seismic landslides and their initial impacts in New Zealand, little research has explored the evolution of co-seismic landslides and how this hazard changes over time. This research maps landslides annually between 2013 and 2021 to evaluate the changes in pre-earthquake, co-seismic and post-earthquake rates of landsliding to determine how landslide hazard has changed over this time. In particular, the research explores how the number, area, and spatial distribution of landslides has changed since the earthquake, and whether post-earthquake mitigation works have in any way affected the long-term landslide hazard. Mapping of landslides was undertaken using open-source, medium resolution Landsat-8 and Sentinel-2 satellite imagery, with landslides identified visually and mapped as single polygons that capture both the source zone and deposit. Three study areas with differing levels of post-earthquake mitigation are compared: (i) the northern CTC, where the majority of mitigation was in the form of active debris removal; (ii) the southern CTC, where mitigation was primarily via passive protection measures; and (iii) Mount Fyffe, which has had no mitigation works since the earthquake. The results show that despite similar initial impacts during the earthquake, the rate of recovery in terms of landslide rates varies substantially across the three study areas. In Mount Fyffe, the number and area of landslides could take 45 and 22 years from 2021 respectively to return to pre-earthquake levels at the current rate. Comparatively, in the CTC, it could take just 5 years and 3-4 years from 2021 respectively. Notably, the fastest recovery in terms of landslide rates in the CTC was primarily located directly along the transport network, whereas what little recovery did occur in Mount Fyffe appeared to follow no particular pattern. Importantly, recovery rates in the northern CTC were notably higher than in the southern CTC, despite greater co-seismic impacts in the former. Combined, these results suggest the active, debris removal mitigation undertaken in the northern CTC may have had the effect of dramatically reducing the time for landslide rates to return to pre-earthquake levels. The role of slope angle and slope aspect were explored to evaluate if these observations could be driven by local differences in topography. The Mount Fyffe study area has higher slope angles than the CTC as a whole and landslides predominantly occurred on slightly steeper slopes than in the CTC. This may have contributed to the longer recovery times for landsliding in Mount Fyffe due to greater gravitational instability, however the observed variations are minor compared to the differences in recovery rates. In terms of slope aspect, landslides in Mount Fyffe preferentially occurred on north- and south-facing slopes whereas landslides in the CTC preferred the east- and south-facing slopes. The potential role of these differences in landslide recovery remains unclear but may be related to the propagation direction of the earthquake and the tracking direction of post-earthquake ex-tropical cyclones. Finally, landslides in the CTC are observed to be moving further away from the transport network and the number of landslides impacting the CTC decreased significantly since the earthquake. Nevertheless, the potential for further landslide reactivation remains. Therefore, despite the recovery in the CTC, it is clear that there is still risk of the transport network being impacted by further landsliding, at least for the next 3-5 yrs.
Effective management of waste and debris generated by a disaster event is vital to ensure rapid and efficient response and recovery that supports disaster risk reduction (DRR). Disaster waste refers to any stream of debris that is created from a natural disaster that impacts the environment, infrastructure, and property. This waste can be problematic due to extensive volumes, environmental contamination and pollution, public health risks, and the disruption of response and recovery efforts. Due to the complexities in dealing with these diverse and voluminous materials, having disaster waste management (DWM) planning in place pre-event is crucial. In particular, coordinated, interagency plans that have been informed by estimates of waste volumes and types are vital to ensure management facilities, personnel, and recovery resources do not become overwhelmed. Globally, a priority when formulating DWM plans is the robust estimation of disaster waste stream types and volumes. This is a relatively under-researched area, despite the growing risk of natural disasters and increasingly inadequate waste management facilities. In Aotearoa New Zealand, a nation-wide DWM planning tool has been proposed for local government use, and waste amounts from events such as the Christchurch Earthquakes have been estimated. However, there has been little work undertaken to estimate waste types and volumes with a region-specific, multi-hazard focus, which is required to facilitate detailed regional DWM planning. This research provides estimates of potential disaster waste volumes and types in the Waitaha-Canterbury region of the South Island (Te Waipounamu) for three key hazard scenarios: a M8.0 Alpine Fault earthquake with a south-to-north rupture pattern, a far-sourced tsunami using a maximum credible event model for a Peru-sourced event, and major flooding using geospatial datasets taken from available local government modelling. Conducted in partnership with Environment Canterbury and Canterbury CDEM, this estimation work informed stakeholder engagement through multi-agency workshops at the district level. This research was comprised of two key parts. The first was enhancing and extending a disaster waste estimation model used in Wellington and applying it to the Canterbury region to quantify waste volumes and types. The second part was using this model and its estimates to inform engagement with stakeholders in multi-agency, district-level workshops in Kaikōura, Hurunui, and Waimakariri. In these workshops, the waste estimates were used to catalyse discussion around potential issues associated with the management of disaster waste. Regionally, model estimates showed that the earthquake scenario would generate the highest total volume of disaster waste (1.94 million m³), compared to the tsunami scenario (1.89 million m³) and the flood scenario (173,900 m³). Flood waste estimates are likely underrepresented due to limited flood modelling coverage, but still provide a valuable comparison. Whilst waste estimates differ significantly between districts, waste volumes were shown to be not solely dependent on building/population density. The district-level workshops showed that DWM challenges revolved around logistical constraints, public concerns, governance complexities, and environmental issues. Future work should further enhance this estimation model and apply it to other regions of Aotearoa New Zealand, to help develop a set of cohesive DWM plans for each region. The waste estimation model could also be adapted and applied internationally. The findings from this research provide a foundation for advancing DWM planning and stakeholder engagement in the Waitaha-Canterbury region. By offering region-specific waste estimates across multiple hazard scenarios, this work supports district councils and emergency managers in developing informed, proactive strategies for disaster preparedness and response. The insights gained from district-level workshops highlight key challenges that must be addressed in future planning. These outcomes contribute to a broader research agenda for DWM in Aotearoa New Zealand, and offer a framework adaptable to international contexts.
Recent surface-rupturing earthquakes in New Zealand have highlighted significant exposure and vulnerability of the road network to fault displacement. Understanding fault displacement hazard and its impact on roads is crucial for mitigating risks and enhancing resilience. There is a need for regional-scale assessments of fault displacement to identify vulnerable areas within the road network for the purposes of planning and prioritising site-specific investigations. This thesis employs updated analysis of data from three historical surface-rupturing earthquakes (Edgecumbe 1987, Darfield 2010, and Kaikoūra 2016) to develop an empirical model that addresses the gap in regional fault displacement hazard analysis. The findings contribute to understanding of • How to use seismic hazard model inputs for regional fault displacement hazard analysis • How faulting type and sediment cover affects the magnitude and spatial distribution of fault displacement • How the distribution of displacement and regional fault displacement hazard is impacted by secondary faulting • The inherent uncertainties and limitations associated with employing an empirical approach at a regional scale • Which sections of New Zealand’s roading network are most susceptible to fault displacement hazard and warrant site-specific investigations • Which regions should prioritise updating emergency management plans to account for post-event disruptions to roading. I used displacement data from the aforementioned historical ruptures to generate displacement versus distance-to-fault curves for various displacement components, fault types, and geological characteristics. Using those relationships and established relationships for along-strike displacement, displacement contours were generated surrounding active faults within the NZ Community Fault Model. Next, I calculated a new measure of 1D strain along roads as well as relative hazard, which integrated 1D strain and normalised slip rate data. Summing these values at the regional level identified areas of heightened relative hazard across New Zealand, and permits an assessment of the susceptibility of road networks using geomorphon land classes as proxies for vulnerability. The results reveal that fault-parallel displacements tend to localise near the fault plane, while vertical and fault-perpendicular displacements sustain over extended distances. Notably, no significant disparities were observed in off-fault displacement between the hanging wall and footwall sides of the fault, or among different surface geology types, potentially attributed to dataset biases. The presence of secondary faulting in the dataset contributes to increased levels of tectonic displacement farther from the fault, highlighting its significance in hazard assessments. Furthermore, fault displacement contours delineate broader zones around dip-slip faults compared to strike-slip faults, with correlations identified between fault length and displacement width. Road ‘strain’ values are higher around dip-slip faults, with notable examples observed in the Westland and Buller Districts. As expected, relative hazard analysis revealed elevated values along faults with high slip rates, notably along the Alpine Fault. A regional-scale analysis of hazard and exposure reveals heightened relative hazard in specific regions, including Wellington, Southern Hawke’s Bay, Central Bay of Plenty, Central West Coast, inland Canterbury, and the Wairau Valley of Marlborough. Notably, the Central West Coast exhibits the highest summed relative hazard value, attributed to the fast-slipping Alpine Fault. The South Island generally experiences greater relative hazard due to larger and faster-slipping faults compared to the North Island, despite having fewer roads. Central regions of New Zealand face heightened risk compared to Southern or Northern regions. Critical road links intersecting high-slipping faults, such as State Highways 6, 73, 1, and 2, necessitate prioritisation for site-specific assessments, emergency management planning and targeted mitigation strategies. Roads intersecting with the Alpine Fault are prone to large parallel displacements, requiring post-quake repair efforts. Mitigation strategies include future road avoidance of nearby faults, modification of road fill and surface material, and acknowledgement of inherent risk, leading to prioritised repair efforts of critical roads post-quake. Implementing these strategies enhances emergency response efforts by improving accessibility to isolated regions following a major surface-rupturing event, facilitating faster supply delivery and evacuation assistance. This thesis contributes to the advancement of understanding fault displacement hazard by introducing a novel regional, empirical approach. The methods and findings highlight the importance of further developing such analyses and extending them to other critical infrastructure types exposed to fault displacement hazard in New Zealand. Enhancing our comprehension of the risks associated with fault displacement hazard offers valuable insights into various mitigation strategies for roading infrastructure and informs emergency response planning, thereby enhancing both national and global infrastructure resilience against geological hazards.
Recent seismic events, such as the 2010-2011 Canterbury earthquakes and the 2016 Kaikōura earthquakes, have shed light on issues with the seismic performance of glazing systems. This is attributed to the limited amount of research and consideration of glazing systems in design and assessments. Previous research and evidence from post-earthquake reconnaissance have shown that glazing systems pose a hazard due to falling glass. As such, it is vital to ensure that glazing systems are designed with the necessary levels of seismic performance. Furthermore, the post-earthquake repair of glass facades can be costly and time-consuming. Some previous research has been conducted to highlight the seismic performance and fragility of glazing systems. However, most prior research only focussed on life-safety issues of glazing systems and rarely on the serviceability of glazing systems. The serviceability of glazing systems, such as water-tightness, is a vital aspect of glazing systems as a low serviceability capacity will increase the likelihood of further damage which will increase economic losses. This is the aim of this research, to provide insight towards the seismic performance of glazing systems considering both the serviceability and ultimate limit state by generating insight into the behaviour of glazing systems and developing tools for the consideration of glazing systems in design and assessment. This will allow a value proposition for seismic detailing of glazing to be evaluated. In order to provide insight into the behaviour of glazing systems and a means for evaluating their seismic performance, this research firstly develops an applicable experimental testing procedure that allows for serviceability limit state tests on glazing units. This experimental testing procedure is used to obtain data on the vulnerability of general New Zealand glazing systems’ performance, specifically unitised glazing systems that are commonly used as commercial shopfront glazing system types. These glazing systems typically realised using aluminium framing with gaskets connecting the frame to the glass. After the experimental testing, numerical analyses calibrated to the experimental testing results are conducted to enable robust analyses of glazing systems’ fragility. Finally, a value proposition for glazing systems with seismic detailing is made by comparing the performance of glazing systems with seismic detailing and conventional glazing systems. This comparison is done using the PEER-PBEE method and the economic implications of each glazing system is shown. Suggestions for designers and stakeholders aimed at reducing costs related to the seismic performance of glazing systems is also shown. Using the novel experimental method developed in this research, three different full-scale glazing systems were tested. A total of 10 unitised glazing specimens were tested; three with standard detailing, three with seismic detailing and four that were structurally glazed. These tests evaluated three damage states (DS): loss of water-tightness (DS1), gasket damage (DS2), and glass or framing failure (DS3). The experimental method that was adopted is considered to be more desirable than the optional procedures set out in New Zealand glazing standards. The method does not require high-speed testing equipment and is easy to replicate by the industry. The test results show that water-tightness was lost at low drift levels, with the first leakage occurring at just 0.15% drift for one specimen, while a standard glazing system had a median drift capacity of 0.35%. In contrast, seismic glazing systems detailed to better accommodate in-plane movements, demonstrated a significantly higher median drift capacity of 1.88%. The numerical approach proposed in this research has shown that it is possible to numerically model the glazing-gasket interaction to conservatively predict the water-leakage drift (damage state 1). The modelling approach still needs further development if it were to be used for damage states DS2 and DS3. The last part of the research considered the value proposition for seismic glazing systems. This was achieved by applying the FEMA P-58 performance assessment framework to a number of case study buldings that are typical of New Zealand design. The results suggest that it may not be economically worthwhile to use well-detailed seismic glazing systems despite the considerably larger drift capacity they possess relative to standard systems. However, as the cost of seismic glazing systems reduces, and more information on repair costs for different damage states is obtained, the value proposition may change.
Recognising that informal (also termed family, whānau, aiga or unpaid) caregivers/carers are a vital part of Aotearoa New Zealand’s health system, providing care and support for loved ones, whānau, friends and neighbours, this study aimed to explore the experiences of older informal caregivers during the COVID-19 pandemic. Priority research questions were: how did informal caregivers experience caregiving during the pandemic, and how might we support them during another pandemic, disaster, or national emergency? To our knowledge, this is the first exploration of such experiences in Aotearoa New Zealand. We wanted to understand the unprecedented challenges and barriers informal caregivers faced during the pandemic and highlight the resilience and mana (power, strength) of informal caregivers in overcoming them. To explore the lived experiences of informal caregiving during the pandemic, the research team travelled across New Zealand between May 2023 and February 2024 to conduct 81 in-depth interviews, with 73 completed face-to-face, four via Zoom and four by phone. A total of 34 male and 47 female informal caregivers were interviewed, including 35 Māori and 46 non-Māori. The mean age of participants was 66 years old. Thirty-nine rural and 42 urban-dwelling informal caregivers were interviewed, and the study covered both the North and South Islands. A Kaupapa Māori researcher and a Māori adviser oversaw appropriate tikanga (processes), kōrero (discussion) and manaakitanga (care and support) for all the Māori participants interviewed. The COVID-19 pandemic placed significant strain on older informal caregivers in Aotearoa New Zealand, exacerbating existing challenges and exposing critical gaps in support systems. Many participants experienced heightened emotional and psychological distress due to increased caregiving demands, social isolation, and the disruption of formal and informal support networks. The closure of essential services meant that informal caregivers in this study had to navigate complex healthcare systems with little guidance, often facing bureaucratic hurdles and limited access to respite care. Financial strain further compounded these difficulties, with some participants struggling to meet the rising costs associated with informal caregiving while experiencing reduced income or employment instability. For Māori participants, the inability to engage in kanohi ki te kanohi (face-to-face) interactions with whānau and communities disrupted cultural traditions such as whanaungatanga, tangihanga (funeral practices), and communal caregiving, intensifying feelings of isolation and distress. Despite these challenges, participants demonstrated remarkable resilience and adaptability, drawing on their life experiences (or "resilience in older people") and existing support systems to navigate the pandemic. Many participants relied on self-sufficiency, using strategies learned from past crises and disasters such as the 2010-2011 Canterbury earthquakes and the 1940s/1950s polio epidemics to manage caregiving responsibilities and everyday challenges with limited external assistance. Strengthened relationships with care recipients and an increased sense of community support were positive outcomes for some participants, who found solace in tighter family bonds and mutual aid from neighbours and local groups. Māori participants, in particular, emphasised the importance of cultural and community-based networks, with iwi and extended whānau playing crucial roles in providing informal support. These findings underscore the need for policies that recognise and support the diverse needs of informal caregivers, including tailored caregiving assistance, clearer communication about available services, and culturally responsive caregiving frameworks that strengthen resilience in future health crises. Findings from this study highlight the need for: 1) tailored, context-specific support systems: Formal support services must be more flexible to accommodate the diverse needs of informal caregivers, particularly those in rural and Māori communities; 2) Improved access to information and services: Many participants were unaware of available support, pointing to the need for clearer, caregiver-specific communication and helplines; 3) Enhancing emotional and social support mechanisms: Regular check-ins from healthcare providers and community groups could alleviate the emotional burden of caregiving; and 4) Resilience-based and bicultural approaches to caregiving support: Policies should integrate Māori perspectives on informal caregiving and strengthen social capital among informal caregivers. It is clear from this research that no one-size-fits-all approach is appropriate for supporting informal caregivers. This research provides a critical evidence base for improving the support structures available to informal caregivers, ensuring they are better prepared for future pandemics, disasters, and national emergencies.
The Eastern Humps and Leader faults, situated in the Mount Stewart Range in North Canterbury, are two of the ≥17 faults which ruptured during the 2016 MW7.8 Kaikōura Earthquake. The earthquake produced complex, intersecting ground ruptures of these faults and the co-seismic uplift of the Mount Stewart Range. This thesis aims to determine how these two faults accommodated deformation during the 2016 earthquake and how they interact with each other and with pre-existing geological structures. In addition, it aims to establish the most likely subsurface geometry of the fault complex across the Mount Stewart Range, and to investigate the paleoseismic history of the Leader Fault. The Eastern Humps Fault strikes ~240° and dips 80° to 60° to the northwest and accommodated right- lateral – reverse-slip, with up to 4 m horizontal and 2 m vertical displacement in the 2016 earthquake. The strike of the Leader Fault varies from ~155 to ~300°, and dips ~30 to ~80° to the west/northwest, and mainly accommodated left-lateral – reverse-slip of up to 3.5 m horizontal and 3.5 m vertical slip in the 2016 earthquake. On both the Eastern Humps and Leader faults the slip is variable along strike, with areas of low total displacement and areas where horizontal and vertical displacement are negatively correlated. Fault traces with low total displacement reflect the presence of off-fault (distributed) displacement which is not being captured with field measurements. The negative correlation of horizontal and vertical displacement likely indicates a degree of slip partitioning during the 2016 earthquake on both the Eastern Humps and Leader faults. The Eastern Humps and Leader faults have a complex, interdependent relationship with the local bedrock geology. The Humps Fault appears to be a primary driver of ongoing folding and deformation of the local Mendip Syncline and folding of the Mount Stewart Range, which probably began prior to, or synchronous with, initial rupture of The Humps Fault. The Leader Fault appears to use existing lithological weaknesses in the Cretaceous-Cenozoic bedrock stratigraphy to rupture to the surface. This largely accounts for the strong variability on the strike and dip of the Leader Fault, as the geometry of the surface ruptures tend to reflect the strike and dip of the geological strata which it is rupturing through. The Leader Fault may also accommodate some degree of flexural slip in the Cenozoic cover sequence of the Mendip Syncline, contributing to the ongoing growth of the fold. The similarity between topography and uplift profiles from the 2016 earthquake suggest that growth of the Mount Stewart Range has been primarily driven by multiple (>500) discrete earthquakes that rupture The Humps and Leader faults. The spatial distribution of surface displacements across the Mount Stewart Range is more symmetrical than would be expected if uplift is driven primarily by The Humps and Leader faults alone. Elastic dislocation forward models were used to model potential sub-surface geometries and the resulting patterns of deformation compared to photogrammetry-derived surface displacements. Results show a slight preference for models with a steeply southeast-dipping blind fault, coincident with a zone of seismicity at depth, as a ‘backthrust’ to The Humps and Leader faults. This inferred Mount Stewart Fault accommodated contractional strain during the 2016 earthquake and contributes to the ongoing uplift of the Mount Stewart Range with a component of folding. Right-lateral and reverse shear stress change on the Hope Fault was also modelled using Coulomb 3.3 software to examine whether slip on The Humps and Leader faults could transfer enough stress onto the Hope Fault to trigger through-going rupture. Results indicate that during the 2016 earthquake right-lateral shear and reverse stress only increased on the Hope Fault in small areas to the west of the Leader Fault, and similar ruptures would be unlikely to trigger eastward propagating rupture unless the Hope Fault was close to failure prior to the earthquake. Paleoseismic trenches were excavated on the Leader Fault at four locations from 2018 to 2020, revealing near surface (< 4m depth) contractional deformation of Holocene stratigraphy. Three of the trench locations uncovered clear evidence for rupture of the Leader Fault prior to 2016, with fault displacement of near surface stratigraphy being greater than displacement recorded during the 2016 earthquake. Radiocarbon dating of in-situ organic material from two trenches indicate a date of the penultimate earthquake on the Leader Fault within the past 1000 years. This date is consistent with The Humps and Leader faults having ruptured simultaneously in the past, and with multi-fault ruptures involving The Humps, Leader, Hundalee and Stone Jug faults having occurred prior to the 2016 Kaikōura earthquake. Overall, the results contribute to an improved understanding of the Kaikōura earthquake and highlight the importance of detailed structural and paleoseismic investigations in determining controls on earthquake ‘complexity’.
The recent instances of seismic activity in Canterbury (2010/11) and Kaikōura (2016) in New Zealand have exposed an unexpected level of damage to non-structural components, such as buried pipelines and building envelope systems. The cost of broken buried infrastructure, such as pipeline systems, to the Christchurch Council was excessive, as was the cost of repairing building envelopes to building owners in both Christchurch and Wellington (due to the Kaikōura earthquake), which indicates there are problems with compliance pathways for both of these systems. Councils rely on product testing and robust engineering design practices to provide compliance certification on the suitability of product systems, while asset and building owners rely on the compliance as proof of an acceptable design. In addition, forensic engineers and lifeline analysts rely on the same product testing and design techniques to analyse earthquake-related failures or predict future outcomes pre-earthquake, respectively. The aim of this research was to record the actual field-observed damage from the Canterbury and Kaikōura earthquakes of seismic damage to buried pipeline and building envelope systems, develop suitable testing protocols to be able to test the systems’ seismic resilience, and produce prediction design tools that deliver results that reflect the collected field observations with better accuracy than the present tools used by forensic engineers and lifeline analysts. The main research chapters of this thesis comprise of four publications that describe the gathering of seismic damage to pipes (Publication 1 of 4) and building envelopes (Publication 2 of 4). Experimental testing and the development of prediction design tools for both systems are described in Publications 3 and 4. The field observation (discussed in Publication 1 of 4) revealed that segmented pipe joints, such as those used in thick-walled PVC pipes, were particularly unsatisfactory with respect to the joint’s seismic resilience capabilities. Once the joint was damaged, silt and other deleterious material were able to penetrate the pipeline, causing blockages and the shutdown of key infrastructure services. At present, the governing Standards for PVC pipes are AS/NZS 1477 (pressure systems) and AS/NZS 1260 (gravity systems), which do not include a protocol for evaluating the PVC pipes for joint seismic resilience. Testing methodologies were designed to test a PVC pipe joint under various different simultaneously applied axial and transverse loads (discussed in Publication 3 of 4). The goal of the laboratory experiment was to establish an easy to apply testing protocol that could fill the void in the mentioned standards and produce boundary data that could be used to develop a design tool that could predict the observed failures given site-specific conditions surrounding the pipe. A tremendous amount of building envelope glazing system damage was recorded in the CBDs of both Christchurch and Wellington, which included gasket dislodgement, cracked glazing, and dislodged glazing. The observational research (Publication 2 of 4) concluded that the glazing systems were a good indication of building envelope damage as the glazing had consistent breaking characteristics, like a ballistic fuse used in forensic blast analysis. The compliance testing protocol recognised in the New Zealand Building Code, Verification Method E2/VM1, relies on the testing method from the Standard AS/NZS 4284 and stipulates the inclusion of typical penetrations, such as glazing systems, to be included in the test specimen. Some of the building envelope systems that failed in the recent New Zealand earthquakes were assessed with glazing systems using either the AS/NZS 4284 or E2/VM1 methods and still failed unexpectedly, which suggests that improvements to the testing protocols are required. An experiment was designed to mimic the observed earthquake damage using bi-directional loading (discussed in Publication 4 of 4) and to identify improvements to the current testing protocol. In a similar way to pipes, the observational and test data was then used to develop a design prediction tool. For both pipes (Publication 3 of 4) and glazing systems (Publication 4 of 4), experimentation suggests that modifying the existing testing Standards would yield more realistic earthquake damage results. The research indicates that including a specific joint testing regime for pipes and positioning the glazing system in a specific location in the specimen would improve the relevant Standards with respect to seismic resilience of these systems. Improving seismic resilience in pipe joints and glazing systems would improve existing Council compliance pathways, which would potentially reduce the liability of damage claims against the government after an earthquake event. The developed design prediction tool, for both pipe and glazing systems, uses local data specific to the system being scrutinised, such as local geology, dimensional characteristics of the system, actual or predicted peak ground accelerations (both vertically and horizontally) and results of product-specific bi-directional testing. The design prediction tools would improve the accuracy of existing techniques used by forensic engineers examining the cause of failure after an earthquake and for lifeline analysts examining predictive earthquake damage scenarios.
This thesis describes the management process of innovation through construction infrastructure projects. This research focuses on the innovation management process at the project level from four views. These are categorised into the separate yet related areas of: “innovation definition”, “Project time”, “project team motivation” and “Project temporary organisation”. A practical knowledge is developed for each of these research areas that enables project practitioners to make the best decision for the right type of innovation at the right phase of projects, through a capable project organisation. The research developed a holistic view on both innovation and the construction infrastructure project as two complex phenomena. An infrastructure project is a long-term capital investment, highly risky and an uncertain. Infrastructure projects can play a key role in innovation and performance improvement throughout the construction industry. The delivery of an infrastructure project is affected in most cases by critical issues of budget constraint, programme delays and safety Where the business climate is characterized by uncertainty, risk and a high level of technological change, construction infrastructure projects are unable to cope with the requirement to develop innovation. Innovation in infrastructure projects, as one of the key performance indicators (KPI) has been identified as a critical capability for performance improvement through the industry. However, in spite of the importance of infrastructure projects in improving innovation, there are a few research efforts that have developed a comprehensive view on the project context and its drivers and inhibitors for innovation in the construction industry. Two main reasons are given as the inhibitors through the process of comprehensive research on innovation management in construction. The first reason is the absence of an understanding of innovation itself. The second is a bias towards research at a firm and individual level, so a comprehensive assessment of project-related factors and their effects on innovation in infrastructure projects has not been undertaken. This study overcomes these issues by adopting as a case study approach of a successful infrastructure project. This research examines more than 500 construction innovations generated by a unique infrastructure alliance. SCIRT (Stronger Christchurch Infrastructure Rebuild Team) is a temporary alliancing organisation that was created to rebuild and recover the damaged infrastructure after the Christchurch 2011 earthquake. Researchers were given full access to the innovation project information and innovation systems under a contract with SCIRT Learning Legacy, provided the research with material which is critical for understanding innovations in large, complex alliancing infrastructure organisation. In this research, an innovation classification model was first constructed. Clear definitions have been developed for six types of construction innovation with a variety of level of novelties and benefits. The innovation classification model was applied on the SCIRT innovation database and the resultant trends and behaviours of different types of innovation are presented. The trends and behaviours through different types of SCIRT innovations developed a unique opportunity to research the projectrelated factors and their effect on the behaviour of different classified types of innovation throughout the project’s lifecycle. The result was the identification of specific characteristics of an infrastructure project that affect the innovation management process at the project level. These were categorised in four separate chapters. The first study presents the relationship between six classified types of innovation, the level of novelty and the benefit they come up with, by applying the innovation classification model on SCIRT innovation database. The second study focused on the innovation potential and limitations in different project lifecycle phases by using a logic relationship between the six classified types of innovation and the three classified phases of the SCIRT project. The third study result develops a holistic view of different elements of the SCIRT motivation system and results in a relationship between the maturity level of definition developed for innovation as one of the KPIs and a desire though the SCIRT innovation incentive system to motivate more important innovations throughout the project. The fourth study is about the role of the project’s temporary organisation that finally results in a multiple-view innovation model being developed for project organisation capability assessment in the construction industry. The result of this thesis provides practical and instrumental knowledge to be used by a project practitioner. Benefits of the current thesis could be categorized in four groups. The first group is the innovation classification model that provides a clear definition for six classified types of innovation with four levels of novelty and specifically defined outcomes and the relationship between the innovation types, novelty and benefit. The second is the ability that is provided for the project practitioner to make the best decision for the right type of innovation at the right phases of a project’s lifecycle. The third is an optimisation that is applied on the SCIRT innovation motivation system that enables the project practitioner to incentivize the right type of innovation with the right level of financial gain. This drives the project teams to develop a more important innovation instead of a simple problemsolving one. Finally, the last and probably more important benefit is the recommended multiple-view innovation model. This is a tool that could be used by a project practitioner in order to empower the project team to support innovation throughout the project.
A review of the literature showed the lack of a truly effective damage avoidance solution for timber or hybrid timber moment resisting frames (MRFs). Full system damage avoidance selfcentring behaviour is difficult to achieve with existing systems due to damage to the floor slab caused by beam-elongation. A novel gravity rocking, self-centring beam-column joint with inherent and supplemental friction energy dissipation is proposed for low-medium rise buildings in all seismic zones where earthquake actions are greater than wind. Steel columns and timber beams are used in the hybrid MRF such that both the beam and column are continuous thus avoiding beam-elongation altogether. Corbels on the columns support the beams and generate resistance and self-centring through rocking under the influence of gravity. Supplemental friction sliders at the top of the beams resist sliding of the floor whilst dissipating energy as the floor lifts on the corbels and returns. 1:20 scale tests of 3-storey one-by-two bay building based on an earlier iteration of the proposed concept served as proof-of-concept and highlighted areas for improvement. A 1:5 scale 3-storey one-by-one bay building was subsequently designed. Sub-assembly tests of the beam-top asymmetric friction sliders demonstrated repeatable hysteresis. Quasi-static tests of the full building demonstrated a ‘flat bottomed’ flag-shaped hysteresis. Shake table tests to a suite of seven earthquakes scaled for Wellington with site soil type D to the serviceability limit state (SLS), ultimate limit state (ULS) and maximum credible event (MCE) intensity corresponding to an average return period of 25, 500 and 2500 years respectively were conducted. Additional earthquake records from the 22 February 2011 Christchurch earthquakes we included. A peak drift of 0.6%, 2.5% and 3.8% was reached for the worst SLS, ULS and MCE earthquake respectively whereas a peak drift of 4.5% was reached for the worst Christchurch record for tests in the plane of the MRF. Bi-directional tests were also conducted with the building oriented at 45 degrees on the shake table and the excitation factored by 1.41 to maintain the component in the direction of the MRF. Shear walls with friction slider hold-downs which reached similar drifts to the MRF were provided in the orthogonal direction. Similar peak drifts were reached by the MRF in the bi-directional tests, when the excitation was amplified as intended. The building self-centred with a maximum residual drift of 0.06% in the dynamic tests and demonstrated no significant damage. The member actions were magnified by up to 100% due to impact upon return of the floor after uplift when the peak drift reached 4.5%. Nonetheless, all of the members and connections remained essentially linearelastic. The shake table was able to produce a limited peak velocity of 0.275 m/s and this limited the severity of several of the ULS, MCE and Christchurch earthquakes, especially the near-field records with a large velocity pulse. The full earthquakes with uncapped velocity were simulated in a numerical model developed in SAP2000. The corbel supports were modelled with the friction isolator link element and the top sliders were modelled with a multi-linear plastic link element in parallel with a friction spring damper. The friction spring damper simulated the increase in resistance with increasing joint rotation and a near zero return stiffness, as exhibited by the 1:5 scale test building. A good match was achieved between the test quasi-static global force-displacement response and the numerical model, except a less flat unloading curve in the numerical model. The peak drift from the shake table tests also matched well. Simulations were also run for the full velocity earthquakes, including vertical ground acceleration and different floor imposed load scenarios. Excessive drift was predicted by the numerical model for the full velocity near-field earthquakes at the MCE intensity and a rubber stiffener for increasing the post joint-opening stiffness was found to limit the drift to 4.8%. Vertical ground acceleration had little effect on the global response. The system generates most of its lateral resistance from the floor weight, therefore increasing the floor imposed load increased the peak drift, but less than it would if the resistance of the system did not increase due to the additional floor load. A seismic design procedure was discussed under the framework of the existing direct displacement-based design method. An expression for calculating the area-based equivalent viscous damping (EVD) was derived and a conservative correction factor of 0.8 was suggested. A high EVD of up to about 15% can be achieved with the proposed system at high displacement ductility levels if the resistance of the top friction sliders is maximised without compromising reliable return of the floor after uplift. Uniform strength joints with an equal corbel length up the height of the building and similar inter-storey drifts result in minimal relative inter-floor uplift, except between the first floor and ground. Guidelines for detailing the joint for damage avoidance including bi-directional movement were also developed.
The research is funded by Callaghan Innovation (grant number MAIN1901/PROP-69059-FELLOW-MAIN) and the Ministry of Transport New Zealand in partnership with Mainfreight Limited. Need – The freight industry is facing challenges related to climate change, including natural hazards and carbon emissions. These challenges impact the efficiency of freight networks, increase costs, and negatively affect delivery times. To address these challenges, freight logistics modelling should consider multiple variables, such as natural hazards, sustainability, and emission reduction strategies. Freight operations are complex, involving various factors that contribute to randomness, such as the volume of freight being transported, the location of customers, and truck routes. Conventional methods have limitations in simulating a large number of variables. Hence, there is a need to develop a method that can incorporate multiple variables and support freight sustainable development. Method - A minimal viable model (MVM) method was proposed to elicit tacit information from industrial clients for building a minimally sufficient simulation model at the early modelling stages. The discrete-event simulation (DES) method was applied using Arena® software to create simulation models for the Auckland and Christchurch corridor, including regional pick-up and delivery (PUD) models, Christchurch city delivery models, and linehaul models. Stochastic variables in freight operations such as consignment attributes, customer locations, and truck routes were incorporated in the simulation. The geographic information system (GIS) software ArcGIS Pro® was used to identify and analyse industrial data. The results obtained from the GIS software were applied to create DES models. Life cycle assessment (LCA) models were developed for both diesel and battery electric (BE) trucks to compare their life cycle greenhouse gas (GHG) emissions and total cost of ownership (TCO) and support GHG emissions reduction. The line-haul model also included natural hazards in several scenarios, and the simulation was used to forecast the stock level of Auckland and Christchurch depots in response to each corresponding scenario. Results – DES is a powerful technique that can be employed to simulate and evaluate freight operations that exhibit high levels of variability, such as regional pickup and delivery (PUD) and linehaul. Through DES, it becomes possible to analyse multiple factors within freight operations, including transportation modes, routes, scheduling, and processing times, thereby offering valuable insights into the performance, efficiency, and reliability of the system. In addition, GIS is a useful tool for analysing and visualizing spatial data in freight operations. This is exemplified by their ability to simulate the travelling salesman problem (TSP) and conduct cluster analysis. Consequently, the integration of GIS into DES modelling is essential for improving the accuracy and reliability of freight operations analysis. The outcomes of the simulation were utilised to evaluate the ecological impact of freight transport by performing emission calculations and generating low-carbon scenarios to identify approaches for reducing the carbon footprint. LCA models were developed based on simulation results. Results showed that battery-electric trucks (BE) produced more greenhouse gas (GHG) emissions in the cradle phase due to battery manufacturing but substantially less GHG emissions in the use phase because of New Zealand's mostly renewable energy sources. While the transition to BE could significantly reduce emissions, the financial aspect is not compelling, as the total cost of ownership (TCO) for the BE truck was about the same for ten years, despite a higher capital investment for the BE. Moreover, external incentives are necessary to justify a shift to BE trucks. By using simulation methods, the effectiveness of response plans for natural hazards can be evaluated, and the system's vulnerabilities can be identified and mitigated to minimize the risk of disruption. Simulation models can also be utilized to simulate adaptation plans to enhance the system's resilience to natural disasters. Novel contributions – The study employed a combination of DES and GIS methods to incorporate a large number of stochastic variables and driver’s decisions into freight logistics modelling. Various realistic operational scenarios were simulated, including customer clustering and PUD truck allocation. This showed that complex pickup and delivery routes with high daily variability can be represented using a model of roads and intersections. Geographic regions of high customer density, along with high daily variability could be represented by a two-tier architecture. The method could also identify delivery runs for a whole city, which has potential usefulness in market expansion to new territories. In addition, a model was developed to address carbon emissions and total cost of ownership of battery electric trucks. This showed that the transition was not straightforward because the economics were not compelling, and that policy interventions – a variety were suggested - could be necessary to encourage the transition to decarbonised freight transport. A model was developed to represent the effect of natural disasters – such as earthquake and climate change – on road travel and detour times in the line haul freight context for New Zealand. From this it was possible to predict the effects on stock levels for a variety of disruption scenarios (ferry interruption, road detours). Results indicated that some centres rather than others may face higher pressure and longer-term disturbance after the disaster subsided. Remedies including coastal shipping were modelled and shown to have the potential to limit the adverse effects. A philosophical contribution was the development of a methodology to adapt the agile method into the modelling process. This has the potential to improve the clarification of client objectives and the validity of the resulting model.
According to TS 1170.5, designing a building to satisfy code-prescribed criteria (e.g., drift limit, member safety, P-Δ stability) at the ultimate limit state and relying on the inherent margins within the design code would lead to an acceptable mean annual frequency of collapse (λ꜀) in the range of 10−⁴ to 10−⁵. Modern performance objectives, such as λ꜀ and expected annual loss (EAL), are not explicitly considered. Although buckling-restrained braced frame (BRBF) buildings were widely adopted as lateral load-resisting systems for office and car park buildings in the Christchurch rebuild following the Canterbury earthquakes in New Zealand, there are currently no official guidelines for their design. The primary focus of this study is to develop a risk-targeted design framework for BRBF buildings that can achieve the performance objectives desired by stakeholders. To this extent, key factors influencing λ꜀ and EAL of BRBF buildings are identified. These factors include gusset plate design, number of storeys, design drift limit, BRBF beam-column connection, brace configuration, brace angle, brace material grade, and analysis method (equivalent lateral force vs. modal response spectrum). A novel 3D BRBF modelling approach capable of simulating out-of-plane buckling failure of buckling-restrained brace (BRB) gusset plates is developed. Prior experimental studies on sub-assemblies conducted elsewhere have demonstrated that gusset plates and end zones may buckle out of plane prematurely, before BRBs reach their maximum axial compression load carrying capacity. Current 2D BRBF macro models, typically used in research, cannot simulate this failure mode. A conventional 2D BRBF model underestimates the λ꜀ of a case-study 4-storey super-X configured steel BRBF building (designed according to NZS-3404) by a factor of two compared to the estimate from the proposed 3D model. These findings suggest that the current NZS-3404 gusset plate design method may undersize gusset plates and that using a 2D BRBF model in this case can significantly underestimate λ꜀. Three improved alternative gusset plate design methods that are easy to implement in practice are identified from the literature. Gusset plates in two case-study 4-storey steel BRBF buildings with super-X and diagonal configurations are designed using both the NZS-3404 method and alternative methods. All three alternative design methods are found to be conservative, resulting in an almost three-fold lower λ꜀ for both case-study BRBF buildings compared to those designed using the NZS-3404 method. Analysis results indicate that (i) bidirectional interaction has no significant effect on gusset plate buckling and (ii) mid-span gusset plates are more susceptible to buckling than corner gusset plates. A framework for seismic loss assessment using incremental dynamic analysis (IDA), called loss-oriented hazard-consistent incremental dynamic analysis (LOHC-IDA), is developed. IDA can be conducted with a generic record set, eliminating the arduous site-specific record selection required to conduct multiple stripe analysis (MSA). Traditional IDA, however, is limited in producing hazard-consistent estimates of engineering demand parameters (EDPs), which LOHC-IDA overcomes. LOHC-IDA improves upon existing methods by: (i) incorporating correlations among engineering demand parameters across intensity levels and (ii) using peak ground acceleration (PGA) to predict peak floor acceleration (PFA). For two case-study steel BRBF buildings, LOHC-IDA estimates the EAL and loss distributions conditioned on the intensity level that closely match the MSA results, with an average absolute error of 5%. The influence of factors beyond gusset plate design on the λ꜀ and EAL of 26 case-study steel BRBF buildings (designed in accordance with TS 1170.5) is examined. Hazard-consistent λ꜀ and EAL for these buildings are estimated using the FEMA P-58 loss and risk assessment framework. Among the 26 case-study buildings, 23 satisfy the maximum code-specified λ꜀ limit of 10−⁴. The EAL, normalised by the total building replacement cost, is highest for 2-storey BRBFs (0.22% on average), followed by 4-storey BRBFs (0.16% on average) and 8-storey BRBFs (0.11% on average). Reducing the design drift limit has the most significant effect on lowering λ꜀ (all BRBF designs were drift governed), followed by transitioning from pinned to moment-resisting beam-column connections, reducing the brace angle, and increasing brace strength. BRBF buildings designed using the equivalent lateral force method, on average, have a lower λ꜀ compared to those designed using the modal response spectrum method. Diagonally configured BRBFs exhibit the lowest λ꜀, followed by super- X and chevron configured BRBFs. Most design variables, apart from drift limit and beam-column connection, have limited influence on EAL. A simple method for EDP-targeted design of steel BRBF buildings is proposed. For this purpose, linear regression and CatBoost machine learning models are developed to predict steel BRBF building EDPs using peak storey drift ratio (PSDR) and PFA estimates from the 26 case-study buildings at intensity levels ranging from 80% to 0.5% probability of exceedance in 50 years. The R²ₐₔⱼ of these models is around 0.98, while the average prediction error is less than 10%. Fundamental period (T₁), total building height (Hₜ), and pseudospectral acceleration at T₁, denoted as Sₐ(T₁), are selected as the features to predict PSDR, while T₁, Hₜ, and PGA are the features selected to predict PFA. The EDP-targeted design has three steps: (i) for a given Hₜ value, the PSDR prediction model is used to identify a suitable T₁ that can achieve a desired PSDR target at the design intensity, (ii) a force-based design is then conducted iteratively to achieve the target T₁ by using an appropriate ductility factor and design drift limit, and (iii) based on the T₁ in the final design iteration, the PFA demand estimated by the PFA prediction models is used as a conservative input for the design of acceleration-sensitive non-structural elements. An equation to predict λ꜀ at the design stage is proposed for collapse risk-targeted seismic design of buildings. This equation comprises three principal components: reserve building strength, a proxy for effective structural stiffness, and reserve building deformation capacity. This equation is calibrated for the collapse risk-targeted design of BRBF buildings in New Zealand using results from 26 case-study BRBF buildings. The validity of this equation is demonstrated with three design verification examples designed to specific λ꜀ targets. Considering λ꜀ from hazard-consistent incremental dynamic analysis as the benchmark, the mean absolute percentage error in the design-stage prediction of λ꜀ of the verification buildings is approximately 10%.
Ongoing climate change triggers increasing temperature and more frequent extreme events which could limit optimal performance of haliotids, affect their physiology and biochemistry as well as influencing their population structure. Haliotids are a valuable nearshore fishery in a number of countries and many are showing a collapse of stocks because of overexploitation, environmental changes, loss of habitat, and disease. The haliotid in New Zealand commonly referred to as the blackfoot pāua (Haliotis iris) contribute a large and critical cultural, recreational and economic resource. Little was known about pāua responses to increasing temperature and acute environmental factors, as well as information about population size structure in Kaikoura after the earthquake 2016 and in Banks Peninsula. The aims of this study were to investigate the effects of temperature on scope for growth (SfG); physiological and biochemical responses of pāua subjected to different combined stressors including acute temperature, acute salinity and progressive hypoxia; and describe population size structure and shell morphology in different environments in Kaikoura and Banks Peninsula. The main findings of the present study found that population size structures of pāua were site-specific, and the shell length and shell height ratio of 3.25 could distinguish between stunted and non-stunted populations. The study found that high water temperature resulted in a reduction in absorbed energy from food, an increase in respiration energy, and ammonia excretion energy. Surveys were conducted at six study sites around the Canterbury Region over three years in order to better understand the population size structure and shell morphology of pāua. The findings found that the population size structure at 6 sites differed. Both juveniles and adults were found in intertidal areas at five sites. However, at Cape Three Points, pāua were found only in subtidal zones. One of the sites, Little Port Cooper, had a stunted population where only two pāua reached 125 mm in length over three years. In addition, most pāua in Little Port Cooper and Cape Three Points were adults, while Seal Reef had mostly juveniles. Wakatu Quay and Omihi had a full size range of pāua. Oaro population was dominated with juveniles and sub-adults. Recruitment and growth of pāua were successful after the earthquake in 2016. Research into pāua shell morphologies also determined that shell dimensions differed between sites. The relationships of shell length to shell width were linear and the relationship of shell length to shell height was curvilinear. Interestingly, SL:SH ratio of 3.25 is able to be used to identify stunted and non-stunted populations for pāua larger than 90 mm in length. Little Port Cooper was a stunted population with mean SL:SH ratio being 3.16. In the laboratory, scope for growth of pāua was investigated at four different temperatures of 12oC, 15oC, 18oC and 21oC over four weeks’ acclimation. The current study has found that SfG of pāua highly depended on temperature. Absorbed energy and respiration energy accounted for the highest proportion of the SfG of pāua. The respiration energy of pāua accounted for approximately 36%, 40%, 49% and 69% of the absorbed energy at 12°C, 15°C, 18°C and 21°C, respectively. The pāua at all acclimation temperatures had a positive scope for growth. The study suggested that the SfG was highest at 15°C, while the value at 21°C was the lowest. However, SfG at 18°C and 21°C decreased after 14 days of acclimation. Because of maintaining almost unchanged oxygen consumption over four weeks’ acclimation, pāua showed their poor abilities to acclimate to an increase in temperature. Therefore, they may be more vulnerable in future warming scenarios. The physiological and biochemical responses of pāua toward different combined stressors included three experiments. In terms of the acute temperature experiment, pāua were acclimated at 12oC, 15oC, 18oC or 21oC for two weeks before stepwise exposure to four temperatures of 12oC, 15oC, 18oC and 21oC every 4 hours. The acute salinity change, pāua were acclimated at 12oC, 15oC or 18oC over two weeks. Pāua were then exposed to a stepwise decrease of salinity of 2‰ every two hours from 34 – 22‰. Regarding the declining oxygen level, pāua were acclimated at 15 oC or 18oC for two weeks before exposure to one of four temperatures at 12oC, 15oC, 18oC or 21oC in one hour. After that acute progressive hypoxia was studied in closed respirometers for around six hours. The findings showed that there were interactions between combined stressors, affecting physiology of pāua (metabolism and heart rate). This suggests that environmental factors do not have a separate effect, but they also have interactions that enhance negative effects on pāua. Also, both oxygen uptake and heart rate responded quickly to temperature change and increased with rising temperature. On the other hand, oxygen uptake and heart rate decreased with reducing salinity and progressive hypoxia (before critical oxygen tension - Pcrit). Pcrit over four acute temperature exposures, ranged between 30.2 and 80.0 mmHg, depending on the exposure temperature. Acclimation temperature, combined with acute temperature, salinity or hypoxia stress affected the biochemistry of pāua. Pāua are osmoconformers so decreased salinity resulted in reducing haemolymph ionic concentration and increasing body volume. They were hypo-ionic with respect to sodium and potassium over the salinity ranges of 34 - 22‰. Haemocyanin accounts for a large pecentage of haemolymph protein, so trends of protein followed haemocyanin. Pāua tended to store oxygen in haemocyanin under extreme salinity stress at 22‰ and extreme hypoxia around 10 mmHg, rather than in oxygen transport. In conclusion, pāua at different sites had different population structures and morphologies. Pāua are sensitive to environmental stressors. They consumed more oxygen at high temperatures because they do not have thermal acclimation capacity. They are also osmoconformers with haemolymph sodium and potassium decreasing with salinity medium. Under progressive hypoxia, pāua could regulate oxygen and heart rate until Pcrit depending on temperature. Acute environmental changes also disturbed haemolyph parameters. 12°C and 15°C could be in the range of optimal temperature with higher SfG and less stress when exposed to acute environmental changes. Meanwhile long term exposure to 21°C is likely to be outside of the optimal range for the pāua. With ongoing climate change, pāua populations are more vulnerable so conservation is necessary. The research contributes to improving fishery management, providing insights into different environmental stressors affecting the energy demand and physiological and biochemical responses of pāua. It also allow to predicting the growth patterns and responses of pāua to adapt to climate change.
