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Images for earthquake liquefaction; more images...

Research papers, University of Canterbury Library

At 00:02 on 14th November 2016, a Mw 7.8 earthquake occurred in and offshore of the northeast of the South Island of New Zealand. Fault rupture, ground shaking, liquefaction, and co-seismic landslides caused severe damage to distributed infrastructure, and particularly transportation networks; large segments of the country’s main highway, State Highway 1 (SH1), and the Main North Line (MNL) railway line, were damaged between Picton and Christchurch. The damage caused direct local impacts, including isolation of communities, and wider regional impacts, including disruption of supply chains. Adaptive measures have ensured immediate continued regional transport of goods and people. Air and sea transport increased quickly, both for emergency response and to ensure routine transport of goods. Road diversions have also allowed critical connections to remain operable. This effective response to regional transport challenges allowed Civil Defence Emergency Management to quickly prioritise access to isolated settlements, all of which had road access 23 days after the earthquake. However, 100 days after the earthquake, critical segments of SH1 and the MNL remain closed and their ongoing repairs are a serious national strategic, as well as local, concern. This paper presents the impacts on South Island transport infrastructure, and subsequent management through the emergency response and early recovery phases, during the first 100 days following the initial earthquake, and highlights lessons for transportation system resilience.

Research papers, University of Canterbury Library

At 00:02 on 14th November 2016, a Mw 7.8 earthquake occurred in and offshore of the northeast of the South Island of New Zealand. Fault rupture, ground shaking, liquefaction, and co-seismic landslides caused severe damage to distributed infrastructure, and particularly transportation networks; large segments of the country’s main highway, State Highway 1 (SH1), and the Main North Line (MNL) railway line, were damaged between Picton and Christchurch. The damage caused direct local impacts, including isolation of communities, and wider regional impacts, including disruption of supply chains. Adaptive measures have ensured immediate continued regional transport of goods and people. Air and sea transport increased quickly, both for emergency response and to ensure routine transport of goods. Road diversions have also allowed critical connections to remain operable. This effective response to regional transport challenges allowed Civil Defence Emergency Management to quickly prioritise access to isolated settlements, all of which had road access 23 days after the earthquake. However, 100 days after the earthquake, critical segments of SH1 and the MNL remain closed and their ongoing repairs are a serious national strategic, as well as local, concern. This paper presents the impacts on South Island transport infrastructure, and subsequent management through the emergency response and early recovery phases, during the first 100 days following the initial earthquake, and highlights lessons for transportation system resilience.

Research papers, The University of Auckland Library

Following the 2010/2011 Canterbury earthquakes a detailed campaign of door to door assessments was conducted in a variety of areas of Christchurch to establish the earthquake performance of residential dwellings having masonry veneer as an external cladding attached to a lightweight timber framing system. Specifically, care was taken to include regions of Christchurch which experienced different levels of earthquake shaking in order to allow comparison between the performance of different systems and different shaking intensities. At the time of the inspections the buildings in the Christchurch region had been repeatedly subjected to large earthquakes, presenting an opportunity for insight into the seismic performance of masonry veneer cladding. In total just under 1100 residential dwellings were inspected throughout the wider Christchurch area, of which 24% were constructed using the older nail-on veneer tie system (prior to 1996) and 76% were constructed using screw fixed ties to comply with the new 1996 standards revision (post-1996), with 30% of all inspected houses being of two storey construction. Of the inspected dwellings 27% had some evidence of liquefaction, ground settlement or lateral spreading. Data such as damage level, damage type, crack widths, level of repair required and other parameters were collected during the survey. A description of the data collection processes and a snapshot of the analysis results are presented within. http://15ibmac.com/home/

Images, UC QuakeStudies

Two images of a house, taken before and after the earthquakes. In the after photograph the chimneys are gone, a column supporting the car port has partly collapsed, windows are broken, and the previously neat lawn and driveway are overgrown. The photographer comments, "This was a house that I was selling up to the September 2010 earthquake in Christchurch. It was on Avonside Drive, which was an area that has been badly hit in every earthquake that has hit the area. In the September quake parts of the house moved in different directions and one of the upstairs doors had to be smashed open to release one of the sons from his bedroom. This occurred in the dark with numerous aftershocks shaking the house. Liquefaction poured up through the floor and flowed down the drive. Everyone got out OK, but soon after the house was red stickered meaning it was dangerous to enter. The house was looted many times even though there was constant police patrols. When the most violent earthquake occurred on 22 February 2012 both the tall heavy chimneys came crashing through into the living areas. Subsequent earthquakes and aftershocks have caused one of the brick fence pillars to fall and the front garage pillar to break up and twist. The family's troubles did not end there. They moved into the home of one of their parents and this mansion of a home was so badly affected by the February earthquake that no one could enter to collect any of their or their parents' belongings. They now own a new home, which they are fond of except when the ground shakes yet again. There has been to date 10,712 earthquakes and aftershocks since 4 September 2010".

Images, Alexander Turnbull Library

Text across the top of the cartoon reads 'You know you live in Christchurch when...' Six cameos follow reading 'You can stir a cup of coffee without a spoon' - a cup of coffee is shaken; 'after 30 years you finally know your neighbours' - a group of people get to know one another; 'the latest fitness craze is sandba' - a couple shovel a heap of liquefaction to music from their transistor; 'everyone gets to drive a slalom' - someone weaves along a road avoiding cracks and mud in their car; 'there's a craze in "unique garden features"' - a longdrop has been dug in the garden; and lastly 'you have tea under a doorframe' - a couple eats and drinks under a doorframe for safety. Context - the Christchurch earthquake of 22 February 2011. Published in The Press Quantity: 1 digital cartoon(s).

Research papers, University of Canterbury Library

Novel Gel-push sampling was employed to obtain high quality samples of Christchurch sands from the Central Business District, at sites where liquefaction was observed in 22 February 2011, and 13 June 2011 earthquakes. The results of cyclic triaxial testing on selected undisturbed specimens of typical Christchurch sands are presented and compared to empirical procedures used by practitioners. This comparison suggests cyclic triaxial data may be conservative, and the Magnitude Scaling Factor used in empirical procedures may be unconservative for highly compressible soils during near source moderate to low magnitude events. Comparison to empirical triggering curves suggests the empirical method generally estimates the cyclic strength of Christchurch sands within a reasonable degree of accuracy as a screening evaluation tool for liquefaction hazard, however for sands with moderate to high fines content it may be significantly unconservative, highlighting the need for high quality sampling and testing on important projects where seismic performance is critical.

Audio, Radio New Zealand

A 22-year-old self-employed dairy farmer hopes his success through winning a new Maori farming award will inspire other young troubled Maori to follow their dreams; The Chairperson of Nelson's first Maori language immersion school says there's been a shift in attitude among members of the public - who now understand the school won't be exclusive; The former National MP Sandra Goudie is calling for Waikato ratepayers to oppose two Maori seats that the Regional Council is introducing at next year's election; Liquefaction from the Christchurch earthquakes may have unearthed four taonga on the banks of the Heathcote river.

Audio, Radio New Zealand

The former National MP Sandra Goudie is calling for Waikato ratepayers to oppose two Maori seats that the Regional Council is introducing at next year's election; The Chairperson of Nelson's first Maori language immersion school says there's been a shift in attitude among members of the public - who now understand the school won't be exclusive; A 22-year-old self-employed dairy farmer hopes his success through winning a new Maori farming award will inspire other young troubled Maori to follow their dreams; Liquefaction from the Christchurch earthquakes may have unearthed four taonga on the banks of the Heathcote river.

Images, UC QuakeStudies

A car on Rowses Road has its entire front half embedded in liquefaction after falling into a sink hole. The photographer comments, "Perhaps the most impressively stuck car was this small silver hatchback that went head first into a large hole in a street just off Shortland Street (between Shortland and Breezes Road) in Aranui. The rear hatch was open when we came across it. Apparently there had been one person and a dog inside but they managed to escape. The silt has now settled around and inside the car, making the vehicle an intimidating monument to the earthquake".

Images, UC QuakeStudies

A car on Rowses Road has its entire front half embedded in liquefaction after falling into a sink hole. The photographer comments, "Perhaps the most impressively stuck car was this small silver hatchback that went head first into a large hole in a street just off Shortland Street (between Shortland and Breezes Road) in Aranui. The rear hatch was open when we came across it. Apparently there had been one person and a dog inside but they managed to escape. The silt has now settled around and inside the car, making the vehicle an intimidating monument to the earthquake".

Images, UC QuakeStudies

A car on Rowses Road has its entire front half embedded in liquefaction after falling into a sink hole. The photographer comments, "Perhaps the most impressively stuck car was this small silver hatchback that went head first into a large hole in a street just off Shortland Street (between Shortland and Breezes Road) in Aranui. The rear hatch was open when we came across it. Apparently there had been one person and a dog inside but they managed to escape. The silt has now settled around and inside the car, making the vehicle an intimidating monument to the earthquake".

Research papers, University of Canterbury Library

On 4 September 2010 the Magnitude 7.1 'Darfield' Earthquake marked the beginning of the Canterbury earthquake sequence. The Darfield earthquake produced strong ground shaking throughout the centralCanterbury Plains, affecting rural areas, small towns and the city of Christchurch. The event produced a 29km long surface rupture through intensive farmland, causing localised flooding and liquefaction. The central Canterbury plains were subjected to a sustained period of thousands of aftershocks in the months after the Darfield earthquake. The primary sector is a major component of the in New Zealand economy. Business units are predominantly small family-run farm organisations, though there are increasing levels of corporate farming. The agribusiness sector contributes 20 per cent of real GDP and 47 per cent of total exports for New Zealand. Of the approximately 2,000 farms that are located in the Canterbury Plains, the most common farming sectors in the region are Mixed farming (mostly comprised of sheep and/or beef farming), Dairy farming, and Arable farming (cropping). Many farms on the Canterbury Plains require some form of irrigation and are increasingly capital intensive, reliant on built infrastructure, technology and critical services. Farms are of great significance to their local rural economies, with many rural non-farming organisations dependent on the health of local farming organisations. Despite the economic significance of the sector, there have been few, if any studies analysing how modern intensive farms are affected by earthquakes. The aim of this report is to (1) summarise the impacts the Darfield earthquake had on farming organisations and outline in general terms how farms are vulnerable to the effects of an earthquake; (2) identify what factors helped mitigate earthquake-related impacts. Data for this paper was collected through two surveys of farming and rural non-farming organisations following the earthquake and contextual interviews with affected organisations. In total, 78 organisations participated in the study (Figure 1). Farming organisations represented 72% (N=56) of the sample.

Images, Alexander Turnbull Library

The title reads 'Ellerslie Flower Show to return to Christchurch...' Below are nine cameos showing 'sinking violets', 'cracked chrysanthemums', 'pooey perrenials', 'rubble roses', 'portaloo poppies', 'munted marigolds', 'knackered natives', the 'lily of liquefaction' and 'wearable exhibits' which shows a woman wearing a toilet roll and carrying a spade. Context: The next Ellerslie International Flower Show will be staged in North Hagley Park from 7-11 March 2012. Following cancellation of the 2011 Show after the 22 February earthquake, Christchurch City Council has confirmed that the citys premier garden show will go ahead next year in the same venue as previous years. (http://www.ellerslieflowershow.co.nz/) Quantity: 1 digital cartoon(s).

Research papers, University of Canterbury Library

Natural disasters are increasingly disruptive events that affect livelihoods, organisations, and economies worldwide. Research has identified the impacts and responses of organisations to different types of natural disasters, and have outlined factors, such as industry sector, that are important to organisational vulnerability and resilience. One of the most costly types of natural disasters in recent years has been earthquakes, and yet to date, the majority of studies have focussed on the effects of earthquakes in urban areas, while rural organisational impact studies have primarily focused on the effects of meteorological and climatic driven hazards. As a result, the likely impacts of an earthquake on rural organisations in a developed context is unconstrained in the literature. In countries like New Zealand, which have major earthquakes and agricultural sectors that are significant contributors to the economy, it is important to know what impacts an earthquake event would have on the rural industries, and how these impacts compare to that of a more commonly analysed, high-frequency event. In September of 2010, rural organisations in Canterbury experienced the 4 September 2010 Mw 7.1 `Darfield' earthquake and the associated aftershocks, which came to be known as the Canterbury earth- quake sequence. The earthquake sequence caused intense ground shaking, creating widespread critical service outages, structural and non-structural damage to built infrastructure, as well as ground surface damage from ooding, liquefaction and surface rupture. Concurrently on September 18 2010, rural organisations in Southland experienced an unseasonably late snowstorm and cold weather snap that brought prolonged sub-zero temperatures, high winds and freezing rain, damaging structures in the City of Invercargill and causing widespread livestock losses and production decreases across the region. This thesis documents the effects of the Canterbury earthquake sequence and Southland snowstorm on farming and rural non-farming organisations, utilizing comparable methodologies to analyse rural organisational impacts, responses and recovery strategies to natural disasters. From the results, a short- term impact assessment methodology is developed for multiple disasters. Additionally, a regional asset repair cost estimation model is proposed for farming organisations following a major earthquake event, and the use of social capital in rural organisational recovery strategies following natural disasters is analysed.

Images, UC QuakeStudies

Large cracks run through the brick cladding of this house in Wainoni. The photographer comments, "During the numerous earthquakes in Christchurch the land which ran alongside the Avon river on Avonside Drive slumped towards the waterway. Houses which were wooden framed and had an external brick veneer started to sink into the liquefied soil. This caused the brick walls to crack, but the houses' occupants though shook up were saved by the wooden framework from the houses collapsing on them".

Research papers, University of Canterbury Library

The magnitude Mw 6.2 earthquake of February 22nd 2011 that struck beneath the city of Christchurch, New Zealand, caused widespread damage and was particularly destructive to the Central Business District (CBD). The shaking caused major damage, including collapses of structures, and initiated ground failure in the form of soil liquefaction and consequent effects such as sand boils, surface flooding, large differential settlements of buildings and lateral spreading of ground towards rivers were observed. A research project underway at the University of Canterbury to characterise the engineering behaviour of the soils in the region was influenced by this event to focus on the performance of the highly variable ground conditions in the CBD. This paper outlines the methodology of this research to characterise the key soil horizons that underlie the CBD that influenced the performance of important structures during the recent earthquakes, and will influence the performance of the rebuilt city centre under future events. The methodology follows post-earthquake reconnaissance in the central city, a desk study on ground conditions, site selection, mobilisation of a post-earthquake ground investigation incorporating the cone penetration test (CPT), borehole drilling, shear wave velocity profiling and Gel-push sampling followed by a programme of laboratory testing including monotonic and cyclic testing of the soils obtained in the investigation. The research is timely and aims to inform the impending rebuild, with appropriate information on the soils response to dynamic loading, and the influence this has on the performance of structures with various foundation forms.

Images, UC QuakeStudies

A car on Rowses Road has its entire front half embedded in liquefaction after falling into a sink hole. Two other cars have their wheels stuck in the silt. The photographer comments, "Perhaps the most impressively stuck car was this small silver hatchback that went head first into a large hole in a street just off Shortland Street (between Shortland and Breezes Road) in Aranui. The rear hatch was open when we came across it. Apparently there had been one person and a dog inside but they managed to escape. The silt has now settled around and inside the car, making the vehicle an intimidating monument to the earthquake".

Images, UC QuakeStudies

A car on Rowses Road has its entire front half embedded in liquefaction after falling into a sink hole. Behind it, another car has its wheels stuck in the silt. The photographer comments, "Perhaps the most impressively stuck car was this small silver hatchback that went head first into a large hole in a street just off Shortland Street (between Shortland and Breezes Road) in Aranui. The rear hatch was open when we came across it. Apparently there had been one person and a dog inside but they managed to escape. The silt has now settled around and inside the car, making the vehicle an intimidating monument to the earthquake".

Images, UC QuakeStudies

A car on Rowses Road has its entire front half embedded in liquefaction after falling into a sink hole. Two other cars have their wheels stuck in the silt. The photographer comments, "Perhaps the most impressively stuck car was this small silver hatchback that went head first into a large hole in a street just off Shortland Street (between Shortland and Breezes Road) in Aranui. The rear hatch was open when we came across it. Apparently there had been one person and a dog inside but they managed to escape. The silt has now settled around and inside the car, making the vehicle an intimidating monument to the earthquake".

Images, UC QuakeStudies

A car on Rowses Road has its entire front half embedded in liquefaction after falling into a sink hole. Behind it, another car has its wheels stuck in the silt. The photographer comments, "Perhaps the most impressively stuck car was this small silver hatchback that went head first into a large hole in a street just off Shortland Street (between Shortland and Breezes Road) in Aranui. The rear hatch was open when we came across it. Apparently there had been one person and a dog inside but they managed to escape. The silt has now settled around and inside the car, making the vehicle an intimidating monument to the earthquake".

Images, UC QuakeStudies

A car on Rowses Road has its entire front half embedded in liquefaction after falling into a sink hole. Behind it, another car has its wheels stuck in the silt. The photographer comments, "Perhaps the most impressively stuck car was this small silver hatchback that went head first into a large hole in a street just off Shortland Street (between Shortland and Breezes Road) in Aranui. The rear hatch was open when we came across it. Apparently there had been one person and a dog inside but they managed to escape. The silt has now settled around and inside the car, making the vehicle an intimidating monument to the earthquake".

Images, Alexander Turnbull Library

The cartoon shows the leader of the new Mana Party, Hone Harawira, in four frames that illustrate 'The aftershock', 'the shake-up', 'the waiting & anxiety!...' and in the last frame 'the liquefaction...' as he sinks up to his chest in 'Poll Street'. Context - In fact Hone Harawira won the Te Tai Tokerau by-election with a majority of 1,117 votes, followed fairly closely by Kelvin Davis (Labour). The Labour and Mana candidates seemed to be neck and neck just before the election on 26 June 2011. The cartoon uses earthquake imagery to illustrate the emotional roller-coaster for Hone Harawira. Quantity: 1 digital cartoon(s).

Research papers, University of Canterbury Library

This manuscript provides a critical examination of the ground motions recorded in the near-source region resulting from the 22 February 2011 Christchurch earthquake. Particular attention is given to reconciling the observed spatial distribution of ground motions in terms of physical phenomena related to source, path and site effects. The large number of near-source observed strong ground motions show clear evidence of: forward-directivity, basin generated surface waves, liquefaction and other significant nonlinear site response. The pseudo-acceleration response spectra (SA) amplitudes and significant duration of strong motions agree well with empirical prediction models, except at long vibration periods where the influence of basin-generated surface waves and nonlinear site response are significant and not adequately accounted for in empirical SA models. Pseudo-acceleration response spectra are also compared with those observed in the 4 September 2010 Darfield earthquake and routine design response spectra used in order to emphasise the amplitude of ground shaking and elucidate the importance of local geotechnical characteristics on surface ground motions. The characteristics of the observed vertical component accelerations are shown to be strongly dependent on source-to-site distance and are comparable with those from the 4 September 2010 Darfield earthquake, implying the large amplitudes observed are simply a result of many observations at close distances rather than a peculiar source effect.

Images, UC QuakeStudies

A car on Rowses Road has its entire front half embedded in liquefaction after falling into a sink hole. Another car has its wheels stuck in the silt. In the foreground, a car drives through flooding which covers the road. The photographer comments, "Perhaps the most impressively stuck car was this small silver hatchback that went head first into a large hole in a street just off Shortland Street (between Shortland and Breezes Road) in Aranui. The rear hatch was open when we came across it. Apparently there had been one person and a dog inside but they managed to escape. The silt has now settled around and inside the car, making the vehicle an intimidating monument to the earthquake".

Images, UC QuakeStudies

A car on Rowses Road has its entire front half embedded in liquefaction after falling into a sink hole. Behind it, another car has its wheels stuck in the silt, and in the background a car drives through flooding. The photographer comments, "Perhaps the most impressively stuck car was this small silver hatchback that went head first into a large hole in a street just off Shortland Street (between Shortland and Breezes Road) in Aranui. The rear hatch was open when we came across it. Apparently there had been one person and a dog inside but they managed to escape. The silt has now settled around and inside the car, making the vehicle an intimidating monument to the earthquake".

Research papers, University of Canterbury Library

Liquefaction-induced lateral spreading during the 2011 Christchurch earthquake in New Zealand was severe and extensive, and data regarding the displacements associated with the lateral spreading provides an excellent opportunity to better understand the factors that influence these movements. Horizontal displacements measured from optical satellite imagery and subsurface data from the New Zealand Geotechnical Database (NZGD) were used to investigate four distinct lateral spread areas along the Avon River in Christchurch. These areas experienced displacements between 0.5 and 2 m, with the inland extent of displacement ranging from 100 m to over 600 m. Existing empirical and semi-empirical displacement models tend to under estimate displacements at some sites and over estimate at others. The integrated datasets indicate that the areas with more severe and spatially extensive displacements are associated with thicker and more laterally continuous deposits of liquefiable soil. In some areas, the inland extent of displacements is constrained by geologic boundaries and geomorphic features, as expressed by distinct topographic breaks. In other areas the extent of displacement is influenced by the continuity of liquefiable strata or by the presence of layers that may act as vertical seepage barriers. These observations demonstrate the need to integrate geologic/geomorphic analyses with geotechnical analyses when assessing the potential for lateral spreading movements.

Research papers, University of Canterbury Library

This report presents an overview of the soil profile characteristics at a number of strong motion station (SMS) sites in Christchurch and its surrounds. An extensive database of ground motion records has been captured by the SMS network in the Canterbury region during the Canterbury earthquake sequence. However in order to comprehensively understand the ground motions recorded at these sites and to be able to relate these motions to other locations, a detailed understanding of the shallow geotechnical profile at each SMS is required. The original NZS1170.5 (SNZ 2004) site subsoil classifications for each SMS site is based on regional geological information and well logs located at varying distances from the site. Given the variability of Christchurch soils, more detailed investigations are required in close vicinity to each SMS to better understand stratigraphy and soil properties, which are important in seismic site response. In this regard, CPT, SPT and borehole data, shear wave velocity (Vs) profiles, and horizontal to vertical spectral ratio measurements (H/V) in close vicinity to the SMS were used to develop representative soil profiles at each site. NZS1170.5 (SNZ 2004) site subsoil classifications were updated using Vs and SPT N60 criteria. Site class E boundaries were treated as a sliding scale rather than as a discrete boundary to account for locations with similar site effects potential, an approach which was shown to result in a better delineation between the site classes. SPT N60 values often indicate a stiffer site class than the Vs data for softer soil sites, highlighting the disparity between the two site investigation techniques. Both SPT N60 and Vs based site classes did not always agree with the original site classifications. This emphasises the importance of having detailed site‐specific information at SMS locations in order to properly classify them. Furthermore, additional studies are required to harmonize site classification based on SPT N60 and Vs. Liquefaction triggering assessments were carried out for the Darfield and Christchurch earthquakes, and compared against observed liquefaction surface manifestations and ground motions characteristics at each SMS. In general, the characteristics of the recorded ground motions at each site correlate well with the triggering analyses. However, at sites that likely liquefied at depth (as indicated by triggering analyses and/or inferred from the characteristics of the recorded surface acceleration time series), the presence of a non‐liquefiable crust layer at many of the SMS locations prevented the manifestation of any surface effects.

Research papers, University of Canterbury Library

The 2010 and 2011 earthquakes in the region of Canterbury, New Zealand caused widespread damage and the deaths of 185 people. Suburbs on the eastern side of Christchurch and in the satellite town of Kaiapoi, 20 kilometres north of Christchurch, were badly damaged by liquefaction. The Canterbury Earthquake Recovery Authority (CERA), a government organisation set up in the wake of the earthquakes, began to systematically zone all residential land in 2011. Based on the possibility for land remediation, 7860 houses in Christchurch and Kaiapoi were zoned red. Those who were in this zone were compensated and had to buy or build elsewhere. The other zone examined within this research – that of TC3 – lies within the green zone. Residents, in this zone, were able to stay in their houses but land was moderately damaged and required site-specific geotechnical investigations. This research sought to understand how residents’ senses of home were impacted by a disaster and the response efforts. Focusing on the TC3 and red zone of the eastern suburbs and the satellite town of Kaiapoi, this study interviewed 29 residents within these zones. The concept of home was explored with the respondents at three scales: home as a household; home as a community; and home as a city. There was a large amount of resistance to the zoning process and the handling of claims by insurance companies and the Earthquake Commission (EQC) after the earthquakes. Lack of transparency and communication, as well as extremely slow timelines were all documented as failings of these agencies. This research seeks to understand how participant’s sense of home changed on an individual level and how it was impacted by outside agencies. Homemaking techniques were also focused on showing that a changed sense of home will impact on how a person interacts with a space.

Research Papers, Lincoln University

Global biodiversity is threatened by human actions, including in urban areas. Urbanisation has removed and fragmented indigenous habitats. As one of the 25 biodiversity ’hot spots’, New Zealand is facing the problems of habitat loss and indigenous species extinction. In New Zealand cities, as a result of the land clearance and imported urban planning precepts, many urban areas have little or no original native forest remaining. Urbanisation has also been associated with the introduction of multitudes of species from around the world. Two large earthquakes shook Christchurch in 2010 and 2011 and caused a lot of damage. Parts of the city suffered from soil liquefaction after the earthquakes. In the most damaged parts of Christchurch, particularly in the east, whole neighbourhoods were abandoned and later demolished except for larger trees. Christchurch offers an excellent opportunity to study the biodiversity responses to an urban area with less intensive management, and to learn more about the conditions in urban environments that are most conducive to indigenous plant biodiversity. This study focuses on natural woody plant regeneration of forested sites in Christchurch city, many of which were also surveyed prior to the earthquakes. By repeating the pre-earthquake surveys, I am able to describe the natural regeneration occurring in Christchurch forested areas. By combining this with the regeneration that has occurred in the Residential Red Zone, successional trajectories can be described under a range of management scenarios. Using a comprehensive tree map of the Residential Red Zone, I was also able to document minimum dispersal distances of a range of indigenous trees in Christchurch. This is important for planning reserve connectivity. Moreover, I expand and improve on a previous analysis of the habitat connectivity of Christchurch (made before the earthquakes) to incorporate the Residential Red Zone, to assess the importance for habitat connectivity of restoring the indigenous forest in this area. In combination, these data sets are used to provide patch scenarios and some management options for biodiversity restoration in the Ōtākaro-Avon Red Zone post-earthquake.

Research papers, University of Canterbury Library

Asset management in power systems is exercised to improve network reliability to provide confidence and security for customers and asset owners. While there are well-established reliability metrics that are used to measure and manage business-as-usual disruptions, an increasing appreciation of the consequences of low-probability high-impact events means that resilience is increasingly being factored into asset management in order to provide robustness and redundancy to components and wider networks. This is particularly important for electricity systems, given that a range of other infrastructure lifelines depend upon their operation. The 2010-2011 Canterbury Earthquake Sequence provides valuable insights into electricity system criticality and resilience in the face of severe earthquake impacts. While above-ground assets are relatively easy to monitor and repair, underground assets such as cables emplaced across wide areas in the distribution network are difficult to monitor, identify faults on, and repair. This study has characterised in detail the impacts to buried electricity cables in Christchurch resulting from seismically-induced ground deformation caused primarily by liquefaction and lateral spread. Primary modes of failure include cable bending, stretching, insulation damage, joint braking and, being pulled off other equipment such as substation connections. Performance and repair data have been compiled into a detailed geospatial database, which in combination with spatial models of peak ground acceleration, peak ground velocity and ground deformation, will be used to establish rigorous relationships between seismicity and performance. These metrics will be used to inform asset owners of network performance in future earthquakes, further assess component criticality, and provide resilience metrics.