Social and natural capital are fundamental to people’s wellbeing, often within the context of local community. Developing communities and linking people together provide benefits in terms of mental well-being, physical activity and other associated health outcomes. The research presented here was carried out in Christchurch - Ōtautahi, New Zealand, a city currently re-building, after a series of devastating earthquakes in 2010 and 2011. Poor mental health has been shown to be a significant post-earthquake problem, and social connection has been postulated as part of a solution. By curating a disparate set of community services, activities and facilities, organised into a Geographic Information Systems (GIS) database, we created i) an accessibility analysis of 11 health and well-being services, ii) a mobility scenario analysis focusing on 4 general well-being services and iii) a location-allocation model focusing on 3 primary health care and welfare location optimisation. Our results demonstrate that overall, the majority of neighbourhoods in Christchurch benefit from a high level of accessibility to almost all the services; but with an urban-rural gradient (the further away from the centre, the less services are available, as is expected). The noticeable exception to this trend, is that the more deprived eastern suburbs have poorer accessibility, suggesting social inequity in accessibility. The findings presented here show the potential of optimisation modelling and database curation for urban and community facility planning purposes.
This thesis explores the discussions and perspectives of Christchurch secondary school students in regards to their particular experiences and engagement with Anzac. In this thesis I seek to rigorously and robustly examine these viewpoints through semi-structured focus group interviews and thematic analysis. I seek to situate these youth perspectives within wider debates around Anzac mythology and Anzac resurgence in New Zealand which often do not represent the youth outlook. These debates are seen, on the one hand, to present a resurgence of youth engagement with Anzac and, on the other hand, to present the idea that Anzac has become an exclusionary myth which distorts Australians’ and New Zealanders’ understanding of wider Anzac experiences and educates them in a narrow, militarised way. Youth engagement with Anzac was not something which could be solely situated under either of these debates and, instead, it was seen to be multifaceted and made up of unique ideas and elements. The youth in my study acknowledged that their Anzac education did have mythic elements which made it hard for them to engage with Anzac despite the fact that they were actually interested in learning and understanding it. These mythic elements were the idea that Anzac is taught as a ‘simple narrative’ which does not allow room for critique, that it emphasises a link between Anzac and national identity, that it disregards many alternative Anzac experiences and that it presents a particular New Zealand identity to internalise. These students responded to their mythic Anzac education in a very active way, and instead of accepting it as truth, they were able to have constructive and critical conversations about their education and push against parts of it which they found to be too narrow or skewed in particular directions based on gender, ethnicity and national identity. The students were not passive vessels which internalised their Anzac education as fact; instead, they were able to acknowledge the mythic elements of their education and its negative influence in the classroom. This thesis went further in exploring what factors were seen to enhance this active process of critique and provide students with alternative knowledge and perspectives about Anzac. These factors were ancestral ties to Anzac, research into personal Anzac stories and experiences, unassessed educational units, centenary discussions, an understanding of hardship through the earthquakes and alternative perspectives of the Anzac experience through access to the internet. These factors presented a broader understanding of Anzac perspectives and experiences and students believed that if the mythic elements of their education could be revised and these elements encouraged then their engagement with Anzac would continue long into the future.
During the 2010 - 2011 Canterbury earthquake sequence, extensive liquefaction was observed in many areas of Christchurch city and its surroundings, causing widespread damage to buildings and infrastructure. While existing simplified methods were found to work well in some areas of the city, there were also large areas where these methods did not perform satisfactorily. In some of these cases, researchers have proposed that layers of fine grained material within the soil profile may be responsible for preventing the manifestation of liquefaction. This paper presents preliminary findings on the mechanisms at play when pressure differentials exist across a clay layer. It is found that if the clay layer is unable to distort, then pore fluid is unable to break-through the layer even with relatively high pressures, resulting in dissipation of excess pore pressures by seepage. If the layers are however able to distort, then it is possible for the pore fluid to break through the clay layer, potentially resulting in adverse effects in terms of the severity of liquefaction.
In this thesis, focus is given to develop methodologies for rapidly estimating specific components of loss and downtime functions. The thesis proposes methodologies for deriving loss functions by (i) considering individual component performance; (ii) grouping them as per their performance characteristics; and (iii) applying them to similar building usage categories. The degree of variation in building stock and understanding their characteristics are important factors to be considered in the loss estimation methodology and the field surveys carried out to collect data add value to the study. To facilitate developing ‘downtime’ functions, this study investigates two key components of downtime: (i) time delay from post-event damage assessment of properties; and (ii) time delay in settling the insurance claims lodged. In these two areas, this research enables understanding of critical factors that influence certain aspects of downtime and suggests approaches to quantify those factors. By scrutinising the residential damage insurance claims data provided by the Earthquake Commission (EQC) for the 2010- 2011 Canterbury Earthquake Sequence (CES), this work provides insights into various processes of claims settlement, the time taken to complete them and the EQC loss contributions to building stock in Christchurch city and Canterbury region. The study has shown diligence in investigating the EQC insurance claim data obtained from the CES to get new insights and build confidence in the models developed and the results generated. The first stage of this research develops contribution functions (probabilistic relationships between the expected losses for a wide range of building components and the building’s maximum response) for common types of claddings used in New Zealand buildings combining the probabilistic density functions (developed using the quantity of claddings measured from Christchurch buildings), fragility functions (obtained from the published literature) and cost functions (developed based on inputs from builders) through Monte Carlo simulations. From the developed contribution functions, glazing, masonry veneer, monolithic and precast concrete cladding systems are found to incur 50% loss at inter-storey drift levels equal to 0.027, 0.003, 0.005 and 0.011, respectively. Further, the maximum expected cladding loss for glazing, masonry veneer, monolithic, precast concrete cladding systems are found to be 368.2, 331.9, 365.0, and 136.2 NZD per square meter of floor area, respectively. In the second stage of this research, a detailed cost breakdown of typical buildings designed and built for different purposes is conducted. The contributions of structural and non- structural components to the total building cost are compared for buildings of different usages, and based on the similar ratios of non-structural performance group costs to the structural performance group cost, four-building groups are identified; (i) Structural components dominant group: outdoor sports, stadiums, parkings and long-span warehouses, (ii) non- structural drift-sensitive components dominant group: houses, single-storey suburban buildings (all usages), theatres/halls, workshops and clubhouses, (iii) non-structural acceleration- sensitive components dominant group: hospitals, research labs, museums and retail/cold stores, and (iv) apartments, hotels, offices, industrials, indoor sports, classrooms, devotionals and aquariums. By statistically analysing the cost breakdowns, performance group weighting factors are proposed for structural, and acceleration-sensitive and drift-sensitive non-structural components for all four building groups. Thus proposed building usage groupings and corresponding weighting factors facilitate rapid seismic loss estimation of any type of building given the EDPs at storey levels are known. A model for the quantification of post-earthquake inspection duration is developed in the third stage of this research. Herein, phase durations for the three assessment phases (one rapid impact and two rapid building) are computed using the number of buildings needing inspections, the number of engineers involved in inspections and a phase duration coefficient (which considers the median building inspection time, efficiency of engineer and the number of engineers involved in each assessment teams). The proposed model can be used: (i) by national/regional authorities to decide the length of the emergency period following a major earthquake, and estimate the number of engineers required to conduct a post-earthquake inspection within the desired emergency period, and (ii) to quantify the delay due to inspection for the downtime modelling framework. The final stage of this research investigates the repair costs and insurance claim settlement time for damaged residential buildings in the 2010-2011 Canterbury earthquake sequence. Based on the EQC claim settlement process, claims are categorized into three groups; (i) Small Claims: claims less than NZD15,000 which were settled through cash payment, (ii) Medium Claims: claims less than NZD100,000 which were managed through Canterbury Home Repair Programme (CHRP), and (iii) Large Claims: claims above NZD100,000 which were managed by an insurance provider. The regional loss ratio (RLR) for greater Christchurch for three events inducing shakings of approximate seismic intensities 6, 7, and 8 are found to be 0.013, 0.066, and 0.171, respectively. Furthermore, the claim duration (time between an event and the claim lodgement date), assessment duration (time between the claim lodgement day and the most recent assessment day), and repair duration (time between the most recent assessment day and the repair completion day) for the insured residential buildings in the region affected by the Canterbury earthquake sequence is found to be in the range of 0.5-4 weeks, 1.5- 5 months, and 1-3 years, respectively. The results of this phase will provide useful information to earthquake engineering researchers working on seismic risk/loss and insurance modelling.
Mr Wayne Tobeck, Director of Southrim Group (SRG), sponsored this 2013 MEM Project titled; A Technical and Economic Feasibility Study for the Integration of GSHP Technology in the Christchurch Rebuild. Following the recent Christchurch earthquakes, a significant amount of land has become too unstable to support traditional building foundations. This creates an opportunity to implement new and unique foundation designs previously unconsidered due to high costs compared to traditional methods. One such design proposes that an Injection Micro-Piling technique could be used. This can also be coupled with HVAC technology to create a Ground Source Heat Pump (GSHP) arrangement in both new buildings and as retrofits for building requiring foundation repair. The purpose of this study was to complete a feasibility study on the merits of SRG pursuing this proposed product. A significant market for such a product was found to exist, while the product was also found to be technically and legally feasible. However, the proposed product was found to not be economically feasible with respect to Air Source Heat Pumps due to the significantly higher capital and installation costs required. Further analysis suggests GSHPs may become more economically attractive in operating temperatures lower than -9oC, though the existence of markets with this climate in NZ has not been studied. It is therefore suggested that SRG do not proceed with plans to develop a GSHP coupled foundation solution for the Christchurch rebuild.
Based on a qualitative study of four organisations involving 47 respondents following the extensive 2010 – 2011 earthquakes in Christchurch, New Zealand, this paper presents some guidance for human resource practitioners dealing with post-disaster recovery. A key issue is the need for the human resource function to reframe its practices in a post-disaster context, developing a specific focus on understanding and addressing changing employee needs, and monitoring the leadership behaviour of supervisors. This article highlights the importance of flexible organisational responses based around a set of key principles concerning communication and employee perceptions of company support.
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.
Coastal margins are exposed to rising sea levels that present challenging circumstances for natural resource management. This study investigates a rare example of tectonic displacement caused by earthquakes that generated rapid sea-level change in a tidal lagoon system typical of many worldwide. This thesis begins by evaluating the coastal squeeze effects caused by interactions between relative sea-level (RSL) rise and the built environment of Christchurch, New Zealand, and also examples of release from similar effects in areas of uplift where land reclamations were already present. Quantification of area gains and losses demonstrated the importance of natural lagoon expansion into areas of suitable elevation under conditions of RSL rise and showed that they may be necessary to offset coastal squeeze losses experienced elsewhere. Implications of these spatial effects include the need to provide accommodation space for natural ecosystems under RSL rise, yet other land-uses are likely to be present in the areas required. Consequently, the resilience of these environments depends on facilitating transitions between human land-uses either proactively or in response to disaster events. Principles illustrated by co-seismic sea-level change are generally applicable to climate change adaptation due to the similarity of inundation effects. Furthermore, they highlight the potential role of non-climatic factors in determining the overall trajectory of change. Chapter 2 quantifies impacts on riparian wetland ecosystems over an eight year period post- quake. Coastal wetlands were overwhelmed by RSL rise and recovery trajectories were surprisingly slow. Four risk factors were identified from the observed changes: 1) the encroachment of anthropogenic land-uses, 2) connectivity losses between areas of suitable elevation, 3) the disproportionate effect of larger wetland vulnerabilities, and 4) the need to protect new areas to address the future movement of ecosystems. Chapter 3 evaluates the unique context of shoreline management on a barrier sandspit under sea-level rise. A linked scenario approach was used to evaluate changes on the open coast and estuarine shorelines simultaneously and consider combined effects. The results show dune loss from a third of the study area using a sea-level rise scenario of 1 m over 100 years and with continuation of current land-uses. Increased exposure to natural hazards and accompanying demand for seawalls is a likely consequence unless natural alternatives can be progressed. In contrast, an example of managed retreat following earthquake-induced subsidence of the backshore presents a new opportunity to restart saltmarsh accretion processes seaward of coastal defences with the potential to reverse decades of degradation and build sea-level rise resilience. Considering both shorelines simultaneously highlights the existence of pinch-points from opposing forces that result in small land volumes above the tidal range. Societal adaptation is delicately poised between the paradigms of resisting or accommodating nature and challenged by the long perimeter and confined nature of the sandspit feature. The remaining chapters address the potential for salinity effects caused by tidal prism changes with a focus on the conservation of īnanga (Galaxias maculatus), a culturally important fish that supports New Zealand‘s whitebait fishery. Methodologies were developed to test the hypothesis that RSL changes would drive a shift in the distribution of spawning sites with implications for their management. Chapter 4 describes a new practical methodology for quantifying the total productivity and spatiotemporal variability of spawning sites at catchment scale. Chapter 5 describes the novel use of artificial habitats as a detection tools to help overcome field survey limitations in degraded environments where egg mortality can be high. The results showed that RSL changes resulted in major shifts in spawning locations and these were associated with new patterns of vulnerability due to the continuation of pre-disturbance land-uses. Unexpected findings includes an improved understanding of the spatial relationship between salinity and spawning habitat, and identification of an invasive plant species as important spawning habitat, both with practical management implications. To conclude, the design of legal protection mechanisms was evaluated in relation to the observed habitat shifts and with a focus on two new planning initiatives that identified relatively large protected areas (PAs) in the lower river corridors. Although the larger PAs were better able to accommodate the observed habitat shifts inefficiencies were also apparent due to spatial disparities between PA boundaries and the values requiring protection. To reduce unnecessary trade-offs with other land-uses, PAs of sufficient size to cover the observable spatiotemporal variability and coupled with adaptive capacity to address future change may offer a high effectiveness from a network of smaller PAs. The latter may be informed by both monitoring and modelling of future shifts and these are expected to include upstream habitat migration driven by the identified salinity relationships and eustatic sea-level rise. The thesis concludes with a summary of the knowledge gained from this research that can assist the development of a new paradigm of environmental sustainability incorporating conservation and climate change adaptation. Several promising directions for future research identified within this project are also discussed.
Advanced seismic effective-stress analysis is used to scrutinize the liquefaction performance of 55 well-documented case-history sites from Christchurch. The performance of these sites during the 2010-2011 Canterbury earthquake sequence varied significantly, from no liquefaction manifestation at the ground surface (in any of the major events) to severe liquefaction manifestation in multiple events. For the majority of the 55 sites, the simplified liquefaction evaluation procedures, which are conventionally used in engineering practice, could not explain these dramatic differences in the manifestation. Detailed geotechnical characterization and subsequent examination of the soil profile characteristics of the 55 sites identified some similarities but also important differences between sites that manifested liquefaction in the two major events of the sequence (YY-sites) and sites that did not manifest liquefaction in either event (NN-sites). In particular, while the YY-sites and NN-sites are shown to have practically identical critical layer characteristics, they have significant differences with regard to their deposit characteristics including the thickness and vertical continuity of their critical zones and liquefiable materials. A CPT-based effective stress analysis procedure is developed and implemented for the analyses of the 55 case history sites. Key features of this procedure are that, on the one hand, it can be fully automated in a programming environment and, on the other hand, it is directly equivalent (in the definition of cyclic resistance and required input data) to the CPT-based simplified liquefaction evaluation procedures. These features facilitate significantly the application of effective-stress analysis for simple 1D free-field soil-column problems and also provide a basis for rigorous comparisons of the outcomes of effective-stress analyses and simplified procedures. Input motions for the analyses are derived using selected (reference) recordings from the two major events of the 2010-2011 Canterbury earthquake sequence. A step-by-step procedure for the selection of representative reference motions for each site and their subsequent treatment (i.e. deconvolution and scaling) is presented. The focus of the proposed procedure is to address key aspects of spatial variability of ground motion in the near-source region of an earthquake including extended-source effects, path effects, and variation in the deeper regional geology.
In September 2010 and February 2011, the Canterbury region experienced devastating earthquakes with an estimated economic cost of over NZ$40 billion (Parker and Steenkamp, 2012; Timar et al., 2014; Potter et al., 2015). The insurance market played an important role in rebuilding the Canterbury region after the earthquakes. Homeowners, insurance and reinsurance markets and New Zealand government agencies faced a difficult task to manage the rebuild process. From an empirical and theoretic research viewpoint, the Christchurch disaster calls for an assessment of how the insurance market deals with such disasters in the future. Previous studies have investigated market responses to losses in global catastrophes by focusing on the insurance supply-side. This study investigates both demand-side and supply-side insurance market responses to the Christchurch earthquakes. Despite the fact that New Zealand is prone to seismic activities, there are scant previous studies in the area of earthquake insurance. This study does offer a unique opportunity to examine and document the New Zealand insurance market response to catastrophe risk, providing results critical for understanding market responses after major loss events in general. A review of previous studies shows higher premiums suppress demand, but how higher premiums and a higher probability of risk affect demand is still largely unknown. According to previous studies, the supply of disaster coverage is curtailed unless the market is subsidised, however, there is still unsettled discussion on why demand decreases with time from the previous disaster even when the supply of coverage is subsidised by the government. Natural disaster risks pose a set of challenges for insurance market players because of substantial ambiguity associated with the probability of such events occurring and high spatial correlation of catastrophe losses. Private insurance market inefficiencies due to high premiums and spatially concentrated risks calls for government intervention in the provision of natural disaster insurance to avert situations of noninsurance and underinsurance. Political economy considerations make it more likely for government support to be called for if many people are uninsured than if few people are uninsured. However, emergency assistance for property owners after catastrophe events can encourage most property owners to not buy insurance against natural disaster and develop adverse selection behaviour, generating larger future risks for homeowners and governments. On the demand-side, this study has developed an intertemporal model to examine how demand for insurance changes post-catastrophe, and how to model it theoretically. In this intertemporal model, insurance can be sought in two sequential periods of time, and at the second period, it is known whether or not a loss event happened in period one. The results show that period one demand for insurance increases relative to the standard single period model when the second period is taken into consideration, period two insurance demand is higher post-loss, higher than both the period one demand and the period two demand without a period one loss. To investigate policyholders experience from the demand-side perspective, a total of 1600 survey questionnaires were administered, and responses from 254 participants received representing a 16 percent response rate. Survey data was gathered from four institutions in Canterbury and is probably not representative of the entire population. The results of the survey show that the change from full replacement value policy to nominated replacement value policy is a key determinant of the direction of change in the level of insurance coverage after the earthquakes. The earthquakes also highlighted the plight of those who were underinsured, prompting policyholders to update their insurance coverage to reflect the estimated cost of re-building their property. The survey has added further evidence to the existing literature, such as those who have had a recent experience with disaster loss report increased risk perception if a similar event happens in future with females reporting a higher risk perception than males. Of the demographic variables, only gender has a relationship with changes in household cover. On the supply-side, this study has built a risk-based pricing model suitable to generate a competitive premium rate for natural disaster insurance cover. Using illustrative data from the Christchurch Red-zone suburbs, the model generates competitive premium rates for catastrophe risk. When the proposed model incorporates the new RMS high-definition New Zealand Earthquake Model, for example, insurers can find the model useful to identify losses at a granular level so as to calculate the competitive premium. This study observes that the key to the success of the New Zealand dual insurance system despite the high prevalence of catastrophe losses are; firstly the EQC’s flat-rate pricing structure keeps private insurance premiums affordable and very high nationwide homeowner take-up rates of natural disaster insurance. Secondly, private insurers and the EQC have an elaborate reinsurance arrangement in place. By efficiently transferring risk to the reinsurer, the cost of writing primary insurance is considerably reduced ultimately expanding primary insurance capacity and supply of insurance coverage.
The QuakeCoRE Emerging Researchers Chapter (QERC) is a network of students and emerging researchers composed of three chapters: Auckland, Canterbury, and Wellington. Our aim is to promote networking, collaboration, and knowledge sharing among emerging researchers in the earthquake resilience community. QERC does this by organising technical, social, and outreach events. As with everyone else during the pandemic crisis, QERC had to change its approach in organising events. However, instead of treating it as an obstacle, QERC utilised the lockdown period as an opportunity to connect the three chapters and organised more events than they usually would during normal times. In the 11 weeks that universities were closed and New Zealand was under Alert Levels 2, 3 and 4, QERC organised 15 various events such as research presentations, well-being workshops, a women's catch-up, and a trivia night. However, as the weeks went by, the novelty of online meetings faded and fewer people came to the virtual events. Therefore as soon as the country moved to Alert Level 1, the Chapters started organising in-person events, which members were eager to attend. Nonetheless, the option to join events remotely still remains and the three chapters continue to collaborate for various events.
Tsunami have the potential to cause significant disruptions to society, including damage to infrastructure, critical to the every-day operation of society. Effective risk management is required to reduce the potential tsunami impacts to them. Christchurch city, situated on the eastern coast of New Zealand’s South Island, is exposed to a number of far-field tsunami hazards. Although the tsunami hazard has been well identified for Christchurch city infrastructure, the likely impacts have not been well constrained. To support effective risk management a credible and realistic infrastructure impact model is required to inform risk management planning. The objectives of this thesis are to assess the impacts on Christchurch city infrastructure from a credible, hypothetical far-field tsunami scenario. To achieve this an impact assessment process is adopted, using tsunami hazard and exposure measures to determine asset vulnerability and subsequent impacts. However, the thesis identified a number of knowledge gaps in infrastructure vulnerability to tsunami. The thesis addresses this by using two approaches: a tsunami damage matrix; and the development of tsunami fragility functions. The tsunami damage matrix pools together tsunami impacts on infrastructure literature, and post-event field observations. It represents the most comprehensive ‘look-up’ resource for tsunami impacts to infrastructure to date. This damage matrix can inform the assessment of tsunami impacts on Christchurch city infrastructure by providing a measure of damage likelihood at various hazard intensities. A more robust approach to tsunami vulnerability of infrastructure are fragility functions, which are also developed in this thesis. These were based on post-event tsunami surveys of the 2011 ‘Tohoku’ earthquake tsunami in Japan. The fragility functions are limited to road and bridge infrastructure, but represent the highest resolution measure of vulnerability for the given assets. As well as providing a measure of damage likelihood for a given tsunami hazard intensity, these also indicate a level of asset damage. The impact assessment process, and synthesized vulnerability measures, are used to run tsunami impact models for Christchurch infrastructure to determine the probability of asset damage occurring and to determine if impact will reach or exceed a given damage state. The models suggest that infrastructure damage is likely to occur in areas exposed to tsunami inundation in this scenario, with significant damage identified for low elevation roads and bridges. The results are presented and discussed in the context of the risk management framework, with emphasis on using risk assessment to inform risk treatment, monitoring and review. In summary, this thesis A) advances tsunami vulnerability and impact assessment methodologies for infrastructure and B) provides a tsunami impact assessment framework for Christchurch city infrastructure which will inform infrastructure tsunami risk management for planners, emergency managers and lifelines groups.
The Porter's Pass-Amberley Fault Zone (PPAFZ) is a complex zone of anastomosing faults and folds bounding the south-eastern edge of the transition from subducting Pacific Plate to continental collision on the Australia Plate boundary. This study combines mapping of a 2000 km2 zone from the Southern Alps northeast to the coast near Amberley, 40 km north of metropolitan Christchurch, with an analysis of seismicity and a revision of regional seismic hazard. Three structural styles: 1) a western strike-slip, and 2) a more easterly thrust and reverse domain, pass into 3) a northwest verging fold belt on the northern Canterbury Plains, reflecting the structural levels exposed and the evolving west to east propagation. Basal remnants of a Late Cretaceous-Cenozoic, largely marine sedimentary cover sequence are preserved as outliers that unconformably overlie Mesozoic basement (greywacke and argillite of the Torlesse terrain) in the mountains of the PPAFZ and are underlain by a deeply leached zone which is widely preserved. Structure contouring of the unconformity surface indicates maximum, differential uplift of c.2600 m in the southwest, decreasing to c.1200 m in the coastal fold belt to the northeast. Much lower rates (or reversal) of uplift are evident a few kilometres southeast of the PPAFZ range-front escarpment. The youngest elements of the cover sequence are basement-derived conglomerates of Plio-Pleistocene age preserved on the SE margin. The source is more distant than the intervening mountains of the PPAFZ, probably from the Southern Alps, to the west and northwest. The absence of another regional unconformity on Mesozoic basement, older than Pleistocene, indicates that this uplift is post-Pliocene. Late Pleistocene(<100 kyr) differential uplift rates of c.0.5-2.7 m/kyr from uplifted marine terraces at the east coast, and rates of 2.5-3.3 m/kyr for tectonically-induced river-down cutting further west, suggest that uplift commenced locally during the last 1 Ma, and possibly within the last 0.5 Ma, if average rates are assumed to be uniform over time. Analysis of seismicity, recorded during a 10 week regional survey of micro earthquakes in 1990, identified two seismic zones beneath North Canterbury: 1) a sub-horizontal zone of activity restricted to the upper crust (≤12 km); and 2) a seismic zone in the lower crust (below a ceiling of ≤17 km), that broadens vertically to the north and northwest to a depth of c.40 km, with a bottom edge which dips 10°N and 15°NW, respectively. No events were recorded at depths between 12 km and 17 km, which is interpreted as a relatively aseismic, mid-crustal ductile layer. Marked differences (up to 60°) in the trend of strain axes for events above and below the inferred ductile layer are observed only north of the PPAFZ. A fundamental, north-to-south increase in the Wave-length of major geological structures occurs across the PPAFZ, and is interpreted as evidence that the upper crust beneath the Canterbury Plains is coupled to the lower crust, whereas the upper crust further north is not. Most of the recorded micro earthquakes <12 km deep beneath the PPAFZ have strike-slip mechanisms. It is probable that faults splay upward into the thrusts and folds at the surface as an evolving transpression zone in response to deep shear in basement. There have been no historic surface ruptures of the PPAFZ, but the zone has been characterised historically by frequent small earthquakes. Paleoseismic data (dated landslides and surface ruptures) compiled in this study, indicate a return period of 1500-1900 years between the last two M>7-7.5 earthquakes, and 500-700 years have elapsed since the last. The magnitudes of these events are estimated at c.M7.5, which represents a probable maximum magnitude for the PPAFZ. There are insufficient data to determine whether or not the frequency of large earthquakes conforms to a recognised model of behaviour, but comparison of the paleoseismic data with the historic record of smaller earthquakes, suggests that the magnitudes of the largest earthquakes in this zone are not exponentially distributed. A seismicity model for the PPAFZ (Elder et al., 1991) is reviewed, and a b-value of 1.0 is found to be consistent with the newly acquired paleoseismic data. This b-value reduces the predicted frequency of large earthquakes (M≥7.0) in this zone by a factor of 3.5, while retaining a conservative margin that allows for temporal variations in the frequency of large events and the possibility that the geological database is incomplete, suggesting grounds for revising the hazard model for Christchurch.
The Canterbury region of New Zealand experienced a sequence of strong earthquakes during 2010-2011. Responses included government acquisition of many thousands of residential properties in the city of Christchurch in areas with severe earthquake effects. A large and contiguous tract of this ‘red zoned’ land lies in close proximity to the Ōtākaro / Avon River and is known as the Avon-Ōtākaro Red Zone (AORZ). The focus of this study was to provide an overview of the floodplain characteristics of the AORZ and review of international experience in ecological restoration of similar river margin and floodplain ecosystems to extract restoration principles and associated learnings. Compared to pre-earthquake ground levels, the dominant trend in the AORZ is subsidence, together with lateral movement especially in the vicinity of waterway. An important consequence of land subsidence in the lower Ōtākaro / Avon River is greater exposure to flooding and the effects of sea level rise. Scenario modelling for sea level rise indicates that much of the AORZ is exposed to inundation within a 100 year planning horizon based on a 1 m sea level rise. As with decisions on built infrastructure, investments in nature-based ‘green infrastructure’ also require a sound business case including attention to risks posed by climate change. Future-proofing of the expected benefits of ecological restoration must therefore be secured by design. Understanding and managing the hydrology and floodplain dynamics are vital to the future of the AORZ. However, these characteristics are shared by other floodplain and river restoration projects worldwide. Identifying successful approaches provides a useful a source of useful information for floodplain planning in the AORZ. This report presents results from a comparative case study of three international examples to identify relevant principles for large-scale floodplain management at coastal lowland sites.
Designing a structure for higher- than-code seismic performance can result in significant economic and environmental benefits. This higher performance can be achieved using the principles of Performance-Based Design, in which engineers design structures to minimize the probabilistic lifecycle seismic impacts on a building. Although the concept of Performance-Based Design is not particularly new, the initial capital costs associated with designing structures for higher performance have historically hindered the widespread adoption of performance-based design practices. To overcome this roadblock, this research is focused on providing policy makers and stakeholders with evidence-based environmental incentives for designing structures in New Zealand for higher seismic performance. In the first phase of the research, the environmental impacts of demolitions in Christchurch following the Canterbury Earthquakes were quantified to demonstrate the environmental consequences of demolitions following seismic events. That is the focus here. A building data set consisting of 142 concrete buildings that were demolished following the earthquake was used to quantify the environmental impacts of the demolitions in terms of the embodied carbon and energy in the building materials. A reduced set of buildings was used to develop a material takeoff model to estimate material quantities in the entire building set, and a lifecycle assessment tool was used to calculate the embodied carbon and energy in the materials. The results revealed staggering impacts in terms of the embodied carbon and energy in the materials in the demolished buildings. Ongoing work is focused developing an environmental impact framework that incorporates all the complex factors (e.g. construction methodologies, repair methodologies (if applicable), demolition methodologies (if applicable), and waste management) that contribute to the environmental impacts of building repair and demolition following earthquakes.
Improving community resilience requires a way of thinking about the nature of a community. Two complementary aspects are proposed: the flows connecting the community with its surrounding environment and the resources the community needs for its ongoing life. The body of necessary resources is complex, with many interactions between its elements. A systems approach is required to understand the issues adequately. Community resilience is discussed in general terms together with strategies for improving it. The ideas are then illustrated and amplified by an extended case study addressing means of improving the resilience of a community on the West Coast of New Zealand to natural disasters. The case study is in two phases. The first relies on a mix of on-the-ground observations and constructed scenarios to provide recommendations for enhancing community resilience, while the second complements the first by developing a set of general lessons and issues to be addressed from observations of the Christchurch earthquakes of 2010 and 2011.
The majority of Christchurch’s stormwater has historically been discharged untreated directly into urban surface waterways. These receiving waterways have become adversely affected by the contaminants carried in the stormwater, particularly sediment and heavy metals. An event-based contaminant load model was developed to identify the distribution and magnitude of contaminant loads entering the waterway, as well as to assess the reduction in TSS and heavy metal loads that can be achieved by various stormwater management options. The GIS-Excel based model estimates contaminant loads from an individual storm event based on different contributing impervious surfaces and key rainfall characteristics (rainfall intensity, duration, pH and antecedent dry days). It then calculates contaminant reduction loads that could be achieved through source reduction (e.g. green roofs, repainting) as well as from treatment (e.g. raingardens, wet ponds) applied to different surfaces within the catchment. This model differs from other annual load models as it is event-based and accounts for storm characteristics in its calculation of contaminant loads. Christchurch is a valuable case setting due the unique opportunity for retrofitting improved stormwater management in the post-earthquake rebuild. It is anticipated that this modelling approach could later be adapted for use in other urban settings outside of Christchurch.
This thesis addresses the topic of local bond behaviour in RC structures. The mechanism of bond refers to the composite action between deformed steel reinforcing bars and the surrounding concrete. Bond behaviour is an open research topic with a wide scope, particularly because bond it is such a fundamental concept to structural engineers. However, despite many bond-related research findings having wide applications, the primary contribution of this research is an experimental evaluation of the prominent features of local bond behaviour and the associated implications for the seismic performance of RC structures. The findings presented in this thesis attempt to address some structural engineering recommendations made by the Canterbury Earthquakes Royal Commission following the 2010-2011 Canterbury (New Zealand) earthquake sequence. A chapter of this thesis discusses the structural behaviour of flexure-dominated RC wall structures with an insufficient quantity of longitudinal reinforcement, among other in situ conditions, that causes material damage to predominantly occur at a single crack plane. In this particular case, the extent of concrete damage and bond deterioration adjacent to the crack plane will influence the ductility capacity that is effectively provided by the reinforcing steel. As a consequence of these in situ conditions, some lightly reinforced wall buildings in Christchurch lost their structural integrity due to brittle fracture of the longitudinal reinforcement. With these concerning post-earthquake observations in mind, there is the underlying intention that this thesis presents experimental evidence of bond behaviour that allows structural engineers to re-assess their confidence levels for the ability of lightly reinforced concrete structures to achieve the life-safety seismic performance objective the ultimate limit state. Three chapters of this thesis are devoted to the experimental work that was conducted as the main contribution of this research. Critical details of the experimental design, bond testing method and test programme are reported. The bond stress-slip relationship was studied through 75 bond pull-out tests. In order to measure the maximum local bond strength, all bond tests were carried out on deformed reinforcing bars that did not yield as the embedded bond length was relatively short. Bond test results have been presented in two separate chapters in which 48 monotonic bond tests and 27 cyclic bond tests are presented. Permutations of the experiments include the loading rate, cyclic loading history, concrete strength (25 to 70 MPa), concrete age, cover thickness, bar diameter (16 and 20 mm), embedded length, and position of the embedded bond region within the specimen (close or far away to the free surface). The parametric study showed that the concrete strength significantly influences the maximum bond strength and that it is reasonable to normalise the bond stress by the square-root of the concrete compressive strength, √(f'c). The generalised monotonic bond behaviour is described within. An important outcome of the research is that the measured bond strength and stiffness was higher than stated by the bond stress-slip relationship in the fib Model Code 2010. To account for these observed differences, an alternative model is proposed for the local monotonic bond stress-slip relationship. Cyclic bond tests showed a significant proportion of the total bond degradation occurs after the loading cycle in the peak bond strength range, which is when bond slip has exceeded 0.5 mm. Subsequent loading to constant slip values showed a linear relationship between the amount of bond strength degradation and the log of the number of cycles that were applied. To a greater extent, the cyclic bond deterioration depends on the bond slip range, regardless of whether the applied load cycling is half- or fully-reversed. The observed bond deterioration and hysteretic energy dissipated during cyclic loading was found to agree reasonably well between these cyclic tests with different loading protocols. The cyclic bond deterioration was also found to be reasonably consistent exponential damage models found in the literature. This research concluded that the deformed reinforcing bars used in NZ construction, embedded in moderate to high strength concrete, are able to develop high local bond stresses that are mobilised by a small amount of local bond slip. Although the relative rib geometry was not varied within this experimental programme, a general conclusion of this thesis is that deformed bars currently available in NZ have a relative rib bearing area that is comparatively higher than the test bars used in previous international research. From the parametric study it was found that the maximum monotonic bond strength is significant enhanced by dynamic loading rates. Experimental evidence of high bond strength and initial bond stiffness generally suggests that only a small amount of local bond slip that can occur when the deformed test bar was subjected to large tension forces. Minimal bond slip and bond damage limits the effective yielding length that is available for the reinforcing steel to distribute inelastic material strains. Consequently, the potential for brittle fracture of the reinforcement may be a more problematic and widespread issue than is apparent to structural engineers. This research has provided information that improve the reliability of engineering predictions (with respect to ductility capacity) of maximum crack widths and the extent of bond deterioration that might occur in RC structures during seismic actions.
This study explored the experiences of 10 leaders in their intentional six-month implementation, during the 2010-2011Christchurch earthquakes, of an adapted positive leadership model. The study concluded that the combination of strategies in the model provided psychological and participative safety for leaders to learn and to apply new ways of working. Contrary to other studies on natural disaster, workplace performance increased and absenteeism decreased. The research contributes new knowledge to the positive leadership literature and new understanding, from the perspective of leaders, of the challenges of leading in a workplace environment of ongoing natural disaster events.
With origins in the South Bronx area of New York in the early 1970s, hip-hop culture is now produced and consumed globally. While hip-hop activities can be varied, hip-hop is generally considered to have four forms or “elements”: DJing, MCing, b-boying/b-girling, and graffiti. Although all four elements of hip-hop have become a part of many youth work initiatives across the globe, public debate and controversy continue to surround hip-hop activities. Very little research and literature has explored the complexities involved in the assembling of hip-hop activities in youth work sites of practice using these hip-hop elements. This study attends to the gap in hip-hop and human service literature by tracing how hip-hop activities were assembled in several sites of youth work activity in Christchurch, New Zealand. Actor-network theory (ANT) is the methodological framework used to map the assemblage of hip-hop-youth work activities in this study. ANT follows how action is distributed across both human and non-human actors. By recognising the potential agency of “things”, this research traces the roles played by human actors, such as young people and youth workers, together with those of non-human actors such as funding documents, social media, clothing, and youth venue equipment. This ethnographic study provides rich descriptions or “snapshots” of some of the key socio-material practices that shaped the enactment of hip-hop-youth work activities. These are derived from fieldwork undertaken between October 2009 and December 2011, where participant observation took place across a range of sites of hip-hop-youth work activity. In addition to this fieldwork, formal interviews were undertaken with 22 participants, the majority being youth workers, young people, and youth trust administrators. The ANT framework reveals the complexity of the task of assembling hip-hop in youth work worlds. The thesis traces the work undertaken by both human and non-human actors in generating youth engagement in hip-hop-youth work activities. Young people’s hip-hop interests are shown to be varied, multiple, and continually evolving. It is also shown how generating youth interest in hip-hop-youth work activities involved overcoming young people’s indifference or lack of awareness of the hip-hop resources a youth trust had on offer. Furthermore, the study highlights where hip-hop activities were edited or “tinkered” with to avoid hip-hop “bads”. The thesis also unpacks how needed resources were enlisted, and how funders’ interests were translated into supporting hip-hop groups and activities. By tracing the range of actors mobilised to enact hip-hop-youth work activities, this research reveals how some youth trusts could avoid having to rely on obtaining government funds for their hip-hop activities. The thesis also includes an examination of one youth trust’s efforts to reconfigure its hip-hop activities after the earthquakes that struck Christchurch city in 2010 and 2011. Working both in and on the world, the text that is this thesis is also understood as an intervention. This study constitutes a deliberate attempt to strengthen understandings of hip-hop as a complex, multiple, and fluid entity. It therefore challenges traditional media and literature representations that simplify and thus either stigmatise or celebrate hip-hop. As such, this study opens up possibilities to consider the opportunities, as well as the complexities of assembling hip-hop in youth work sites of practice.
This research attempts to understand whether community resilience and perceived livability are influenced by housing typologies in Christchurch, New Zealand. Using recent resident surveys undertaken by the Christchurch City Council, two indexes were created to reflect livability and community resilience. Indicators used to create both indexes included (1) enjoyment living in neighbourhood (2) satisfaction with local facilities (3) safety walking and (4) safety using public transport, (5) sense of community (6) neighbour interactions, (7) home ownership and (8) civic engagement. Scores were attributed to 72 neighbourhoods across Christchurch –and each neighbourhood was classified in one of the following housing typologies; (1) earthquake damaged, (2) relatively undamaged, (3) medium density and (4) greenfield developments. Spatial analysis of index scores and housing classifications suggest housing typologies do influence resident’s perceived livability and community bonds to an extent. It was found that deprivation also had a considerable influence on these indexes as well as residential stability. These additional influences help explain why neighbourhoods within the same housing classification differ in their index scores. Based on these results, several recommendations have been made to the CCC in relation to future research, urban development strategies and suburb specific renewal projects. Of chief importance, medium density neighbourhoods and deprived neighbourhoods require conscious efforts to foster community resilience. Results indicate that community resilience might be more important than livability in having a positive influence on the lived experience of residents. While thoughtful design and planning are important, this research suggests geospatial research tools could enable better community engagement outcomes and planning outcomes, and this could be interwoven into proactive and inclusive planning approaches like placemaking.
Surface rupture of the previously unrecognised Greendale Fault extended west-east for ~30 km across alluvial plains west of Christchurch, New Zealand, during the Mw 7.1 Darfield (Canterbury) earthquake of September 2010. Surface rupture displacement was predominantly dextral strike-slip, averaging ~2.5 m, with maxima of ~5 m. Vertical displacement was generally less than 0.75 m. The surface rupture deformation zone ranged in width from ~30 to 300 m, and comprised discrete shears, localised bulges and, primarily, horizontal dextral flexure. About a dozen buildings, mainly single-storey houses and farm sheds, were affected by surface rupture, but none collapsed, largely because most of the buildings were relatively flexible and resilient timber-framed structures and also because deformation was distributed over a relatively wide zone. There were, however, notable differences in the respective performances of the buildings. Houses with only lightly-reinforced concrete slab foundations suffered moderate to severe structural and non-structural damage. Three other buildings performed more favourably: one had a robust concrete slab foundation, another had a shallow-seated pile foundation that isolated ground deformation from the superstructure, and the third had a structural system that enabled the house to tilt and rotate as a rigid body. Roads, power lines, underground pipes, and fences were also deformed by surface fault rupture and suffered damage commensurate with the type of feature, its orientation to the fault, and the amount, sense and width of surface rupture deformation.
This paper presents a seismic velocity model of Canterbury, New Zealand based on 3D geologic surfaces and velocities from a range of data sources. The model provides the 3D crustal structure in the region at multiple length scales for seismic wave propagation simulations, such as broadband ground motion and shallow site response analyses related to understanding the ground motions and site responses during the 2010- 2011 Canterbury earthquakes. Pre-Quaternary geologic horizons are calculated based on the reinterpretation of a comprehensive network of seismic reflection surveys from seven different campaigns over the past 50 years, as well as point constraints across an array of petroleum industry drill holes. Particular attention is given to a detailed representation of Quaternary stratigraphy, representing shallow (z<250m) near-surface layers in the model. Seismic velocities are obtained from seismic reflection processing (for Vp) and also recently performed active and passive surface wave analyses (for Vs). Over 1,700 water wells in the region are used to constrain the complex inter-bedded Quaternary stratigraphy (gravels, sands, silts, organics etc.) near the coastline, including beneath urban Christchurch, which has resulted from fluvial deposition and marine regression and transgression. For the near-surface Springston and Christchurch Formations in the Christchurch urban area (z<50m), high-spatial resolution seismic velocities (including Vs30 ) were obtained from over 13,000 cone penetration tests combined with a recently developed CPT-Vs correlation.
This thesis examines the opportunities for young citizens in Christchurch to be engaged in city planning post-disaster. This qualitative study was conducted eight years after the 2010-2011 earthquakes and employed interviews with 18 young people aged between 12-24 years old, 14 of whom were already actively engaged in volunteering or participating in a youth council. It finds that despite having sought out opportunities for youth leadership and advocacy roles post-disaster, young people report frustration that they are excluded from decision-making and public life. These feelings of exclusion were described by young people as political, physical and social. Young people felt politically excluded from decision-making in the city, with some youth reporting that they did not feel listened to by decision-makers or able to make a difference. Physical exclusion was also experienced by the young people I interviewed, who reported that they felt excluded from their city and neighbourhood. This ranged from feeling unwelcome in certain parts of the city due to perceived social stratification, to actual exclusion from newly privatised areas in a post-quake recovery city. Social exclusion was reported by young people in the study in regard to their sense of marginalisation from the wider community, due to structural and social barriers. Among these, they observed a sense of prejudice towards them and other youth due to their age, class and/or ethnicity. The barriers to their participation and inclusion, and their aspirations for Christchurch post-disaster are discussed, as well as the implications of exclusion for young people’s wellbeing and sense of belonging. Results of this study contribute to the literature that challenges the sole focus on children and young peoples’ vulnerability post-disaster, reinforcing their capacity and desire to contribute to the recovery of their city and community (Peek, 2008). This research also challenges the narrative that young people are politically apathetic (Norris, 2004; Nissen, 2017), and adds to our understandings of the way that disasters can concentrate power amongst certain groups, in this case excluding young people generally from decision-making and public life. I conclude with some recommendations for a more robust post-disaster recovery in Christchurch, in ways that are more inclusive of young people and supportive of their wellbeing.
We present the initial findings from a study of adaptive resilience of lifelines organisations providing essential infrastructure services, in Christchurch, New Zealand following the earthquakes of 2010-2011. Qualitative empirical data was collected from 200 individuals in 11 organisations. Analysis using a grounded theory method identified four major factors that aid organisational response, recovery and renewal following major disruptive events. Our data suggest that quality of top and middle-level leadership, quality of external linkages, level of internal collaboration, ability to learn from experience, and staff well-being and engagement influence adaptive resilience. Our data also suggest that adaptive resilience is a process or capacity, not an outcome and that it is contextual. Post-disaster capacity/resources and post-disaster environment influence the nature of adaptive resilience.
Disasters are rare events with major consequences; yet comparatively little is known about managing employee needs in disaster situations. Based on case studies of four organisations following the devastating earthquakes of 2010 - 2011 in Christchurch, New Zealand, this paper presents a framework using redefined notions of employee needs and expectations, and charting the ways in which these influence organisational recovery and performance. Analysis of in-depth interview data from 47 respondents in four organisations highlighted the evolving nature of employee needs and the crucial role of middle management leadership in mitigating the effects of disasters. The findings have counterintuitive implications for human resource functions in a disaster, suggesting that organisational justice forms a central framework for managing organisational responses to support and engage employees for promoting business recovery.
Cultural heritage is a dynamic concept, incorporating the ideas and values of many different organisations and individuals; it is heavily dependent on the context of the item or site being conserved, and transforms something from an old article into a historically significant object. A formal definition of cultural heritage did not appear in the Antarctic Treaty System until 1995, however Antarctic heritage value has been applied to various sites and monuments since the inception of the Treaty, from Shackleton’s Nimrod Hut to a heavy tractor. This report examines a number of case studies to determine the various ways in which heritage items and sites can be managed – such as the removal of the South Pole Dome – as well as their conservation after natural disasters, for instance the Christchurch earthquakes.
Results from a series of 1D seismic effective stress analyses of natural soil deposits from Christchurch are summarized. The analysed soil columns include sites whose performance during the 2010-2011 Canterbury earthquakes varied significantly, from no liquefaction manifestation at the ground surface to very severe liquefaction, in which case a large area of the site was covered by thick soil ejecta. Key soil profile characteristics and response mechanisms affecting the severity of surface liquefaction manifestation and subsequent damage are explored. The influence of shaking intensity on the triggering and contribution of these mechanisms is also discussed. Careful examination of the results highlights the importance of considering the deposit as a whole, i.e. a system of layers, including interactions between layers in the dynamic response and through pore water pressure redistribution and water flow.
On 15 August 1868, a great earthquake struck off the coast of the Chile-Peru border generating a tsunami that travelled across the Pacific. Wharekauri-Rekohu-Chatham Islands, located 800 km east of Christchurch, Aotearoa-New Zealand (A-NZ) was one of the worst affected locations in A-NZ. Tsunami waves, including three over 6 metres high, injured and killed people, destroyed buildings and infrastructure, and impacted the environment, economy and communities. While experience of disasters, and advancements in disaster risk reduction systems and technology have all significantly advanced A-NZ’s capacity to be ready for and respond to future earthquakes and tsunami, social memory of this event and other tsunamis during our history has diminished. In 2018, a team of scientists, emergency managers and communication specialists collaborated to organise a memorial event on the Chatham Islands and co-ordinate a multi-agency media campaign to commemorate the 150th anniversary of the 1868 Arica tsunami. The purpose was to raise awareness of the disaster and to encourage preparedness for future tsunami. Press releases and science stories were distributed widely by different media outlets and many attended the memorial event indicating public interest for commemorating historical disasters. We highlight the importance of commemorating disaster anniversaries through memorial events, to raise awareness of historical disasters and increase community preparedness for future events – “lest we forget and let us learn.”
The question of whether forced relocation is beneficial or detrimental to the displaced households is a controversial and important policy question. After the 2011 earthquake in Christchurch, the government designated some of the worst affected areas as Residential Red Zones. Around 20,000 people were forced to move out of these Residential Red Zone areas, and were compensated for that. The objective of this paper is twofold. First, we aim to estimate the impact of relocation on the displaced households in terms of their income, employment, and their mental and physical health. Second, we evaluate whether the impact of relocation varies by the timing of to move, the destination (remaining within the Canterbury region or moving out of it) and demographic factors (gender, age, ethnicity). StatisticsNZ’s Integrated Data Infrastructure (IDI) from 2008 to 2017, which includes data on all households in Canterbury, and a difference-in-difference (DID) technique is used to answer these questions. We find that relocation has a negative impact on the income of the displaced household group. This adverse impact is more severe for later movers. Compared to the control group (that was not relocated), the income of relocated households was reduced by 3% for people who moved immediately after the earthquake in 2011, and 14% for people who moved much later in 2015.
