Fine grained sediment deposition in urban environments during natural hazard events can impact critical infrastructure and properties (urban terrain) leading to reduced social and economic function and potentially adverse public health effects. Therefore, clean-up of the sediments is required to minimise impacts and restore social and economic functionality as soon as possible. The strategies employed to manage and coordinate the clean-up significantly influence the speed, cost and quality of the clean-up operation. Additionally, the physical properties of the fine grained sediment affects the clean-up, transport, storage and future usage of the sediment. The goals of the research are to assess the resources, time and cost required for fine grained sediment clean-up in an urban environment following a disaster and to determine how the geotechnical properties of sediment will affect urban clean-up strategies. The thesis focuses on the impact of fine grained sediment (<1 mm) deposition from three liquefaction events during the Canterbury earthquake sequence (2010-2011) on residential suburbs and transport networks in Christchurch. It also presents how geotechnical properties of the material may affect clean-up strategies and methods by presenting geotechnical analysis of tephra material from the North Island of New Zealand. Finally, lessons for disaster response planning and decision making for clean-up of sediment in urban environments are presented. A series of semi-structured interviews of key stakeholders supported by relevant academic literature and media reports were used to record the clean-up operation coordination and management and to make a preliminary qualification of the Christchurch liquefaction ejecta clean-up (costs breakdown, time, volume, resources, coordination, planning and priorities). Further analysis of the costs and resources involved for better accuracy was required and so the analysis of Christchurch City Council road management database (RAMM) was done. In order to make a transition from general fine sediment clean-up to specific types of fine disaster sediment clean-up, adequate information about the material properties is required as they will define how the material will be handled, transported and stored. Laboratory analysis of young volcanic tephra from the New Zealand’s North Island was performed to identify their geotechnical properties (density, granulometry, plasticity, composition and angle of repose). The major findings of this research were that emergency planning and the use of the coordinated incident management system (CIMS) system during the emergency were important to facilitate rapid clean-up tasking, management of resources and ultimately recovery from widespread and voluminous liquefaction ejecta deposition in eastern Christchurch. A total estimated cost of approximately $NZ 40 million was calculated for the Christchurch City clean-up following the 2010-2011 Canterbury earthquake sequence with a partial cost of $NZ 12 million for the Southern part of the city, where up to 33% (418 km) of the road network was impacted by liquefaction ejecta and required clearing of the material following the 22 February 2011 earthquake. Over 500,000 tonnes of ejecta has been stockpiled at Burwood landfill for all three liquefaction inducing earthquake events. The average cost per kilometre for the event clean-up was $NZ 5,500/km (4 September 2010), $NZ 11,650/km (22 February 2011) and $NZ 11,185/km (13 June 2011). The duration of clean-up time of residential properties and the road network was approximately two to three months for each of the three liquefaction ejecta events; despite events volumes and spatial distribution of ejecta. Interviews and quantitative analysis of RAMM data revealed that the experience and knowledge gained from the Darfield earthquake (4 September 2010) clean-up increased the efficiency of the following Christchurch earthquake induced liquefaction ejecta clean-up events. Density, particle size, particle shape, clay content and moisture content, are the important geotechnical properties that need to be considered when planning for a clean-up method that incorporates collection, transport and disposal or storage. The geotechnical properties for the tephra samples were analysed to increase preparedness and reaction response of potentially affected North Island cities from possible product from the active volcanoes in their region. The geotechnical results from this study show that volcanic tephra could be used in road or construction material but the properties would have to be further investigated for a New Zealand context. Using fresh volcanic material in road, building or flood control construction requires good understanding of the material properties and precaution during design and construction to extra care, but if well planned, it can be economically beneficial.
Disasters that significantly affect people typically result in the production of documents detailing disaster lessons. This was the case in the 2010 and 2011 Canterbury earthquakes, as government and emergency response agencies, community organisations, and the media, engaged in the practice of producing and reporting disaster lessons. This thesis examines the disaster lessons that were developed by emergent groups following the Canterbury earthquakes (4 September 2010 and 22 February 2011). It adopts a Foucauldian analysis approach to investigate both the construction of disaster lessons and to document how this practice has come to dominate postdisaster activity following the Canterbury earthquakes. The study involved an analysis of academic literature, public documents and websites and interviews with key members of a range of Canterbury based emergent community groups. This material was used to generate a genealogy of disaster lessons, which was given in order to generate an account of how disaster lessons emerged and have come to dominate as a practice of disaster management. The thesis then examines the genealogy through the concept of governmentality so as to demonstrate how this discourse of disaster lessons has come to be used as a governing rationale that shapes and guides the emergent groups conduct in postdisaster New Zealand.
The potential for a gastroenteritis outbreak in a post-earthquake environment may increase because of compromised infrastructure services, contaminated liquefaction (lateral spreading and surface ejecta), and the presence of gastroenteritis agents in the drinking water network. A population in a post-earthquake environment might be seriously affected by gastroenteritis because it has a short incubation period (about 10 hours). The potential for a gastroenteritis outbreak in a post-earthquake environment may increase because of compromised infrastructure services, contaminated liquefaction (lateral spreading and surface ejecta), and the presence of gastroenteritis agents in the drinking water network. A population in a post-earthquake environment might be seriously affected by gastroenteritis because it has a short incubation period (about 10 hours). The aim of this multidisciplinary research was to retrospectively analyse the gastroenteritis prevalence following the February 22, 2011 earthquake in Christchurch. The first focus was to assess whether earthquake-induced infrastructure damage, liquefaction, and gastroenteritis agents spatially explained the recorded gastroenteritis cases over the period of 35 days following the February 22, 2011 earthquake in Christchurch. The gastroenteritis agents considered in this study were Escherichia coli found in the drinking water supply (MPN/100mL) and Non-Compliant Free Associated Chlorine (FAC-NC) (less than <0.02mg/L). The second focus was the protocols that averted a gastroenteritis outbreak at three Emergency Centres (ECs): Burnside High School Emergency Centre (BEC); Cowles Stadium Emergency Centre (CEC); and Linwood High School Emergency Centre (LEC). Using a mixed-method approach, gastroenteritis point prevalence and the considered factors were quantitatively analysed. The qualitative analysis involved interviewing 30 EC staff members. The data was evaluated by adopting the Grounded Theory (GT) approach. Spatial analysis of considered factors showed that highly damaged CAUs were statistically clustered as demonstrated by Moran’s I statistic and hot spot analysis. Further modelling showed that gastroenteritis point prevalence clustering could not be fully explained by infrastructure damage alone, and other factors influenced the recorded gastroenteritis point prevalence. However, the results of this research suggest that there was a tenuous, indirect relationship between recorded gastroenteritis point prevalence and the considered factors: earthquake-induced infrastructure damage, liquefaction and FAC-NC. Two ECs were opened as part of the post-earthquake response in areas with severe infrastructure damage and liquefaction (BEC and CEC). The third EC (CEC) provided important lessons that were learnt from the previous September 4, 2010 earthquake, and implemented after the February 22, 2011 earthquake. Two types of interwoven themes identified: direct and indirect. The direct themes were preventive protocols and indirect themes included type of EC building (school or a sports stadium), and EC staff. The main limitations of the research were Modifiable Areal Units (MAUP), data detection, and memory loss. This research provides a practical method that can be adapted to assess gastroenteritis risk in a post-earthquake environment. Thus, this mixed method approach can be used in other disaster contexts to study gastroenteritis prevalence, and can serve as an appendage to the existing framework for assessing infectious diseases. Furthermore, the lessons learnt from qualitative analysis can inform the current infectious disease management plans, designed for a post-disaster response in New Zealand and internationally Using a mixed-method approach, gastroenteritis point prevalence and the considered factors were quantitatively analysed. A damage profile was created by amalgamating different types of damage for the considered factors for each Census Area Unit (CAU) in Christchurch. The damage profile enabled the application of a variety of statistical methods which included Moran’s I , Hot Spot (HS) analysis, Spearman’s Rho, and Besag–York–Mollié Model using a range of software. The qualitative analysis involved interviewing 30 EC staff members. The data was evaluated by adopting the Grounded Theory (GT) approach. Spatial analysis of considered factors showed that highly damaged CAUs were statistically clustered as demonstrated by Moran’s I statistic and hot spot analysis. Further modelling showed that gastroenteritis point prevalence clustering could not be fully explained by infrastructure damage alone, and other factors influenced the recorded gastroenteritis point prevalence. However, the results of this research suggest that there was a tenuous, indirect relationship between recorded gastroenteritis point prevalence and the considered factors: earthquake-induced infrastructure damage, liquefaction and FAC-NC. Two ECs were opened as part of the post-earthquake response in areas with severe infrastructure damage and liquefaction (BEC and CEC). The third EC (CEC) provided important lessons that were learnt from the previous September 4, 2010 earthquake, and implemented after the February 22, 2011 earthquake. The ECs were selected to represent the Christchurch area, and were situated where potential for gastroenteritis was high. BEC represented the western side of Christchurch; whilst, CEC and LEC represented the eastern side, where the potential for gastroenteritis was high according to the outputs of the quantitative spatial modelling. Qualitative analysis from the interviews at the ECs revealed that evacuees were arriving at the ECs with gastroenteritis-like symptoms. Participants believed that those symptoms did not originate at the ECs. Two types of interwoven themes identified: direct and indirect. The direct themes were preventive protocols that included prolific use of hand sanitisers; surveillance; and the services offered. Indirect themes included the EC layout, type of EC building (school or a sports stadium), and EC staff. Indirect themes governed the quality and sustainability of the direct themes implemented, which in turn averted gastroenteritis outbreaks at the ECs. The main limitations of the research were Modifiable Areal Units (MAUP), data detection, and memory loss. It was concluded that gastroenteritis point prevalence following the February 22, 2011 earthquake could not be solely explained by earthquake-induced infrastructure damage, liquefaction, and gastroenteritis causative agents alone. However, this research provides a practical method that can be adapted to assess gastroenteritis risk in a post-earthquake environment. Creating a damage profile for each CAU and using spatial data analysis can isolate vulnerable areas, and qualitative data analysis provides localised information. Thus, this mixed method approach can be used in other disaster contexts to study gastroenteritis prevalence, and can serve as an appendage to the existing framework for assessing infectious diseases. Furthermore, the lessons learnt from qualitative analysis can inform the current infectious disease management plans, designed for a post-disaster response in New Zealand and internationally.
Geological research in the immediate aftermath of the 2016 Kaikōura Earthquake, New Zealand, was necessary due to the importance and perishability of field data. It also reflects a real desire on the part of researchers to contribute not only to immediate scientific understanding but also to the societal recovery effort by enhancing knowledge of the event for the benefit of affected communities, civil defence organizations and regional and national decision makers. This commitment to outreach and engagement is consistent with the recent IAPG statement of Geoethics. More immediately, it was informed by experience of the 2010-2011 Canterbury Earthquake sequence. After that earlier disaster, intense interactions between researchers and various response agencies as well as local communities informed the development and dissemination of a set of ethical guidelines for researchers immediately following the Mw7.8 14 November 2016 Kaikōura Earthquake. In this presentation, I argue that ethical engagement of this kind is the key to gathering high quality research data immediately after the event. Creating trusting and mutually respectful, mutually beneficial relationships is also vital to ongoing engagement to facilitate further “in depth” research in collaboration with communities.
The magnitude Mw 6.2 earthquake of February 22nd 2011 that struck beneath the city of Christchurch, New Zealand, caused widespread damage and was particularly destructive to the Central Business District (CBD). The shaking caused major damage, including collapses of structures, and initiated ground failure in the form of soil liquefaction and consequent effects such as sand boils, surface flooding, large differential settlements of buildings and lateral spreading of ground towards rivers were observed. A research project underway at the University of Canterbury to characterise the engineering behaviour of the soils in the region was influenced by this event to focus on the performance of the highly variable ground conditions in the CBD. This paper outlines the methodology of this research to characterise the key soil horizons that underlie the CBD that influenced the performance of important structures during the recent earthquakes, and will influence the performance of the rebuilt city centre under future events. The methodology follows post-earthquake reconnaissance in the central city, a desk study on ground conditions, site selection, mobilisation of a post-earthquake ground investigation incorporating the cone penetration test (CPT), borehole drilling, shear wave velocity profiling and Gel-push sampling followed by a programme of laboratory testing including monotonic and cyclic testing of the soils obtained in the investigation. The research is timely and aims to inform the impending rebuild, with appropriate information on the soils response to dynamic loading, and the influence this has on the performance of structures with various foundation forms.
This article presents a subset of findings from a larger mixed methods CEISMIC1 funded study of twenty teachers’ earthquake experiences and post-earthquake adjustment eighteen months after a fatal earthquake struck Christchurch New Zealand, in the middle of a school day (Geonet Science, 2011; O’Toole & Friesen, 2016). This earthquake was a significant national and personal disaster with teachers’ emotional self-management as first responders being crucial to the students’ immediate safety (O’Toole & Friesen, 2016). At the beginning of their semi-structured interviews conducted eighteen months later, the teachers shared their earthquake stories (O’Toole & Friesen, 2016). They recalled the moment it struck in vivid detail, describing their experiences in terms of what they saw (destruction), heard (sonic boom, screaming children) and felt (fright and fear) as though they were back in that moment similar to flashbulb memory (Brown & Kulik, 1977). Their memories of the early aftermath were similarly vivid (Rubin & Kozin, 1984). This article focuses on how the mood meter (Brackett & Kremenitzer, 2011) was then used (with permission) to further explore the teachers’ perceived affect to enlighten their lived experiences.
The susceptibility of precast hollow-core floors to sustain critical damage during an earthquake is now well-recognized throughout the structural engineering community in New Zealand. The lack of shear reinforcement in these floor units is one of the primary reasons causing issues with the seismic performance of these floors. Recent research has revealed that the unreinforced webs of these floor units can crack at drift demands as low as 0.6%. Such observation indicates that potentially many of the existing building stock incorporating hollow-core flooring systems in cities of relatively high seismic activity (e.g. Wellington and Christchurch) that probably have already experienced a level of shaking higher than 0.6% drift in previous earthquakes might already have their floor units cracked. However, there is little information available to reliably quantify the residual gravity load-carrying capacity of cracked hollow-core floor units, highlighting the need to understand the post-cracking behavior of hollow-core floor units to better quantify the extent of the risk that cracked hollow-core floor units pose.
The paper examines community benefits provided by an established community garden following a major earthquake and discusses possible implications for community garden planning and design in disaster-prone cities. Recent studies show that following extreme storm events community gardens can supply food, enhance social empowerment, provide safe gathering spots, and restorative practices, to remind people of normality. However, the beneficial role played by community gardens following earthquakes is less well known. To fill this gap, the study examines the role played by a community garden in Christchurch, New Zealand, following the 2010/2011 Canterbury Earthquakes. The garden's role is evaluated based on a questionnaire-based survey and in-depth interviews with gardeners, as well as on data regarding the garden use before and after the earthquakes. Findings indicate the garden helped gardeners cope with the post-quake situation. The garden served as an important place to de-stress, share experiences, and gain community support. Garden features that reportedly supported disaster recovery include facilities that encourage social interaction and bonding such as central meeting and lunch places and communal working areas.
A Transitional Imaginary: Space, Network and Memory in Christchurch is the outcome and the record of a particular event: the coming together of eight artists and writers in Ōtautahi Christchurch in November 2015, with the ambitious aim to write a book collaboratively over five days. The collaborative process followed the generative ‘book sprint’ method founded by our facilitator for the event, Adam Hyde, who has long been immersed in digital practices in Aotearoa. A book sprint prioritises the collective voice of the participants and reflects the ideas and understandings that are produced at the time in which the book was written, in a plurality of perspectives. Over one hundred books have been completed using the sprint methodology, covering subjects from software documentation to reflections on collaboration and fiction. We chose to approach writing about Ōtautahi Christchurch through this collaborative process in order to reflect the complexity of the post-quake city and the multiple paths to understanding it. The city has itself been a space of intensive collaboration in the post-disaster period. A Transitional Imaginary is a raw and immediate record, as much felt expression as argued thesis. In many ways the process of writing had the character of endurance performance art. The process worked by honouring the different backgrounds of the participants, allowing that dialogue and intensity could be generative of different forms of text, creating a knowledge that eschews a position of authority, working instead to activate whatever anecdotes, opinions, resources and experiences are brought into discussion. This method enables a dynamic of voices that merge here, separate there and interrupt elsewhere again. As in the contested process of rebuilding and reimagining Christchurch itself, the dissonance and counterpoint of writing reflects the form of conversation itself. This book incorporates conflict, agreement and the activation of new ideas through cross-fertilisation to produce a new reading of the city and its transition. The transitional has been given a specific meaning in Christchurch. It is a product of local theorising that encompasses the need for new modes of action in a city that has been substantially demolished (Bennett & Parker, 2012). Transitional projects, such as those created by Gap Filler, take advantage of the physical and social spaces created by the earthquake through activating these as propositions for new ways of being in the city. The transitional is in motion, looking towards the future. A Transitional Imaginary explores the transitional as a way of thinking and how we understand the city through art practices, including the digital and in writing.
Research in the governance of urban tourist spaces is characterized by a lack of argumentative inquiry and scant use of critical theory. This is evident, particularly, in the study of tourism and post-disaster urban recovery, with very few contributions assessing the phenomenon from a social theory perspective. This thesis examines the complex phenomenon of planning and governance for urban tourism spaces in contexts facing physical recovery from natural disasters. It does so by looking at the governance dynamics and the mechanism of decision- making put in place before and after triggering events like earthquakes and tsunamis. This thesis provides evidence from Christchurch, New Zealand, by focusing on the policies and strategies for the regeneration of the city centre put in place before and after the disruptive earthquakes of 2010 and 2011. The thesis looks at power relations, structures and ideologies through a Lukesian appraisal of pre-and-post disaster governance from two relevant urban tourist spaces located in the Christchurch central city area: the Arts Centre of Christchurch and the Town Hall and Performing Arts Precinct. The research strategy adopted for the study combined archival research, interviews with key stakeholders and fieldwork notes over a period of two years. The research deployed a comparative case study methodology that focuses on projects taking place within a spatially defined area of the city centre where special legislation was enacted as result of the earthquakes. The findings from the interviews and their triangulation with documents retrieved from national and local authorities suggest that the earthquakes affected the engagement among stakeholders and the mechanisms of decision-making. Also, the findings show patterns of disaster capitalism in post-earthquake governance for urban tourist spaces in the Christchurch CBD, with episodes of exclusion, lobbying and amendment of rules and legislation that directly benefited the interests of a narrow group of privileged stakeholders. Overall, the study shows that the earthquakes of 2010 and 2011 accelerated neoliberal practices of site development in Christchurch, with the seismic events used as a pretext to implement market-oriented site projects in the CBD area.
The Canterbury region of New Zealand experienced four earthquakes greater than MW 6.0 between September 2010 and December 2011. This study employs system dynamics as well as hazard, recovery and organisational literature and brings together data collected via surveys, case studies and interviews with organisations affected by the earthquakes. This is to show how systemic interactions and interdependencies within and between industry and geographic sectors affect their recovery post-disaster. The industry sectors in the study are: construction for its role in the rebuild, information and communication technology which is a regional high-growth industry, trucking for logistics, critical infrastructure, fast moving consumer goods (e.g. supermarkets) and hospitality to track recovery through non-discretionary and discretionary spend respectively. Also in the study are three urban centres including the region’s largest Central Business District, which has been inaccessible since the earthquake of 22 February 2011 to the time of writing in February 2013. This work also highlights how earthquake effects propagated between sectors and how sectors collaborated to mitigate difficulties such as product demand instability. Other interacting factors are identified that influence the recovery trajectories of the different industry sectors. These are resource availability, insurance payments, aid from central government, and timely and quality recovery information. This work demonstrates that in recovering from disaster it is crucial for organisations to identify what interacting factors could affect their operations. Also of importance are efforts to reduce the organisation’s vulnerability and increase their resilience to future crises and in day-to-day operations. Lastly, the multi-disciplinary approach to understanding the recovery and resilience of organisations and industry sectors after disaster, leads to a better understanding of effects as well as more effective recovery policy.
This thesis is about many things, not least of all the September 4th 2010 and February 22nd 2011 earthquakes that shook Christchurch, New Zealand. A city was shaken, events which worked to lay open the normally invisible yet vital objects, processes and technologies which are the focus of inquiry: the sewers, pipes, pumps, the digital technologies, the land and politics which constitute the Christchurch wastewater networks. The thesis is an eclectic mix drawing together methods and concepts from Bruno Latour, John Law, Giles Deleuze and Felix Guattari, Nigel Thrift, Donna Haraway and Patrick Joyce. It is an exploration of how the technologies and objects of sanitation perform the city, and how such things which are normally hidden and obscured, are made visible. The question of visibility is also turned toward the research itself: how does one observe, and describe? How are sociological visibilities constructed? Through the research, the encountering of objects in the field, the processes of method, the pedagogy of concepts, and the construction of risk, the thesis comes to be understood as a particular kind of social scientific artefact which assembles four different accounts: the first regards the construction of visibility; the second explores Christchurch city from the control room where the urban sanitary infrastructures are monitored; the third chapter looks at the formatted and embodied practices which emerge with the correlation of the city and sanitation; the fourth looks at the changing politics of a city grappling with severely damaged essential services, land and structures. The final chapter considers how the differences between romantic and baroque sensibilities mean that these four accounts elicit knowing not through smoothness or uniformity, but in partiality and non-coherence. This thesis is about pipes, pump stations, and treatment plants; about the effluent of a city; about the messiness of social science when confronted by the equally messy world of wastewater.
The rapid classification of building damage states or placards after an earthquake is vital for enabling an efficient emergency response and informed decision-making for rehabilitation and recovery purposes. Traditional methods rely heavily on inspector-led on-site surveys, which are often time-consuming, resource-intensive, and susceptible to human error. This study introduces a machine learning-supported surrogate model designed to streamline the assessment of building damage, focusing on the automated assignment of damage placards within the context of New Zealand's post-earthquake evaluation frameworks. The study evaluates two key safety evaluation protocols—Rapid Building Assessment (RBA) and Detailed Damage Evaluation (DDE)—and integrates corresponding databases derived from the 2010–2011 Canterbury Earthquake Sequence (CES) in Christchurch. Six ML classifiers—Multilayer Perceptron (MLP), Random Forest (RF), Support Vector Machine (SVM), K-Nearest Neighbours (KNN), Gradient Boosting Classifier (GBC), and Gradient Bagging (GBag)—were rigorously tested across both databases. The results indicate that the RF-based surrogate model outperforms the other classifiers across both RBA and DDE protocols. Two distinct sets of critical predictors have been further identified for each protocol, allowing for the rapid retrieval of essential data for future on-site surveys, while retaining the RF model's predictive accuracy. The developed surrogate model provides a pragmatic tool for practising engineers to rapidly assign placards to damaged structures and for policymakers and building owners to make informed recovery decisions for earthquake-affected buildings.
Sewerage systems convey sewage, or wastewater, from residential or commercial buildings through complex reticulation networks to treatment plants. During seismic events both transient ground motion and permanent ground deformation can induce physical damage to sewerage system components, limiting or impeding the operability of the whole system. The malfunction of municipal sewerage systems can result in the pollution of nearby waterways through discharge of untreated sewage, pose a public health threat by preventing the use of appropriate sanitation facilities, and cause serious inconvenience for rescuers and residents. Christchurch, the second largest city in New Zealand, was seriously affected by the Canterbury Earthquake Sequence (CES) in 2010-2011. The CES imposed widespread damage to the Christchurch sewerage system (CSS), causing a significant loss of functionality and serviceability to the system. The Christchurch City Council (CCC) relied heavily on temporary sewerage services for several months following the CES. The temporary services were supported by use of chemical and portable toilets to supplement the damaged wastewater system. The rebuild delivery agency -Stronger Christchurch Infrastructure Rebuild Team (SCIRT) was created to be responsible for repair of 85 % of the damaged horizontal infrastructure (i.e., water, wastewater, stormwater systems, and roads) in Christchurch. Numerous initiatives to create platforms/tools aiming to, on the one hand, support the understanding, management and mitigation of seismic risk for infrastructure prior to disasters, and on the other hand, to support the decision-making for post-disaster reconstruction and recovery, have been promoted worldwide. Despite this, the CES in New Zealand highlighted that none of the existing platforms/tools are either accessible and/or readable or usable by emergency managers and decision makers for restoring the CSS. Furthermore, the majority of existing tools have a sole focus on the engineering perspective, while the holistic process of formulating recovery decisions is based on system-wide approach, where a variety of factors in addition to technical considerations are involved. Lastly, there is a paucity of studies focused on the tools and frameworks for supporting decision-making specifically on sewerage system restoration after earthquakes. This thesis develops a decision support framework for sewerage pipe and system restoration after earthquakes, building on the experience and learning of the organisations involved in recovering the CSS following the CES in 2010-2011. The proposed decision support framework includes three modules: 1) Physical Damage Module (PDM); 2) Functional Impact Module (FIM); 3) Pipeline Restoration Module (PRM). The PDM provides seismic fragility matrices and functions for sewer gravity and pressure pipelines for predicting earthquake-induced physical damage, categorised by pipe materials and liquefaction zones. The FIM demonstrates a set of performance indicators that are categorised in five domains: structural, hydraulic, environmental, social and economic domains. These performance indicators are used to assess loss of wastewater system service and the induced functional impacts in three different phases: emergency response, short-term recovery and long-term restoration. Based on the knowledge of the physical and functional status-quo of the sewerage systems post-earthquake captured through the PDM and FIM, the PRM estimates restoration time of sewer networks by use of restoration models developed using a Random Forest technique and graphically represented in terms of restoration curves. The development of a decision support framework for sewer recovery after earthquakes enables decision makers to assess physical damage, evaluate functional impacts relating to hydraulic, environmental, structural, economic and social contexts, and to predict restoration time of sewerage systems. Furthermore, the decision support framework can be potentially employed to underpin system maintenance and upgrade by guiding system rehabilitation and to monitor system behaviours during business-as-usual time. In conjunction with expert judgement and best practices, this framework can be moreover applied to assist asset managers in targeting the inclusion of system resilience as part of asset maintenance programmes.
Global biodiversity is threatened by human actions, including in urban areas. Urbanisation has removed and fragmented indigenous habitats. As one of the 25 biodiversity ’hot spots’, New Zealand is facing the problems of habitat loss and indigenous species extinction. In New Zealand cities, as a result of the land clearance and imported urban planning precepts, many urban areas have little or no original native forest remaining. Urbanisation has also been associated with the introduction of multitudes of species from around the world. Two large earthquakes shook Christchurch in 2010 and 2011 and caused a lot of damage. Parts of the city suffered from soil liquefaction after the earthquakes. In the most damaged parts of Christchurch, particularly in the east, whole neighbourhoods were abandoned and later demolished except for larger trees. Christchurch offers an excellent opportunity to study the biodiversity responses to an urban area with less intensive management, and to learn more about the conditions in urban environments that are most conducive to indigenous plant biodiversity. This study focuses on natural woody plant regeneration of forested sites in Christchurch city, many of which were also surveyed prior to the earthquakes. By repeating the pre-earthquake surveys, I am able to describe the natural regeneration occurring in Christchurch forested areas. By combining this with the regeneration that has occurred in the Residential Red Zone, successional trajectories can be described under a range of management scenarios. Using a comprehensive tree map of the Residential Red Zone, I was also able to document minimum dispersal distances of a range of indigenous trees in Christchurch. This is important for planning reserve connectivity. Moreover, I expand and improve on a previous analysis of the habitat connectivity of Christchurch (made before the earthquakes) to incorporate the Residential Red Zone, to assess the importance for habitat connectivity of restoring the indigenous forest in this area. In combination, these data sets are used to provide patch scenarios and some management options for biodiversity restoration in the Ōtākaro-Avon Red Zone post-earthquake.
This section considers forms of collaboration in situated and community projects embedded in important spatial transformation processes in New Zealand cities. It aims to shed light on specific combinations of material and semantic aspects characterising the relation between people and their environment. Contributions focus on participative urban transformations. The essays that follow concentrate on the dynamics of territorial production of associations between multiple actors belonging both to civil society and constituted authority. Their authors were directly engaged in the processes that are reported and conceptualised, thereby offering evidence gained through direct hands-on experience. Some of the investigations use case studies that are conspicuous examples of the recent post-traumatic urban development stemming from the Canterbury earthquakes of 2010-2011. More precisely, these cases belong to the early phases of the programmes of the Christchurch recovery or the Wellington seismic prevention. The relevance of these experiences for the scope of this study lies in the unprecedented height of public engagement at local, national and international levels, a commitment reached also due to the high impact, both emotional and concrete, that affected the entire society.
The 2010/2011 Canterbury earthquakes have provided a unique opportunity to investigate the seismic performance of both traditional and modern buildings constructed in New Zealand. It is critical that the observed performance is examined and compared against the expected levels of performance that are outlined by the Building Code and Design Standards. In particular, in recent years there has been a significant amount of research into the seismic behaviour of precast concrete floor systems and the robustness of the support connections as a building deforms during an earthquake. An investigation of precast concrete floor systems in Christchurch has been undertaken to assess both the performance of traditional and current design practice. The observed performance for each type of precast floor unit was collated from a number of post-earthquake recognisance activities and compared against the expected performance determined for previous experimental testing and analysis. Possible reasons for both the observed damage, and in some cases the lack of damage, were identified. This critical review of precast concrete floor systems will assist in determining the success of current design practice as well as identify any areas that require further research and/or changes to design standards.
Reinforced concrete buildings that satisfied modern seismic design criteria generally behaved as expected during the recent Canterbury and Kaikoura earthquakes in New Zealand, forming plastic hinges in intended locations. While this meant that life-safety performance objectives were met, widespread demolition and heavy economic losses took place in the aftermath of the earthquakes.The Christchurch central business district was particularly hard hit, with over 60% of the multistorey reinforced concrete buildings being demolished. A lack of knowledge on the post-earthquake residual capacity of reinforced concrete buildings was a contributing factor to the mass demolition.Many aspects related to the assessment of earthquake-damaged reinforced concrete buildings require further research. This thesis focusses on improving the state of knowledge on the post earthquakeresidual capacity and reparability of moderately damaged plastic hinges, with an emphasis on plastic hinges typical of modern moment frame structures. The repair method focussed on is epoxy injection of cracks and patching of spalled concrete. A targeted test program on seventeen nominally identical large-scale ductile reinforced concrete beams, three of which were repaired by epoxy injection following initial damaging loadings, was conducted to support these objectives. Test variables included the loading protocol, the loading rate, and the level of restraint to axial elongation.The information that can be gleaned from post-earthquake damage surveys is investigated. It is shown that residual crack widths are dependent on residual deformations, and are not necessarily indicative of the maximum rotation demands or the plastic hinge residual capacity. The implications of various other types of damage typical of beam and column plastic hinges are also discussed.Experimental data are used to demonstrate that the strength and deformation capacity of plastic hinges with modern seismic detailing are often unreduced as a result of moderate earthquake induced damage, albeit with certain exceptions. Special attention is given to the effects of prior yielding of the longitudinal reinforcement, accounting for the low-cycle fatigue and strain ageing phenomena. A material-level testing program on the low-cycle fatigue behaviour of grade 300E reinforcing steel was conducted to supplement the data available in the literature.A reduction in stiffness, relative to the initial secant stiffness to yield, occurs due to moderate plastic hinging damage. This reduction in stiffness is shown to be correlated with the ductility demand,and a proposed model gives a conservative lower-bound estimate of the residual stiffness following an arbitrary earthquake-type loading. Repair by epoxy injection is shown to be effective in restoring the majority of stiffness to plastic hinges in beams. Epoxy injection is also shown to have implications for the residual strength and elongation characteristics of repaired plastic hinges.
High demolition rates were observed in New Zealand after the 2010-2011 Canterbury Earthquake Sequence despite the success of modern seismic design standards to achieve required performance objectives such as life safety and collapse prevention. Approximately 60% of the multi-storey reinforced concrete (RC) buildings in the Christchurch Central Business District were demolished after these earthquakes, even when only minor structural damage was present. Several factors influenced the decision of demolition instead of repair, one of them being the uncertainty of the seismic capacity of a damaged structure. To provide more insight into this topic, the investigation conducted in this thesis evaluated the residual capacity of moderately damaged RC walls and the effectiveness of repair techniques to restore the seismic performance of heavily damaged RC walls. The research outcome provided insights for developing guidelines for post-earthquake assessment of earthquake-damaged RC structures. The methodology used to conduct the investigation was through an experimental program divided into two phases. During the first phase, two walls were subjected to different types of pre-cyclic loading to represent the damaged condition from a prior earthquake, and a third wall represented a repair scenario with the damaged wall being repaired using epoxy injection and repair mortar after the pre-cyclic loading. Comparisons of these test walls to a control undamaged wall identified significant reductions in the stiffness of the damaged walls and a partial recovery in the wall stiffness achieved following epoxy injection. Visual damage that included distributed horizontal and diagonal cracks and spalling of the cover concrete did not affect the residual strength or displacement capacity of the walls. However, evidence of buckling of the longitudinal reinforcement during the pre-cyclic loading resulted in a slight reduction in strength recovery and a significant reduction in the displacement capacity of the damaged walls. Additional experimental programs from the literature were used to provide recommendations for modelling the response of moderately damaged RC walls and to identify a threshold that represented a potential reduction in the residual strength and displacement capacity of damaged RC walls in future earthquakes. The second phase of the experimental program conducted in this thesis addressed the replacement of concrete and reinforcing steel as repair techniques for heavily damaged RC walls. Two walls were repaired by replacing the damaged concrete and using welded connections to connect new reinforcing bars with existing bars. Different locations of the welded connections were investigated in the repaired walls to study the impact of these discontinuities at the critical section. No significant changes were observed in the stiffness, strength, and displacement capacity of the repaired walls compared to the benchmark undamaged wall. Differences in the local behaviour at the critical section were observed in one of the walls but did not impact the global response. The results of these two repaired walls were combined with other experimental programs found in the literature to assemble a database of repaired RC walls. Qualitative and quantitative analyses identified trends across various parameters, including wall types, damage before repair, and repair techniques implemented. The primary outcome of the database analysis was recommendations for concrete and reinforcing steel replacement to restore the strength and displacement capacity of heavily damaged RC walls.
For 150,000 Christchurch school students, the 12.51 pm earthquake of 22 February 2011 shattered their normal lunch time activities and thrust their teachers into the role of emergency first responders. Whether helping students (children) escape immediate danger, or identifying and managing the best strategies for keeping children safe, including provision of extended caregiving when parents were unable to return to school to retrieve their children, teachers had to manage their own fears and trauma reactions in order to appear calm and prevent further distress for the children in their care. Only then did teachers return to their families. Eighteen months later, twenty teachers from across Christchurch, were interviewed. At 12.51pm, the teachers were essentially first responders. Using their usual methods for presenting a calm and professional image, the teachers’ emotion regulation (ER) strategies for managing their immediate fears were similar to those of professional first responders, with similar potential for subsequent burnout and negative emotional effects. Teachers’ higher emotional exhaustion and burnout 18 months later, were associated with school relocation. Lower burnout was associated with more emotional awareness, ER and perceived support. Consistent with international research, teachers’ use of cognitive reappraisal (re-thinking a situation) was an effective ER strategy, but this may not prevent teachers’ emotional resources from eventually becoming depleted. Teachers fulfill an important role in supporting children’s psychosocial adjustment following a natural disaster. However, as also acknowledged in international research, we need to also focus on supporting the teachers themselves.
The Christchurch earthquakes brought to an abrupt halt a process of adaptive reuse and gentrification that was underway in the south eastern corner of the central business district. The retail uses that were a key to the success of this area pre-earthquake could be characterised as small, owner operated, quirky, bohemian, chaotic and relatively low rent. This research reports on the progress of a long term, comprehensive case study that follows the progress of these retailers both before and after the earthquakes. Findings include the immediate post-earthquake intentions to resume business in the same location as soon as possible were thwarted by government imposed cordons of the CBD that were only lifted nearly three years later. But, businesses were resilient and generally reinvented themselves quickly in alternative suburban locations where government “rebuild” restrictions were absent. It remains to be seen if this type of retail will ever return to the CBD as government imposed plans and the rents demanded for retail space in new buildings appear to preclude small owner-operated businesses.
The Canterbury region of New Zealand was shaken by major earthquakes on the 4th September 2010 and 22nd February 2011. The quakes caused 185 fatalities and extensive land, infrastructure and building damage, particularly in the Eastern suburbs of Christchurch city. Almost 450 ha of residential and public land was designated as a ‘Red Zone’ unsuitable for residential redevelopment because land damage was so significant, engineering solutions were uncertain, and repairs would be protracted. Subsequent demolition of all housing and infrastructure in the area has left a blank canvas of land stretching along the Avon River corridor from the CBD to the sea. Initially the Government’s official – but enormously controversial – position was that this land would be cleared and lie fallow until engineering solutions could be found that enabled residential redevelopment. This paper presents an application of a choice experiment (CE) that identified and assessed Christchurch residents’ preferences for different land use options of this Red Zone. Results demonstrated strong public support for the development of a recreational reserve comprising a unique natural environment with native fauna and flora, healthy wetlands and rivers, and recreational opportunities that align with this vision. By highlighting the value of a range of alternatives, the CE provided a platform for public participation and expanded the conversational terrain upon which redevelopment policy took place. We conclude the method has value for land use decision-making beyond the disaster recovery context.
Collective identity construction in organisations engaged in an inter-organisational collaboration (IOC), especially temporary IOCs set up in disaster situations, has received scant attention in the organisational studies literature yet collective identity is considered to be important in fostering effective IOC operations. This doctoral study was designed to add to our understanding about how collective identity is constituted throughout the entire lifespan of a particular temporary coopetitive (i.e., simultaneously collaborative and competitive) IOC formed in a post-disaster environment. To achieve this purpose, a qualitative case study of the Stronger Christchurch Infrastructure Rebuild Team (SCIRT), a time-bound coopetition formed to repair the horizontal infrastructure in Christchurch, New Zealand after the devastating 2011 Canterbury earthquakes, was undertaken. Using data from semi-structured interviews, field observations, and organisational documents and other artefacts, an inductive analytic method was employed to explore how internal stakeholders engaged with and co- constructed a collective SCIRT identity and reconciled this with their home organization identity. The analysis revealed that the SCIRT collective identity was an ongoing process, involving the interweaving of social, temporal, material and geospatial dimensions constructed through intersecting cycles of senior managers’ sensegiving and employees’ sensemaking across SCIRT’s five and a half years of existence. Senior management deliberately undertook identity work campaigns that used organisational rituals, artefacts, and spatial design to disseminate and encourage a sense of “we are all SCIRT”. However, there was no common sense of “we-ness”. Identification with SCIRT was experienced differently among different groups of employees and across time. Employees’ differing senses of collective identity were accounted for by their past, present, and anticipated future relationships with their home organisation, and also (re)shaped by the geosocial environments in which they worked. The study supports previous research claiming that collective identity is a process of recursive sensegiving and sensemaking between senior managers and employees. However, it extends the literature by revealing the imbricated nature of collective identity, how members’ sense of “who we are” can change across the entire lifetime of a temporary IOC, and how sociomateriality, temporality, and geosocial effects strongly intervene in employees’ emerging senses of collective identity. Moreover, the study demonstrates how the ongoing identity work can be embedded in a time-space frame that further accentuates the influence of temporality, especially the anticipated future, organisational rituals, artefacts, and the geosocial environment. The study’s primary contribution to theory is a processual model of collective identity that applies specifically to a temporary IOC involving coopetition. In doing so, it represents a more finely nuanced and situational model than existing models. At a practical level, this model suggests that managers need to appreciate that organisational artefacts, rituals, and the prevailing organisational geosocial environment are inextricably linked in processes that can be manipulated to enhance the construction of collective identity.
The aftermath of three earthquakes has forced Christchurch to re-plan and rebuild. New perspectives of a sustainable city have arisen granting Christchurch the chance of becoming an example to the world. This work is centred on bioclimatic landscape design as a base for greening strategies. It deals with strategic landscape design adapted to a specific climate, from a user’s perspective. The investigation will be applied to Christchurch’s urban centres, assessing cultural adaptability to the local climate and implications for landscape design. Climatic data shows that humidity is not a local problem. However, the wind is the determinant. In Christchurch the solar radiation and the prevailing winds are the most important microclimatic variables, the latter intensifying the loss of surface heat, decreasing the radiant temperature and affecting thermal sensation. The research objective is to explore design parameters at the street-scale and identify ways to maximise thermal comfort in outdoor spaces through design-based strategies. The investigation will apply methods of participant observation, depth interviews, climatic data collection and design experimentation based on thermal comfort models and computer simulation tools. Case study sites chosen for investigation are places with current levels of activity that may be anticipated in the rebuild of the central city. The research will have two main outcomes: improved understanding of local urban culture adaptation to microclimate, and a demonstration of how design can enhance adaption. These outcomes will inform designers and city managers about good design practices and strategies that can be used to ensure a long term liveable city.
Natural disasters are highly traumatic for those who experience them, and they can have an immense and often lasting emotional impact (Cox et al., 2008). Emotion has been studied in linguistics through its enactment in language, and this field of research has increased over the past decades. Despite this, the expression of emotion in post-disaster narratives is a largely unexplored field of research. This thesis investigates how emotion is expressed in narratives taken from the QuakeBox corpus (Walsh et al., 2013), recorded, following the Christchurch earthquakes, in 2012 and rerecorded in 2019. I take a mixed methods approach, combining computer-based emotion recognition software and discourse analytic techniques, to explore the expression of emotion at both a broad and narrow level. Two emotion recognition programs, Empath (Fast et al., 2016) and Speechbrain (Ravanelli et al., 2021), are employed to measure the levels of positive and negative emotion detected in a wide dataset of participants, which are investigated in relation to the gender and age of participants, and the temporal difference between the first and second QuakeBox recordings. In a second phase, a subset of these participants’ narratives was analysed qualitatively, exploring the co-construction of emotion and identity through a social constructionist lens and examining the societal Discourses present in the earthquake narratives. The findings highlight the relevance of gender in the expression of emotion. Female speakers have higher levels of positive emotion than non-female speakers in the findings of both emotion recognition programs, and there is a clear gendered difference in the construction of identity in the narratives, influencing the expression of emotion. The expression of emotion also appears to be mediated by New Zealand culture. Within this, a Discourse of the Christchurch earthquakes emerges, with motifs of luck, gratitude, and community, which reflects the values of the people of Christchurch at the time. Findings reinforced in both phases of the analysis also indicate differences between the lexical content and acoustic features in the emotion expressions, supporting previous research that argues that the expression of emotion, as a performative act, does not reflect the speaker’s inner state directly. This research adds a new dimension to (socio)linguistic research on emotion, as well as providing insight into how crisis survivors display emotion in their post-disaster narratives.
This study explores the impact post-earthquake images from Christchurch, New Zealand inserted into a task requiring sustained attention or vigilance have on performance, selfreports of task-focus, and cerebra activity using functional near-infrared spectroscopy (fNIRS). The images represent the current state of Christchurch; a city struggling to recover from devastating earthquakes that peaked in February, 2011, killing 185 people, injuring hundreds more and causing widespread and massive damage to infrastructure, land and building in the region. Crowdsourcing was used to gather a series of positive and negative photos from greater Christchurch to be employed in the subsequent experiment. Seventy-one Christchurch resident participants (51 women, 20 men) then took part in a vigilance task with the sourced images embedded to assess possible cognitive disruptions. Participants were randomly assigned to one of three conditions: embedded positive pictures, embedded negative pictures, or embedded scrambled image controls. Task performance was assessed with signal detection theory metrics of sensitivity A’ and β’’. Individuals viewing the positive images, relating to progress, rebuild, or aesthetic aspects within the city, were overall more conservative or less willing to respond than those in the other conditions. In addition, positive condition individuals reported lower task focus, when compared to those in the control condition. However, indicators of cerebral activity (fNIRS) did not differ significantly between the experimental groups. These results combined, suggest that mind wandering events may be being generated when exposed to positive post-earthquake images. This finding fits with recent research which indicates that mind-wandering or day dreaming tends to be positive and future oriented. While positive recovery images may initiate internal thoughts, this could actually prove problematic in contexts in which external attention is required. While the actual environment, of course, needs to recover, support agencies may want to be careful with employing positive recovery imagery in contexts where people actually should be paying attention to something else, like operating a vehicle or machinery.
Diverse Density proposes an alternative housing strategy to the idealistic top-down process of housing development. The term ‘Top – down’ refers to a situation in which decisions are made by a few people in authority rather than by the people who are affected by the decisions (Cambridge). Problems/Position/Question: New Zealand’s urban housing is in a period of flux. Pressures of densification have permitted the intervention of medium density housing development schemes but these are not always successful. These typically top-down processes often result in internally focused design schemes that do not adhere to their specific context. The subsequent design outcomes can cause detrimental impacts to the local, urban and architectural conditions. With vast quantities of council regulations, building restrictions and design guidelines clouding over the housing sector, commonly referred to as ‘red tape’, occupant participation in the housing development sector is dwindling. A boundless separation between top-down and traditional housing processes has occurred and our existing neighbourhoods and historic architectural character are taking on the brunt of the problem. The thought-provoking, alternative housings strategies of key research theorists Alejandro Aravena and John Habraken frame positions that challenge contemporary densification methods with an alternative strategy. This position is addressed by endeavoring to answer; How can demands for denser housing achieve dynamic design responses that adhere to changes in occupancy, function and local site conditions? Aim: The aim of this thesis is to challenge New Zealand’s current housing densification methods by proposing an alternative densification strategy. Explicit devotion will be attributed to opposing top-down building developments. Secondly, this thesis aims to test a speculative site-specific housing model. The implementation of a Christchurch housing scenario will situate an investigative study to test the strategy and its ability to stimulate greater diversity, site responsiveness, functional adaptability and occupancy permutation. The post-earthquake housing conditions of Christchurch provide an appropriate scenario to test and implement design-led investigations. Objectives: The primary objectives of this design-led research investigation it to challenge the idealistic top-down method of developing density with a new method to: - Develop contextual architectural cohesion - Encourage residential diversity - Reinvigorate architectural autonomy - Respond to, and recognise, existing site conditions - Develop a housing model that: - Adapts to occupant functionality preferences - Caters to occupancy diversity - Achieves contextual responsiveness The proposition is addressed through a speculative design-led scenario study. A well-established Christchurch urban environment is adopted to implement and critique the envisioned alternative strategy. Development of the designs responsiveness, adaptability, and functionality produce a prototype housing model that actively adheres to its particular context. Implication: The implications of this research would be an alternative densification strategy to perceive the advancement of punctual assessment of building compliance. With accelerated building processes, the research may have implications for addressing New Zealand’s housing crisis whilst simultaneously providing diverse, personable and responsive architectural solutions. A more dynamic, up-to-date and responsive housing development sector would be informed.
The lived reality of the 2010-2011 Canterbury earthquakes and its implications for the Waimakariri District, a small but rapidly growing district (third tier of government in New Zealand) north of Christchurch, can illustrate how community well-being, community resilience, and community capitals interrelate in practice generating paradoxical results out of what can otherwise be conceived as a textbook ‘best practice’ case of earthquake recovery. The Waimakariri District Council’s integrated community based recovery framework designed and implemented post-earthquakes in the District was built upon strong political, social, and moral capital elements such as: inter-institutional integration and communication, participation, local knowledge, and social justice. This approach enabled very positive community outputs such as artistic community interventions of the urban environment and communal food forests amongst others. Yet, interests responding to broader economic and political processes (continuous central government interventions, insurance and reinsurance processes, changing socio-cultural patterns) produced a significant loss of community capitals (E.g.: social fragmentation, participation exhaustion, economic leakage, etc.) which simultaneously, despite local Council and community efforts, hindered community well-being in the long term. The story of the Waimakariri District helps understand how resilience governance operates in practice where multi-scalar, non-linear, paradoxical, dynamic, and uncertain outcomes appear to be the norm that underpins the construction of equitable, transformative, and sustainable pathways towards the future.
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.
Most people exposed to disasters cope well. Others, however, develop posttraumatic stress disorder (PTSD)–a mental disorder characterised by symptoms of intrusion, avoidance, and hyperarousal–requiring input from specialist mental health services. To date, relatively little research has evaluated these services, and less is known about characteristics of people seeking treatment and their treatment outcomes. In 2010 and 2011, a series of major earthquakes occurred in the Canterbury region of Aotearoa New Zealand, resulting in initiation of the Adult Specialist Services for Earthquake Trauma Treatment (ASSETT) service to provide cognitive behavioural therapy (CBT) for people with earthquake-related PTSD or subthreshold PTSD symptoms. The current research used systematic literature review methods, in conjunction with data collected from people seeking treatment with the ASSETT service, to address issues relevant to the development of disaster mental health responses, particularly specialist mental health services. A systematic review was conducted synthesising research examining mental health service use among adults exposed to natural disasters. A second systematic review and meta-analysis evaluated psychological interventions for earthquake-related PTSD. A series of studies then utilised diagnostic interview and self-report data collected from people seeking treatment with the ASSETT service (n = 184). Data were collected on factors relating to sociodemographics, pre-earthquake mental disorders, current psychological functioning, degree of objective and subjective earthquake exposure, and life events. These studies examined factors distinguishing treatment-seeking participants from earthquake-exposed Canterbury residents who coped well; differences associated with different prior mental disorders and timing of treatment presentation; and outcomes of CBT provided by the service. Four overarching themes emerged across study findings. The first related to the role of objective and subjective disaster exposure in the development of post-disaster mental health outcomes. Subjective peritraumatic responses were found to be an important factor distinguishing treatment-seeking participants from those who coped well following the earthquakes, independent of objective exposure severity. Heightened peritraumatic responses were also associated with poorer treatment outcome, although not beyond their association with pre-treatment PTSD severity and degree of comorbidity. The second theme related to the role of pre-trauma mental health in the development of post-disaster mental health outcomes. Participants with a history of pre-earthquake mental disorder presented with more comorbid disorders than participants with no prior disorder, but reported comparable degrees of PTSD severity and similar treatment outcomes. The third theme related to temporal considerations for disaster mental health responses. Participants who presented at later time points tended to be older and were more likely to have subthreshold PTSD symptoms, but had similar treatment outcomes as those who presented at earlier time points. The fourth theme related to treatment of severe and ongoing earthquake-related distress. CBT without a formal exposure component was associated with clinically significant improvements on a range of outcome measures, with group and individual-based treatment associated with comparable outcomes. Findings of the current research suggest people seeking treatment for severe and ongoing disaster-related distress are not homogenous, and are likely to present for treatment at different time points, have varied mental health histories, and report diverse disaster experiences. CBT is an effective treatment for severe and ongoing post-disaster distress when delivered in real-world mental health service settings. Group CBT represents an efficient, scalable, and effective treatment format for post-disaster distress, and may be an attractive option for treating widespread need using limited resources.
