There are many swaths of land that are deemed unsuitable to build on and occupy. These places, however, are rarely within an established city. The Canterbury earthquakes of 2010 and 2011 left areas in central Christchurch with such significant land damage that it is unlikely to be re-inhabited for a considerable period of time. These areas are commonly known as the ‘Red Zone’.This thesis explores redevelop in on volatile land through innovative solutions found and adapted from the traditional Indonesian construction techniques. Currently, Indonesia’s vernacular architecture sits on the verge of extinction after a cultural shift towards the masonry bungalow forced a rapid decline in their occupation and construction. The 2004 Indian Ocean earthquake and tsunami illustrated the bungalows’ poor performance in the face of catastrophic seismic activity, being outperformed by the traditional structures. This has been particularly evident in the Rumah Aceh construction of the Aceh province in Northern Sumatra. Within a New Zealand context an adaptation and modernisation of the Rumah Aceh construction will generate an architectural response not currently accepted under the scope of NZS 3604:2011; the standards most recent revision following the Canterbury earthquake of 2010 concerning timber-based seismic performance. This architectural exploration will further address light timber structures, their components, sustainability and seismic resilience. Improving new builds’ durability as New Zealand moves away from the previously promoted bungalow model that extends beyond residential and into all aspects of New Zealand built environment.
New Zealand has a long tradition of using light timber frame for construction of its domestic dwellings. After the most recent earthquakes (e.g. Canterbury earthquakes sequence), wooden residential houses showed satisfactory life safety performance. However, poor performance was reported in terms of their seismic resilience. Although numerous innovative methods to mitigate damage have been introduced to the New Zealand community in order to improve wooden house performance, these retrofit options have not been readily taken up. The low number of retrofitted wooden-framed houses leads to questions about whether homeowners are aware of the necessity of seismic retrofitting their houses to achieve a satisfactory seismic performance. This study aims to explore different retrofit technologies that can be applied to wooden-framed houses in Wellington, taking into account the need of homeowners to understand the risk, likelihood and extent of damage expected after an event. A survey will be conducted in Wellington about perceptions of homeowners towards the expected performance of their wooden-framed houses. The survey questions were designed to gain an understanding of homeowners' levels of safety and awareness of possible damage after a seismic event. Afterwards, a structural review of a sample of the houses will be undertaken to identify common features and detail potential seismic concerns. The findings will break down barriers to making improvements in the performance of wooden-framed houses and lead to enhancements in the confidence of homeowners in the event of future seismic activity. This will result in increased understanding and contribute towards an accessible knowledge base, which will possibly increase significantly the use of these technologies and avoid unnecessary economic and social costs after a seismic event.
Science education research shows that a traditional, stand-and-deliver lecture format is less effective than teaching strategies that are learner-centred and that promote active engagement. The Carl Wieman Science Education Initiative (CWSEI) has used this research to develop resources to improve learning in university science courses. We report on a successful adaptation and implementation of CWSEI in the New Zealand university context. This two-year project at Massey University and the University of Canterbury began by using perception and concept surveys before and after undergraduate science courses to measure students’ attitudes towards science as well as their knowledge. Using these data, and classroom observations of student engagement and corroborating focus groups, the research team worked with lecturers to create interventions to enhance student engagement and learning in those courses. Results show several positive changes related to these interventions and they suggest several recommendations for lecturers and course coordinators. The recommendations include:1. Make learning outcomes clear, both for the lecturer and the students; this helps to cull extraneous material and scaffold student learning. 2. Use interactive activities to improve engagement, develop deeper levels of thinking, and improve learning. 3. Intentionally foster “expert-like thinking” amongst students in the first few semesters of the degree programme. 4. Be flexible because one size does not fit all and contextual events are beyond anyone’s control.In addition to these recommendations, data collected at the Canterbury site during the 2010 and 2011 earthquakes reinforced the understanding that the most carefully designed teaching innovations are subject to contextual conditions beyond the control of academics.
Nowadays the telecommunication systems’ performance has a substantial impact on our lifestyle. Their operationality becomes even more substantial in a post-disaster scenario when these services are used in civil protection and emergency plans, as well as for the restoration of all the other critical infrastructure. Despite the relevance of loss of functionality of telecommunication networks on seismic resilience, studies on their performance assessment are few in the literature. The telecommunication system is a distributed network made up of several components (i.e. ducts, utility holes, cabinets, major and local exchanges). Given that these networks cover a large geographical area, they can be easily subjected to the effects of a seismic event, either the ground shaking itself, or co-seismic events such as liquefaction and landslides. In this paper, an analysis of the data collected after the 2010-2011 Canterbury Earthquake Sequence (CES) and the 2016 Kaikoura Earthquake in New Zealand is conducted. Analysing these data, information gaps are critically identified regarding physical and functional failures of the telecommunication components, the timeline of repair/reconstruction activities and service recovery, geotechnical tests and land planning maps. Indeed, if these missing data were presented, they could aid the assessment of the seismic resilience. Thus, practical improvements in the post-disaster collection from both a network and organisational viewpoints are proposed through consultation of national and international researchers and highly experienced asset managers from Chorus. Finally, an outline of future studies which could guide towards a more resilient seismic performance of the telecommunication network is presented.
Earthquake events can be sudden, stressful, unpredictable, and uncontrollable events in which an individual’s internal and external assumptions of their environment may be disrupted. A number of studies have found depression, and other psychological symptoms may be common after natural disasters. They have also found an association between depression, losses and disruptions for survivors. The present study compared depression symptoms in two demographically matched communities differentially affected by the Canterbury (New Zealand) earthquakes. Hypotheses were informed by the theory of learned helplessness (Abramson, Seligman & Teasdale, 1978). A door-to-door survey was conducted in a more physically affected community sample (N=67) and a relatively unaffected community sample (N=67), 4 months after the February 2011 earthquake. Participants were again assessed approximately 10 months after the quake. Measures of depression, acute stress, anxiety, aftershock anxiety, losses, physical disruptions and psychological disruptions were taken. In addition, prior psychological symptoms, medication, alcohol and cigarette use were assessed. Participants in the more affected community reported higher depression scores than the less affected community. Overall, elevated depressive score at time 2 were predicted by depression at time 1, acute stress and anxiety symptoms at time 2, physical disruptions following the quake and psychosocial functioning disruptions at time 2. These results suggest the influence of acute stress, anxiety and disruptions in predicting depression sometime after an earthquake. Supportive interventions directed towards depression, and other psychological symptoms, may prove helpful in psychological adjustment following ongoing disruptive stressors and uncontrollable seismic activity.
The research presented in this thesis investigated the environmental impacts of structural design decisions across the life of buildings located in seismic regions. In particular, the impacts of expected earthquake damage were incorporated into a traditional life cycle assessment (LCA) using a probabilistic method, and links between sustainable and resilient design were established for a range of case-study buildings designed for different seismic performance objectives. These links were quantified using a metric herein referred to as the seismic carbon risk, which represents the expected environmental impacts and resource use indicators associated with earthquake damage during buildings’ life. The research was broken into three distinct parts: (1) a city-level evaluation of the environmental impacts of demolitions following the 2010/2011 Canterbury earthquake sequence in New Zealand, (2) the development of a probabilistic framework to incorporate earthquake damage into LCA, and (3) using case-study buildings to establish links between sustainable and resilient design. The first phase of the research focused on the environmental impacts of demolitions in Christchurch, New Zealand following the 2010/2011 Canterbury Earthquake Sequence. This large case study was used to investigate the environmental impact of the demolition of concrete buildings considering the embodied carbon and waste stream distribution. The embodied carbon was considered here as kilograms of CO2 equivalent that occurs on production, construction, and waste management stage. The results clearly demonstrated the significant environmental impacts that can result from moderate and large earthquakes in urban areas, and the importance of including environmental considerations when making post-earthquake demolition decisions. The next phase of the work introduced a framework for incorporating the impacts of expected earthquake damage based on a probabilistic approach into traditional LCA to allow for a comparison of seismic design decisions using a carbon lens. Here, in addition to initial construction impacts, the seismic carbon risk was quantified, including the impacts of seismic repair activities and total loss scenarios assuming reconstruction in case of non-reparability. A process-based LCA was performed to obtain the environmental consequence functions associated with structural and non-structural repair activities for multiple environmental indicators. In the final phase of the work, multiple case-study buildings were used to investigate the seismic consequences of different structural design decisions for buildings in seismic regions. Here, two case-study buildings were designed to multiple performance objectives, and the upfront carbon costs, and well as the seismic carbon risk across the building life were compared. The buildings were evaluated using the framework established in phase 2, and the results demonstrated that the seismic carbon risk can significantly be reduced with only minimal changes to the upfront carbon for buildings designed for a higher base shear or with seismic protective systems. This provided valuable insight into the links between resilient and sustainable design decisions. Finally, the results and observations from the work across the three phases of research described above were used to inform a discussion on important assumptions and topics that need to be considered when quantifying the environmental impacts of earthquake damage on buildings. These include: selection of a non-repairable threshold (e.g. a value beyond which a building would be demolished rather than repaired), the time value of carbon (e.g. when in the building life the carbon is released), the changing carbon intensity of structural materials over time, and the consideration of deterministic vs. probabilistic results. Each of these topics was explored in some detail to provide a clear pathway for future work in this area.
Study region: Christchurch, New Zealand. Study focus: Low-lying coastal cities worldwide are vulnerable to shallow groundwater salinization caused by saltwater intrusion and anthropogenic activities. Shallow groundwater salinization can have cascading negative impacts on municipal assets, but this is rarely considered compared to impacts of salinization on water supply. Here, shallow groundwater salinity was sampled at high spatial resolution (1.3 piezometer/km2 ), then mapped and spatially interpolated. This was possible due to a uniquely extensive set of shallow piezometers installed in response to the 2010–11 Canterbury Earthquake Sequence to assess liquefaction risk. The municipal assets located within the brackish groundwater areas were highlighted. New hydrological insights for the region: Brackish groundwater areas were centred on a spit of coastal sand dunes and inside the meander of a tidal river with poorly drained soils. The municipal assets located within these areas include: (i) wastewater and stormwater pipes constructed from steel-reinforced concrete, which, if damaged, are vulnerable to premature failure when exposed to chloride underwater, and (ii) 41 parks and reserves totalling 236 ha, within which salt-intolerant groundwater-dependent species are at risk. This research highlights the importance of determining areas of saline shallow groundwater in low-lying coastal urban settings and the co-located municipal assets to allow the prioritisation of sites for future monitoring and management.
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 previously unknown Greendale Fault was buried beneath the Canterbury Plains and ruptured in the September 4th 2010 moment magnitude (Mw) 7.1 Darfield Earthquake. The Darfield Earthquake and subsequent Mw 6 or greater events that caused damage to Christchurch highlight the importance of unmapped faults near urban areas. This thesis examines the morphology, age and origin of the Canterbury Plains together with the paleoseismology and surface-rupture displacement distributions of the Greendale Fault. It offers new insights into the surface-rupture characteristics, paleoseismology and recurrence interval of the Greendale Fault and related structures involved in the 2010 Darfield Earthquake. To help constrain the timing of the penultimate event on the Greendale Fault the origin and age of the faulted glacial outwash deposits have been examined using sedimentological analysis of gravels and optically stimulated luminescence (OSL) dating combined with analysis of GPS and LiDAR survey data. OSL ages from this and other studies, and the analysis of surface paleochannel morphology and subsurface gravel deposits indicate distinct episodes of glacial outwash activity across the Canterbury Plains, at ~20 to 24 and ~28 to 33 kyr separated by a hiatus in sedimentation possibly indicating an interstadial period. These data suggest multiple glacial periods between ~18 and 35 kyr which may have occurred throughout the Canterbury region and wider New Zealand. A new model for the Waimakariri Fan is proposed where aggradation is mainly achieved during episodic sheet flooding with the primary river channel location remaining approximately fixed. The timing, recurrence interval and displacements of the penultimate surface-rupturing earthquake on the Greendale Fault have been constrained by trenching the scarp produced in 2010 at two locations. These excavations reveal a doubling of the magnitude of surface displacement at depths of 2-4 m. Aided by OSL ages of sand lenses in the gravel deposits, this factor-of-two increase is interpreted to indicate that in the central section of the Greendale Fault the penultimate surface-rupturing event occurred between ca. 20 and 30 kyr ago. The Greendale Fault remained undetected prior to the Darfield earthquake because the penultimate fault scarp was eroded and buried during Late Pleistocene alluvial activity. The Darfield earthquake rupture terminated against the Hororata Anticline Fault (HAF) in the west and resulted in up to 400 mm of uplift on the Hororata Anticline immediately above the HAF. Folding in 2010 is compared to Quaternary and younger deformation across the anticline recorded by a seismic reflection line, GPS-measured topographic profiles along fluvial surfaces, and river channel sinuosity and morphology. It is concluded that the HAF can rupture during earthquakes dissimilar to the 2010 event that may not be triggered by slip on the Greendale Fault. Like the Greendale Fault geomorphic analyses provide no evidence for rupture of the HAF in the last 18 kyr, with the average recurrence interval for the late Quaternary inferred to be at least ~10 kyr. Surface rupture of the Greendale Fault during the Darfield Earthquake produced one of the most accessible and best documented active fault displacement and geometry datasets in the world. Surface rupture fracture patterns and displacements along the fault were measured with high precision using real time kinematic (RTK) GPS, tape and compass, airborne light detection and ranging (LiDAR), and aerial photos. This allowed for detailed analysis of the cumulative strike-slip displacement across the fault zone, displacement gradient (ground shear strain) and the type of displacement (i.e. faulting or folding). These strain profiles confirm that the rupture zone is generally wide (~30 to ~300 metres) with >50% of displacement (often 70-80%) accommodated by ground flexure rather than discrete fault slip and ground cracking. The greatest fault-zone widths and highest proportions of folding are observed at fault stepovers.
Following the devastation of the Canterbury earthquake sequence a unique opportunity exists to rebuild and restructure the city of Christchurch, ensuring that its infrastructure is constructed better than before and is innovative. By installing an integrated grid of modern sensor technologies into concrete structures during the rebuild of the Christchurch CBD, the aim is to develop a network of self-monitored ‘digital buildings’. A diverse range of data will be recorded, potentially including parameters such as concrete stresses, strains, thermal deformations, acoustics and the monitoring of corrosion of reinforcement bars. This procedure will allow an on-going complete assessment of the structure’s performance and service life, both before and after seismic activity. The data generated from the embedded and surface mounted sensors will be analysed to allow an innovative and real-time health monitoring solution where structural integrity is continuously known. This indication of building performance will allow the structure to alert owners, engineers and asset managers of developing problems prior to failure thresholds being reached. A range of potential sensor technologies for monitoring the performance of existing and newly constructed concrete buildings is discussed. A description of monitoring work conducted on existing buildings during the July 2013 Cook Strait earthquake sequence is included, along with details of current work that investigates the performance of sensing technologies for detecting crack formation in concrete specimens. The potential market for managing the real-time health of installed infrastructure is huge. Civil structures all over the world require regular visual inspections in order to determine their structural integrity. The information recorded during the Christchurch rebuild will generate crucial data sets that will be beneficial in understanding the behaviour of concrete over the complete life cycle of the structure, from construction through to operation and building repairs until the time of failure. VoR - Version of Record
Disasters, either man-made or natural, are characterised by a multiplicity of factors including loss of property, life, environmental degradation, and psychosocial malfunction of the affected community. Although much research has been undertaken on proactive disaster management to help reduce the impacts of natural and man-made disasters, many challenges still remain. In particular, the desire to re-house the affected as quickly as possible can affect long-term recovery if a considered approach is not adopted. Promoting recovery activities, coordination, and information sharing at national and international levels are crucial to avoid duplication. Mannakkara and Wilkinson’s (2014) modified “Build Back Better” (BBB) concept aims for better resilience by incorporating key resilience elements in post-disaster restoration. This research conducted an investigation into the effectiveness of BBB in the recovery process after the 2010–2011 earthquakes in greater Christchurch, New Zealand. The BBB’s impact was assessed in terms of its five key components: built environment, natural environment, social environment, economic environment, and implementation process. This research identified how the modified BBB propositions can assist in disaster risk reduction in the future, and used both qualitative and quantitative data from both the Christchurch and Waimakariri recovery processes. Semi-structured interviews were conducted with key officials from the Christchurch Earthquake Recovery Authority, and city councils, and supplemented by reviewing of the relevant literature. Collecting data from both qualitative and quantitative sources enabled triangulation of the data. The interviewees had directly participated in all phases of the recovery, which helped the researcher gain a clear understanding of the recovery process. The findings led to the identification of best practices from the Christchurch and Waimakariri recovery processes and underlined the effectiveness of the BBB approach for all recovery efforts. This study contributed an assessment tool to aid the measurement of resilience achieved through BBB indicators. This tool provides systematic and structured approach to measure the performance of ongoing recovery.
Urban Ensembles explores the way in which landscape and architecture can be employed together within the design of a steep, urban site. Lyttelton is a small port town on the border of Christchurch, settled in the foothills of a harbour formed by a major volcanic eruption. This rugged setting, with steeply sloping urban terrain, presents an interesting challenge when designing an urban development. The site was badly damaged in a series of earthquakes in 2010-2011, and many of the town’s oldest buildings, heritage structures dating back to the colonial settlement era, were destroyed. This has left a void in the heart of Lyttelton, and caused the loss of much of the tourism business that the town relies upon for its income. This thesis takes a methodological approach to the design of landscape architecture on such a challenging site. A range of techniques are explored, drawing from both landscape and architecture to explore the roles that each discipline plays in the design of urban spaces. The frequent imbalance between disciplines is addressed both through the literature review and design method, as this landscape architecture thesis draws on architectural design as a tool for generating spaces which fall somewhere in between the two ideals of interior and exterior. The final design proposal is an alternative rebuild plan for the central business area to the south of London St, and also addresses the relationships between that site and the surrounding context, both urban and environmental. The aim of this design is to create a series of interconnected spaces which have a strong relationship to the surrounding harbour setting, and also to facilitate development of the pedestrian spaces throughout the block and encouraging the development of activity at the street level, through the interface between buildings and landscape.
School travel is a major aspect of a young person’s everyday activity. The relationship between the built environment that youth experience on their way to and from school, influences a number of factors including their development, health and wellbeing. This is especially important in low income areas where the built environment is often poorer, but the need for it to be high quality and accessible is greater. This study focusses on the community of Aranui, a relatively low income suburb in Christchurch, New Zealand. It pays particular attention to Haeata Community Campus, a state school of just under 800 pupils from year one through to year thirteen (ages 5-18). The campus opened in 2017 following the closure of four local schools (three primary and one secondary), as part of the New Zealand Government’s Education Renewal scheme following the Christchurch earthquakes of 2010/11. Dedicated effort toward understanding the local built environment, and subsequent travel patterns has been argued to be insufficiently considered. The key focus of this research was to understand the importance of the local environment in encouraging active school travel. The present study combines geospatial analysis, quantitative survey software Maptionnaire, and statistical models to explore the features of the local environment that influence school travel behaviour. Key findings suggest that distance to school and parental control are the most significant predictors of active transport in the study sample. Almost 75% of students live within two kilometres of the school, yet less than 40% utilise active transport. Parental control may be the key contributing factor to the disproportionate private vehicle use. However, active school travel is acknowledged as a complex process that is the product of many individual, household, and local environment factors. To see increased active transport uptake, the local environment needs to be of greater quality. Meaning that the built environment should be improved to be youth friendly, with greater walkability and safe, accessible cycling infrastructure.
This study explored the effects of the Canterbury earthquakes of 2010 and 2011 on different areas of quality of life (QOL) for children and adolescents with disabilities. Using a survey developed from the Quality of Life Instrument for People with Developmental Disabilities – Short Version (QOL-PDD-SV) (Brown, Raphael & Renwick, 1997) and The World Health Organisation Quality of Life - (WHOQOL)-BREF, parents or caregivers were asked to identify what level of importance and satisfaction their child or adolescent placed on areas of QOL including physical health, psychological health - stress levels and coping ability, attachment to their neighbourhood, friends, family, leisure activities, community access and schooling. They were also asked to determine what level of impact the earthquakes had had on each area of their child or adolescent’s life and overall quality of life in the aftermath of the earthquakes. A total of 31 parents of 22 males and 9 females between the ages of 2.5 years to 19 years of age (mean age: 12.6 years) responded. The results were collated and analysis was run to measure for the effect of age, gender and geographical location. The results found that the earthquakes affected nearly every area of QOL for the children and adolescents. The biggest impact on the children’s psychological health and their ability to cope It was observed that younger children (<13) were more likely to record improved or lessened effects from the earthquakes in psychological health areas. However, the areas of social belonging and friendships were the least affected by the earthquakes. Female children were more likely to indicate higher scores for social belonging after the earthquakes. Many parents observed that their children developed improved coping skills over the earthquake period. The findings in this study offer a better understanding of how earthquakes can affect the quality of life children and adolescents with disabilities.
Organisations locate strategically within Business Districts (CBDs) in order to cultivate their image, increase their profile, and improve access to customers, suppliers, and services. While CBDs offer an economic benefit to organisations, they also present a unique set of hazard vulnerabilities and planning challenges for businesses. As of May 2012, the Christchurch CBD has been partially cordoned off for over 14 months. Economic activity within the cordoned CBD, which previously contained 6,000 businesses and over 51,000 workers, has been significantly diminished and organisations have been forced to find new ways of operating. The vulnerabilities and resilience of CBDs not only influences outcomes for CBD organisations, but also the broader interconnected (urban/regional/national) system. A CBD is a hub of economic, social, and built infrastructure within a network of links and nodes. When the hub is disrupted all of the people, objects, and transactions that usually flow into and out of the hub must be redirected elsewhere. In an urban situation this means traffic jams in peripheries of the city, increased prices of commercial property, and capital flight; all of which are currently being faced in Canterbury. This report presents the lessons learned from organisations in CBDs affected by the Canterbury earthquakes. Here we focus on the Christchurch CBD; however, several urban town centres were extensively disrupted by the earthquakes. The statistics and discussion presented in this report are based on the results of an ongoing study conducted by Resilient Organisations (www.resorgs.org.nz). The data was captured using two questionnaire surveys of Canterbury organisations (issued November 2010 and May 2011), interviews with key informants, and in-depth case studies of organisations. Several industry sectors were sampled, and geographic samples of organisations in the Christchurch CBD, Lyttelton, and the Kaiapoi town centre were also collected. Results in this report describing “non-CBD organisations” refer to all organisations outside of the Christchurch CBD, Lyttelton, and Kaiapoi town centres.
On 22 February 2011，a magnitude Mw 6.3 earthquake occurred with an epicenter located near Lyttelton at about 10km from Christchurch in Canterbury region on the South Island of New Zealand (Figure 1). Since this earthquake occurred in the midst of the aftershock activity which had continued since the 4 September 2010 Darfield Earthquake occurrence, it was considered to be an aftershock of the initial earthquake. Because of the short distance to the city and the shallower depth of the epicenter, this earthquake caused more significant damage to pipelines, traffic facilities, residential houses/properties and multi-story buildings in the central business district than the September 2010 Darfield Earthquake in spite of its smaller earthquake magnitude. Unfortunately, this earthquake resulted in significant number of casualties due to the collapse of multi-story buildings and unreinforced masonry structures in the city center of Christchurch. As of 4 April, 172 casualties were reported and the final death toll is expected to be 181. While it is extremely regrettable that Christchurch suffered a terrible number of victims, civil and geotechnical engineers have this hard-to-find opportunity to learn the response of real ground from two gigantic earthquakes which occurred in less than six months from each other. From geotechnical engineering point of view, it is interesting to discuss the widespread liquefaction in natural sediments, repeated liquefaction within short period and further damage to earth structures which have been damaged in the previous earthquake. Following the earthquake, an intensive geotechnical reconnaissance was conducted to capture evidence and perishable data from this event. The team included the following members: Misko Cubrinovski (University of Canterbury, NZ, Team Leader), Susumu Yasuda (Tokyo Denki University, Japan, JGS Team Leader), Rolando Orense (University of Auckland, NZ), Kohji Tokimatsu (Tokyo Institute of Technology, Japan), Ryosuke Uzuoka (Tokushima University, Japan), Takashi Kiyota (University of Tokyo, Japan), Yasuyo Hosono (Toyohashi University of Technology, Japan) and Suguru Yamada (University of Tokyo, Japan).
The 2010-2011 Canterbury Earthquakes brought devastation to the city of Christchurch and has irrevocably affected the lives of the city’s residents. Years after the conclusion of these earthquakes, Christchurch and its residents are well on the path to recovery. Crime has proven an ongoing topic of discussion throughout this period, with news reports of increased burglary and arson in areas left largely abandoned by earthquake damage, and a rise in violent crime in suburban areas of Christchurch. Following the body of research that has considered the reaction of crime to natural disasters, this research has sought to comprehensively examine and understand the effects that the Canterbury Earthquakes had on crime. Examining Christchurch-wide offending, crime rates fell over the study period (July 2008 to June 2013), with the exception of domestic violence. Aside from a momentary increase in burglary in the days immediately following the Christchurch Earthquake, crime rates (as of 2013) have remained largely below pre-earthquake levels. Using Dual Kernel Density Estimation Analysis, a distinct spatial change in pre-earthquake crime hotspots was observed. These changes included an enormous decrease in central city offences, a rise in burglary in the eastern suburbs, and an increase in assault in areas outside of the central city. Logistic regression analysis, using a time-compensated dependent variable, identified a number of statistically-significant relationships between per CAU crime rate change and factors measuring socio-demographic characteristics, community cohesion, and the severity of disaster effects. The significance of these findings was discussed using elements of Social Disorganisation Theory, Routine Activity Theory, and Strain Theory. Consistent with past findings, social order was largely maintained following the Canterbury Earthquakes, with suggestion that increased collective efficacy and therapeutic communities had a negative influence on crime in the post-earthquake period. Areas of increased burglary and assault were associated with large population decreases, suggesting a link with the dissolution of communities and the removal of their inherent informal guardianship. Though observed, the increase in domestic violence was not associated with most neighbourhood-level variables. Trends in crime after the Canterbury Earthquakes were largely consistent with past research, and the media’s portrayal.
Geologic phenomena produced by earthquake shaking, including rockfalls and liquefaction features, provide important information on the intensity and spatiotemporal distribution of earthquake ground motions. The study of rockfall and liquefaction features produced in contemporary well- instrumented earthquakes increases our knowledge of how natural and anthropogenic environments respond to earthquakes and improves our ability to deduce seismologic information from analogous pre-contemporary (paleo-) geologic features. The study of contemporary and paleo- rockfall and liquefaction features enables improved forecasting of environmental responses to future earthquakes. In this thesis I utilize a combination of field and imagery-based mapping, trenching, stratigraphy, and numerical dating techniques to understand the nature and timing of rockfalls (and hillslope sedimentation) and liquefaction in the eastern South Island of New Zealand, and to examine the influence that anthropogenic activity has had on the geologic expressions of earthquake phenomena. At Rapaki (Banks Peninsula, NZ), field and imagery-based mapping, statistical analysis and numerical modeling was conducted on rockfall boulders triggered by the fatal 2011 Christchurch earthquakes (n=285) and compared with newly identified prehistoric (Holocene and Pleistocene) boulders (n=1049) deposited on the same hillslope. A significant population of modern boulders (n=26) travelled farther downslope (>150 m) than their most-travelled prehistoric counterparts, causing extensive damage to residential dwellings at the foot of the hillslope. Replication of prehistoric boulder distributions using 3-dimensional rigid body numerical models requires the application of a drag-coefficient, attributed to moderate to dense slope vegetation, to account for their spatial distribution. Radiocarbon dating provides evidence for 17th to early 20th century deforestation at the study site during Polynesian and European colonization and after emplacement of prehistoric rockfalls. Anthropocene deforestation enabled modern rockfalls to exceed the limits of their prehistoric predecessors, highlighting a shift in the geologic expression of rockfalls due to anthropogenic activity. Optical and radiocarbon dating of loessic hillslope sediments in New Zealand’s South Island is used to constrain the timing of prehistoric rockfalls and associated seismic events, and quantify spatial and temporal patterns of hillslope sedimentation including responses to seismic and anthropogenic forcing. Luminescence ages from loessic sediments constrain timing of boulder emplacement to between ~3.0 and ~12.5 ka, well before the arrival of Polynesians (ca AD 1280) and Europeans (ca AD 1800) in New Zealand, and suggest loess accumulation was continuing at the study site until 12-13 ka. Large (>5 m3) prehistoric rockfall boulders preserve an important record of Holocene hillslope sedimentation by creating local traps for sediment aggradation and upbuilding soil formation. Sediment accumulation rates increased considerably (>~10 factor increase) following human arrival and associated anthropogenic burning of hillslope vegetation. New numerical ages are presented to place the evolution of loess-mantled hillslopes in New Zealand’s South Island into a longer temporal framework and highlight the roles of earthquakes and humans on hillslope surface process. Extensive field mapping and characterization for 1733 individual prehistoric rockfall boulders was conducted at Rapaki and another Banks Peninsula site, Purau, to understand their origin, frequency, and spatial and volumetric distributions. Boulder characteristics and distributions were compared to 421 boulders deposited at the same sites during the 2010-2011 Canterbury earthquake sequence. Prehistoric boulders at Rapaki and Purau are comprised of two dominant lithofacies types: volcanic breccia and massive (coherent) lava basalt. Volcanic breccia boulders are found in greatest abundance (64-73% of total mapped rockfall) and volume (~90-96% of total rockfall) at both locations and exclusively comprise the largest boulders with the longest runout distances that pose the greatest hazard to life and property. This study highlights the primary influence that volcanic lithofacies architecture has on rockfall hazard. The influence of anthropogenic modifications on the surface and subsurface geologic expression of contemporary liquefaction created during the 2010-2011 Canterbury earthquake sequence (CES) in eastern Christchurch is examined. Trench observations indicate that anthropogenic fill layer boundaries and the composition/texture of discretely placed fill layers play an important role in absorbing fluidized sand/silt and controlling the subsurface architecture of preserved liquefaction features. Surface liquefaction morphologies (i.e. sand blows and linear sand blow arrays) display alignment with existing utility lines and utility excavations (and perforated pipes) provided conduits for liquefaction ejecta during the CES. No evidence of pre-CES liquefaction was identified within the anthropogenic fill layers or underlying native sediment. Radiocarbon dating of charcoal within the youngest native sediment suggests liquefaction has not occurred at the study site for at least the past 750-800 years. The importance of systematically examining the impact of buried infrastructure on channelizing and influencing surface and subsurface liquefaction morphologies is demonstrated. This thesis highlights the importance of using a multi-technique approach for understanding prehistoric and contemporary earthquake phenomena and emphasizes the critical role that humans play in shaping the geologic record and Earth’s surface processes.
A Line of Best Fit explores weakness and disconnection in the city. Weakness: There are over 600 earthquake prone buildings in Wellington. The urgency to strengthen buildings risks compromising the aesthetic integrity of the city through abrasive strengthening techniques, or losing a large portion of our built environment to demolition. The need for extensive earthquake strengthening in Wellington, Christchurch and other New Zealand cities provides an exciting opportunity for architecture. Disconnection: In Wellington pedestrian activity is focused around three main routes: Cuba Street, Lambton Quay and Courtney Place. The adjacent areas are often disconnected and lack vibrancy due to large building footprints, no-exit laneways and lack of public spaces. The Design proposes a strategy for earthquake strengthening, preserving and upgrading the built environment, and expanding and connecting the pedestrian realm. The site is two earthquake prone buildings on the block between Marion Street and Taranaki Street in central Wellington. A cut through the centre of the Aspro and Cathie Buildings ties the buildings together to strengthen and create a new arcade as public space. The cut aligns with existing pedestrian routes connecting the block with the city. The Design is divided into three components: Void, Curve, and Pattern and Structure. Void investigates the implications of cutting a portion out the existing buildings and the opportunities this provides for connection, urban interaction, and light. Curve discusses the unusual form of The Design in terms of scale, the human response and the surrounding spaces. Pattern and Structure considers the structural requirements of the project and how a void enveloped in perforated screens can strengthen the earthquake prone buildings. The importance of connection, providing strength in the city, a dialogue between old and new, and engagement with the unexpected are evaluated. Opportunities for further development and research are discussed, with particular reference to how the principles of The Design could be implemented on a larger scale throughout our cities. A Line of Best Fit is an architectural proposal that creates strength and connection.
Floor systems with precast concrete hollow-core units have been largely used in concrete buildings built in New Zealand during the 1980’s. Recent earthquakes, such as the Canterbury sequence in 2010-2011 and the Kaikoura earthquake in 2016, highlighted that this floor system can be highly vulnerable and potentially lead to the floor collapse. A series of research activities are in progress to better understand the seismic performance of floor diaphragms, and this research focuses on examining the performance of hollow core units running parallel to the walls of wall-resisting concrete structures. This study first focused on the development of fragility functions, which can be quickly used to assess likelihood of the hollow-core being able to survive given the buildings design drift, and secondly to determine the expected performance of hollow-core units that run parallel to walls, focusing on the alpha unit running by the wall. Fragility functions are created for a range of different parameters for both vertical dislocation and crack width that can be used as the basis of a quick analysis or loss estimation for the likely impact of hollow-core floors on building vulnerability and risk. This was done using past experimental tests, and the recorded damage. Using these results and the method developed by Baker fragility curves were able to be created for varying crack widths and vertical dislocations. Current guidelines for analysis of hollow-core unit incompatible displacements are based on experimental vertical displacement results from concrete moment resisting frame systems to determine the capacity of hollow-core elements. To investigate the demands on hollow-core units in a wall-based structure, a fibre-element model in the software Seismostruct is created and subject to quasi-static cyclic loading, using elements which are verified from previous experimental tests. It is shown that for hollow-core units running by walls that the 10 mm displacement capacity used for hollow-core units running by a beam is insufficient for members running by walls and that shear analysis should be used. The fibre-element model is used to simulate the seismic demand induced on the floor system and has shown that the shear demand is a function of drift, wall length, hollow-core span, linking slab length and, to a minor extent, wall elongation.
This thesis seeks to examine how the integration of play, small toys specifically, and the use of solution-focused brief therapy techniques can affect the outcomes for primary school aged children undergoing counselling. The setting is a counselling agency in Christchurch, New Zealand. A qualitative research approach is used and the data analysed using a narrative inquiry approach. The context of this study is the counselling service of an agency where young children, adolescents and their families are helped and supported through a variety of life issues. The counselling the participants are offered uses a combination of a solution-focused and play therapy where the purpose is to encourage clients to find exceptions to their presenting problems and identify their preferred future. The aim of this study is to help the children navigate their problem through a better understanding of and the gaining of personal skills and strengths. Participants were invited to be part of this study through the agency waiting list. The four included presented with a variety of reasons for coming to counselling yet these proved similar to that which the agency has been routinely presented with in the aftermath of the Canterbury earthquakes from 2011 to present day. Each participant had the consent of their parents or caregivers to engage in this project. The participants themselves separately agreed to engage in a solution- focused counselling process where the counsellor also integrated the use of small toys as part of the course. Counselling sessions were audiotaped, aspects photographed and analysed with a specific focus on client engagement. Four key themes emerged as the participants explored their personal narrative. Firstly, the “I’m OK” theme depicted in their first scaling activity, secondly a recognition that things could indeed be better and they needed help. Thirdly, a realisation of their own strengths and skills and finally that the future was an optimistic place to look forward to. These themes are described and explained through descriptions of the participant’s stories as well as self-reflection by the researcher. Transcriptions of sessions are included as are excerpts from the research journal and photographs of the use of the small toys by the children.
The Avon-Heathcote Estuary is of significant value to Christchurch due to its high productivity, biotic diversity, proximity to the city, and its cultural, recreational and aesthetic qualities. Nonetheless, it has been subjected to decades of degradation from sewage wastewater discharges and encroaching urban development. The result was a eutrophied estuary, high in nitrogen, affected by large blooms of nuisance macroalgae and covered by degraded sediments. In March 2010, treated wastewater was diverted from the estuary to a site 3 km offshore. This quickly reduced water nitrogen by 90% within the estuary and, within months, there was reduced production of macroalgae. However, a series of earthquakes beginning in September 2010 brought massive changes: tilting of the estuary, changes in channels and water flow, and a huge influx of liquefied sediments that covered up to 65% of the estuary floor. Water nitrogen increased due to damage to sewage infrastructure and the diversion pipeline being turned off. Together, these drastically altered the estuarine ecosystem. My study involves three laboratory and five in situ experiments that investigate the base of the food chain and responses of benthic microalgae to earthquake-driven sediment and nutrient changes. It was predicted that the new sediments would be coarser and less contaminated with organic matter and nutrients than the old sediments, would have decreased microalgal biomass, and would prevent invertebrate grazing and bioturbation activities. It was believed that microalgal biomass would become similar across new and old sediments types as the unstable new sediments were resuspended and distributed over the old sediments. Contact cores of the sediment were taken at three sites, across a eutrophication gradient, monthly from September 2011 to March 2012. Extracted chlorophyll a pigments showed that microalgal biomass was generally lower on new liquefied sediments compared to old sediments, although there was considerable site to site variation, with the highly eutrophic sites being the most affected by the emergence of the new sediments. Grazer experiments showed that invertebrates had both positive and negative site-specific effects on microalgal biomass depending on their identity. At one site, new sediments facilitated grazing by Amphibola crenata, whereas at another site, new sediments did not alter the direct and indirect effects of invertebrates (Nicon aestuariensis, Macropthalmus hirtipes, and A. crenata) on microalgae. From nutrient addition experiments it was clear that benthic microalgae were able to use nutrients from within both old and new sediments equally. This implied that microalgae were reducing legacy nutrients in both sediments, and that they are an important buffer against eutrophication. Therefore, in tandem with the wastewater diversion, they could underpin much of the recovery of the estuary. Overall, the new sediments were less favourable for benthic microalgal growth and recolonisation, but were less contaminated than old sediments at highly eutrophic sites. Because the new sediments were less contaminated than the old sediments, they could help return the estuary to a noneutrophic state. However, if the new sediments, which are less favourable for microalgal growth, disperse over the old sediments at highly eutrophic sites, they could become contaminated and interfere with estuarine recovery. Therefore, recovery of microalgal communities and the estuary was expected to be generally long, but variable and site-specific, with the least eutrophic sites recovering quickly, and the most eutrophic sites taking years to return to a pre-earthquake and non-eutrophied state. changes in channels and water flow, and a huge influx of liquefied sediments that covered up to 65% of the estuary floor. Water nitrogen increased due to damage to sewage infrastructure and the diversion pipeline being turned off. Together, these drastically altered the estuarine ecosystem. My study involves three laboratory and five in situ experiments that investigate the base of the food chain and responses of benthic microalgae to earthquake-driven sedimen tand nutrient changes. It was predicted that the new sediments would be coarser and less contaminated with organic matter and nutrients than the old sediments, would have decreased microalgal biomass, and would prevent invertebrate grazing and bioturbation activities. It was believed that microalgal biomass would become similar across new and old sediments types as the unstable new sediments were resuspended and distributed over the old sediments. Contact cores of the sediment were taken at three sites, across a eutrophication gradient, monthly from September 2011 to March 2012. Extracted chlorophyll a pigments showed that microalgal biomass was generally lower on new liquefied sediments compared to old sediments, although there was considerable site to site variation, with the highly eutrophic sites being the most affected by the emergence of the new sediments. Grazer experiments showed that invertebrates had both positive and negative site-specific effects on microalgal biomass depending on their identity. At one site, new sediments facilitated grazing by Amphibola crenata, whereas at another site, new sediments did not alter the direct and indirect effects of invertebrates (Nicon aestuariensis, Macropthalmus hirtipes, and A. crenata) on microalgae. From nutrient addition experiments it was clear that benthic microalgae were able to use nutrients from within both old and new sediments equally. This implied that microalgae were reducing legacy nutrients in both sediments, and that they are
Rising disaster losses, growth in global migration, migrant labour trends, and increasingly diverse populations have serious implications for disaster resilience around the world. These issues are of particular concern in New Zealand, which is highly exposed to disaster risk and has the highest proportion of migrant workers to national population in the OECD. Since there has been no research conducted into this issue in New Zealand to date, greater understanding of the social capital used by migrant workers in specific New Zealand contexts is needed to inform more targeted and inclusive disaster risk management approaches. A New Zealand case study is used to investigate the extent and types of social capital and levels of disaster risk awareness reported by members of three Filipino migrant workers organisations catering to dairy farm, construction and aged care workers in different urban and rural Canterbury districts. Findings from (3) semi-structured interviews and (3) focus groups include consistently high reliance on bonding capital and low levels of bridging capital across all three organisations and industry sectors, and in both urban and rural contexts. The transitory, precarious residential status conveyed by temporary work visas, and the difficulty of building bridging capital with host communities has contributed to this heavy reliance on bonding capital. Social media was essential to connect workers with family and friends in other countries, while Filipino migrant workers organisations provided members with valuable access to industry and district-specific networks of other Filipino migrant workers. Linking capital varied between the three organisations, with members of the organisation set up to advocate for dairy farm workers reporting the highest levels of linking capital. Factors influencing the capacity of workers organisations to develop linking capital appeared to include motivation (establishment objectives), length of time since establishment, support from government and industry groups, urban-rural context, income levels and gender. Although aware of publicity around earthquake and tsunami risk in the Canterbury region, participants were less aware of flood risk, and expressed fatalistic attitudes to disaster risk. Workers organisations offer a valuable potential interface between CDEM Group activities and migrant worker communities, since organisation leaders were interested in accessing government support to participate (with and on behalf of members) in disaster risk planning at district and regional level. With the potential to increase disaster resilience among these vulnerable, hard to reach communities, such participation could also help to build capacity across workers organisations (within Canterbury and across the country) to develop linking capital at national, as well as regional level. However, these links will also depend on greater government and industry commitment to providing more targeted and appropriate support for migrant workers, including consideration of the cultural qualifications of staff tasked with liaising with this community.
A number of reverse and strike-slip faults are distributed throughout mid-Canterbury, South Island, New Zealand, due to oblique continental collision. There is limited knowledge on fault interaction in the region, despite historical multi-fault earthquakes involving both reverse and strike-slip faults. The surface expression and paleoseismicity of these faults can provide insights into fault interaction and seismic hazards in the region. In this thesis, I studied the Lake Heron and Torlesse faults to better understand the key differences between these two adjacent faults located within different ‘tectonic domains’. Recent activity and surface expression of the Lake Heron fault was mapped and analysed using drone survey, Structure-from-Motion (SfM) derived Digital Surface Model (DSM), aerial image, 5 m-Digital Elevation Model (DEM), luminescence dating technique, and fold modelling. The results show a direct relationship between deformation zone width and the thickness of the gravel deposits in the area. Fold modelling using fault dip, net slip and gravel thickness produces a deformation zone comparable to the field, indicating that the fault geometry is sound and corroborating the results. This result Is consistent with global studies that demonstrate deposit (or soil thickness) correlates to fault deformation zone width, and therefore is important to consider for fault displacement hazard. A geomorphological study on the Torlesse fault was conducted using SfM-DSM, DEM and aerial images Ground Penetrating Radar (GPR) survey, trenching, and radiocarbon and luminescence dating. The results indicate that the Torlesse fault is primarily strike-slip with some dip slip component. In many places, the bedding-parallel Torlesse fault offsets post-glacial deposits, with some evidence of flexural slip faulting due to folding. Absolute dating of offset terraces using radiocarbon dating and slip on fault determined from lateral displacement calculating tool demonstrates the fault has a slip rate of around 0.5 mm/year to 1.0 mm/year. The likelihood of multi-fault rupture in the Torlesse Range has been characterised using paleoseismic trenching, a new structural model, and evaluation of existing paleoseismic data on the Porters Pass fault. Identification of overlapping of paleoseismic events in main Torlesse fault, flexural-slip faults and the Porters Pass fault in the Torlesse Range shows the possibility of distinct or multi-fault rupture on the Torlesse fault. The structural connectivity of the faults in the Torlesse zone forming a ‘flower structure’ supports the potential of multi-fault rupture. Multi-fault rupture modelling carried out in the area shows a high probability of rupture in the Porters Pass fault and Esk fault which also supports the co-rupture probability of faults in the region. This study offers a new understanding of the chronology, slip distribution, rupture characteristics and possible structural and kinematic relationship of Lake Heron fault and Torlesse fault in the South Island, New Zealand.
This dissertation explores the advocacy for the Christchurch Town Hall that occurred in 2012-2015 after the Canterbury Earthquakes. It frames this advocacy as an instance of collective-action community participation in a heritage decision, and explores the types of heritage values it expressed, particularly social values. The analysis contextualises the advocacy in post-quake Christchurch, and considers its relationship with other developments in local politics, heritage advocacy, and urban activism. In doing so, this dissertation considers how collective action operates as a form of public participation, and the practical implications for understanding and recognising social value. This research draws on studies of practices that underpin social value recognition in formal heritage management. Social value is held by communities outside institutions. Engaging with communities enables institutions to explore the values of specific places, and to realise the potential of activating local connections with heritage places. Such projects can be seen as participatory practices. However, these processes require skills and resources, and may not be appropriate for all places, communities and institutions. However, literature has understudied collective action as a form of community participation in heritage management. All participation processes have nuances of communities, processes, and context, and this dissertation analyses these in one case. The research specifically asked what heritage values (especially social values) were expressed through collective action, what the relationship was with the participation processes, communities, and wider situation that produced them, and the impact on institutional rhetoric and decisions. The research analysed values expressed in representations made to council in support of the Town Hall. It also used documentary sources and interviews with key informants to analyse the advocacy and decision-making processes and their relationships with the wider context and other grassroots activities. The analysis concluded that the values expressed intertwined social and professional values. They were related to the communities and circumstance that produced them, as an advocacy campaign for a civic heritage building from a Western architectural tradition. The advocacy value arguments were one of several factors that impacted the decision. They have had a lasting impact on rhetoric around the Town Hall, as was a heritage-making practice in its own right. This dissertation makes a number of contributions to the discussion of social value and community in heritage. It suggests connections between advocacy and participation perspectives in heritage. It recommends consideration of nuances of communities, context, and place meanings when using heritage advocacy campaigns as evidence of social value. It adds to the literature on heritage advocacy, and offers a focused analysis of one of many heritage debates that occurred in post-quake Christchurch. Ultimately, it encourages practice to actively integrate social and community values and to develop self-reflexive engagement and valuation processes. Despite inherent challenges, participatory processes offer opportunities to diversify understandings of value, co-produce heritage meanings with communities, and empower citizens in democratic processes around the places they live with and love.
Oblique-convergent plate collision between the Pacific and Australian plates across the South Island has resulted in shallow, upper crustal earthquake activity and ground surface deformation. In particular the Porters Pass - Amberley Fault Zone displays a complex hybrid zone of anastomosing dextral strike-slip and thrust/reverse faulting which includes the thrust/reverse Lees Valley Fault Zone and associated basin deformation. There is a knowledge gap with respect to the paleoseismicity of many of the faults in this region including the Lees Valley Fault Zone. This study aimed to investigate the earthquake history of the fault at a selected location and the structural and geomorphic development of the Lees Valley Fault Zone and eastern rangefront. This was investigated through extensive structural and geomorphic mapping, GPS field surveying, vertical aerial photo interpretation, analysis of Digital Elevation Models, paleoseismic trenching and optically stimulated luminescence dating. This thesis used a published model for tectonic geomorphology development of mountain rangefronts to understand the development of Lees Valley. Rangefront geomorphology is investigated through analysis of features such as rangefront sinuosity and faceted spurs and indicates the recently active and episodic nature of the uplifted rangefront. Analysis of fault discontinuity, fault splays, distribution of displacement, fault deformation zone and limited exposure of bedrock provided insight into the complex structure of the fault zone. These observations revealed preserved, earlier rangefronts, abandoned and uplifted within the eastern ranges, indicating a basinward shift in focus of faulting and an imbricate thrust wedge development propagating into the footwall of the fault zone and along the eastern ranges of Lees Valley. Fault scarp deformation analysis indicated multiple events have produced the deformation present preserved by the active fault trace in the northern valley. Vertical deformation along this scarp varied with a maximum of 11.5 m and an average of 5 m. Field mapping revealed fan surfaces of various ages have been offset and deformed, likely during the Holocene, based on expected relative surface ages. Geomorphic and structural mapping highlighted the effect of cross-cutting and inherited structures on the Lees Valley Fault, resulting in a step-over development in the centre of the eastern range-bounding trace. Paleoseismic trenching provided evidence of at least two earthquakes, which were constrained to post 21.6 ± 2.3 ka by optically stimulated luminescence dating. Single event displacements (1.48 ± 0.08 m), surface rupture earthquake magnitudes (Mw 6.7 ± 0.1, with potential to produce ≥ 7.0), and a minimum recurrence interval (3.6 ± 0.3 ka) indicated the Lees Valley Fault is an active structure capable of producing significant earthquake events. Results from this study indicate that the Lees Valley Fault Zone accommodates an important component of the Porters Pass - Amberley Fault Zone deformation and confirms the fault as a source of potentially damaging, peak ground accelerations in the Canterbury region. Remnants of previous rangefronts indicate a thrust wedge development of the Lees Valley Fault Zone and associated ranges that can potentially be used as a model of development for other thrust-fault bounded basins.
The Leader Fault was one of at least 17 faults that ruptured the ground surface across the northeastern South Island of New Zealand during the Mw 7.8 2016 Kaikōura Earthquake. The southern ~6 km of the Leader Fault, here referred to as the South Leader Fault (SLF), ruptured the North Canterbury (tectonic) Domain and is the primary focus of this study. The main objective of the thesis is to understand the key factors that contributed to the geometry and kinematics of the 2016 SLF rupture and its intersection with The Humps Fault (HF). This thesis employs a combination of techniques to achieve the primary objective, including detailed mapping of the bedrock geology, geomorphology and 2016 rupture, measurement of 2016 ground surface displacements, kinematic analysis of slip vectors from the earthquake, and logging of a single natural exposure across a 2016 rupture that was treated as a paleoseismic trench. The resulting datasets were collected in the field, from terrestrial LiDAR and InSAR imagery, and from historical (pre-earthquake) aerial photographs for a ~11 km2 study area. Surface ruptures in the study area are a miniature version of the entire rupture from the earthquake; they are geometrically and kinematically complex, with many individual and discontinuous segments of varying orientations and slip senses which are distributed across a zone up to ~3.5 km wide. Despite this variability, three main groups of ruptures have been identified. These are: 1) NE-SW striking, shallow to moderate dipping (25-45°W) faults that are approximately parallel to Cenozoic bedding with mainly reverse dip-slip and, and for the purposes of this thesis, are considered to be part of the SLF. 2) N-S striking, steeply dipping (~85°E) oblique sinistral faults that are up to the west and part of the SLF. 3) E-NE striking, moderate to steeply dipping (45-68°N) dextral reverse faults which are part of the HF. Bedding-parallel faults are interpreted to be flexural slip structures formed during folding of the near-surface Cenozoic strata, while the steeply dipping SLF ruptured a pre-existing bedrock fault which has little topographic expression. Groups 1 and 2 faults were both locally used for gravitational failure during the earthquake. Despite this non-tectonic fault movement, the slip vectors for faults that ruptured during the earthquake are broadly consistent with NCD tectonics and the regional ~100-120° trend of the principal horizontal stress/strain axes. Previous earthquake activity on the SLF is required by its displacement of Cenozoic formations but Late Quaternary slip on the fault prior to 2016 is neither supported by pre-existing fault scarps nor by changes in topography across the fault. By contrast, at least two earthquakes (including 2016) appear to have ruptured the HF from the mid Holocene, consistent with recurrence intervals of no more than ~7 kyr, and with preliminary observations from trenches on the fault farther to the west. The disparity in paleoearthquake records of the two faults suggests that they typically do not rupture together, thus it is concluded that the HF-SLF rupture pattern observed in the Kaikōura Earthquake rarely occurs in a single earthquake.
The Avon and Heathcote Rivers, located in the city of Christchurch, New Zealand, are lowland spring-fed rivers linked with the Christchurch Groundwater System. At present, the flow paths and recharge sources to the Christchurch Groundwater System are not fully understood. Study of both the Avon and Heathcote Rivers can provide greater insight into this system. In addition, during the period 2010-2012, Christchurch has experienced large amounts of seismic activity, including a devastating Mw 6.2 aftershock on February 22nd, 2011, which caused widespread damage and loss of life. Associated with these earthquakes was the release of large amounts of water through liquefaction and temporary springs throughout the city. This provided a unique opportunity to study groundwater surface water interactions following a large scale seismic event. Presented herein is the first major geochemical study on the Avon and Heathcote Rivers and the hydrological impact of the February 22, 2011 Christchurch Earthquake. The Avon, Heathcote, and Waimakariri Rivers were sampled in quarterly periods starting in July 2011 and analyzed for stable Isotopes δ¹⁸O, δD, and δ¹³C and major anion composition. In addition, post -earthquake samples were collected over the days immediately following the February 22, 2011 earthquake and analyzed for stable isotopes δ¹⁸O and δD and major anion composition. A variety of analytical methods were used identify the source of the waters in the Avon-Heathcote System and evaluate the effectiveness of stable isotopes as geochemical tracers in the Christchurch Groundwater System. The results of this thesis found that the waters from the Avon and Heathcote Rivers are geochemically the same, originating from groundwater, and exhibit a strong tidal influence within 5km of the Avon-Heathcote Estuary. The surface waters released following the February 22nd, 2011 earthquake were indistinguishable from quarterly samples taken from the Avon and Heathcote Rivers when comparing stable isotopic composition. The anion data suggests the waters released following the February 22nd, 2011 Christchurch Earthquake were sourced primarily from shallow groundwater, and also suggests a presence of urban sewage at some sites. Attempts to estimate recharge sources for the Avon-Heathcote Rivers using published models for the Christchurch Groundwater System yielded results that were not consistent between models. In evaluating the use of geochemical constituents as tracers in the Christchurch Groundwater System, no one isotope could provide a clear resolution, but when used in conjunction, δ¹⁸O, δ¹³C, and DIC, seem to be the most effective tracers. Sample sizes for δ¹³C were too small for a robust evaluation. Variability on the Waimakariri River appears to be greater than previously estimated, which could have significant impacts on geochemical models for the Christchurch Groundwater System. This research demonstrates the value of using multiple geochemical constituents to enrich our understanding of the groundwater surfaces-water interactions and the Christchurch Groundwater System as a whole.
Though generally considered “natural” disasters, cyclones and earthquakes are increasingly being associated with human activities, incubated through urban settlement patterns and the long-term redistribution of natural resources. As society is becoming more urbanized, the risk of human exposure to disasters is also rising. Architecture often reflects the state of society’s health: architectural damage is the first visible sign of emergency, and reconstruction is the final response in the process of recovery. An empirical assessment of architectural projects in post-disaster situations can lead to a deeper understanding of urban societies as they try to rebuild. This thesis offers an alternative perspective on urban disasters by looking at the actions and attitudes of disaster professionals through the lens of architecture, situated in recent events: the 2010 Christchurch earthquake, the 2010 Haiti earthquake, and the 2005 Hurricane Katrina. An empirical, multi-hazard, cross-sectional case study methodology was used, employing grounded theory method to build theory, and a critical constructivist strategy to inform the analysis. By taking an interdisciplinary approach to understanding disasters, this thesis positions architecture as a conduit between two divergent approaches to disaster research: the hazards approach, which studies the disaster cycles from a scientific perspective; and the sociological approach, which studies the socially constructed vulnerabilities that result from disasters, and the elements of social change that accompany such events. Few studies to date have attempted to integrate the multi-disciplinary perspectives that can advance our understanding of societal problems in urban disasters. To bridge this gap, this thesis develops what will be referred to as the “Rittelian framework”—based on the work of UC Berkeley’s architecture professor Horst Rittel (1930-1990). The Rittelian framework uses the language of design to transcend the multiple fields of human endeavor to address the “design problems” in disaster research. The processes by which societal problems are addressed following an urban disaster involve input by professionals from multiple fields—including economics, sociology, medicine, and engineering—but the contribution from architecture has been minimal to date. The main impetus for my doctoral thesis has been the assertion that most of the decisions related to reconstruction are made in the early emergency recovery stages where architects are not involved, but architects’ early contribution is vital to the long-term reconstruction of cities. This precipitated in the critical question: “How does the Rittelian framework contribute to the critical design decisions in modern urban disasters?” Comparative research was undertaken in three case studies of recent disasters in New Orleans (2005), Haiti (2010) and Christchurch (2010), by interviewing 51 individuals who were selected on the basis of employing the Rittelian framework in their humanitarian practice. Contextualizing natural disaster research within the robust methodological framework of architecture and the analytical processes of sociology is the basis for evaluating the research proposition that architectural problem solving is of value in addressing the ‘Wicked Problems’ of disasters. This thesis has found that (1) the nuances of the way disaster agents interpret the notion of “building back better” can influence the extent to which architectural professionals contribute in urban disaster recovery, (2) architectural design can be used to facilitate but also impede critical design decisions, and (3) framing disaster research in terms of design decisions can lead to innovation where least expected. This empirical research demonstrates how the Rittelian framework can inform a wider discussion about post-disaster human settlements, and improve our resilience through disaster research.
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.
