The city of Ōtautahi/Christchurch experienced a series of earthquakes that began on September 4th, 2010. The most damaging event occurred on February 22nd, 2011 but significant earthquakes also occurred on June 13th and December 23rd with aftershocks still occurring well into 2012. The resulting disaster is the second deadliest natural disaster in New Zealand’s history with 185 deaths. During 2011 the Canterbury earthquakes were one of the costliest disasters worldwide with an expected cost of up to $NZ30 billion. Hundreds of commercial buildings and thousands of houses have been destroyed or are to be demolished and extensive repairs are needed for infrastructure to over 100,000 homes. As many as 8,900 people simply abandoned their homes and left the city in the first few months after the February event (Newell, 2012), and as many as 50,000 may leave during 2012. In particular, young whānau and single young women comprised a disproportionate number of these migrants, with evidence of a general movement to the North Island. Te Puni Kōkiri sought a mix of quantitative and qualitative research to examine the social and economic impacts of the Christchurch earthquakes on Māori and their whānau. The result of this work will be a collection of evidence to inform policy to support and assist Māori and their whānau during the recovery/rebuild phases. To that end, this report triangulates available statistical and geographical information with qualitative data gathered over 2010 and 2011 by a series of interviews conducted with Māori who experienced the dramatic events associated with the earthquakes. A Māori research team at Lincoln University was commissioned to undertake the research as they were already engaged in transdisciplinary research (began in the May 2010), that focused on quickly gathering data from a range of Māori who experienced the disaster, including relevant economic, environmental, social and cultural factors in the response and recovery of Māori to these events. Participants for the qualitative research were drawn from Māori whānau who both stayed and left the city. Further data was available from ongoing projects and networks that the Lincoln research team was already involved in, including interviews with Māori first responders and managers operating in the CBD on the day of the February event. Some limited data is also available from younger members of affected whānau. Māori in Ōtautahi/Christchurch City have exhibited their own culturally-attuned collective responses to the disaster. However, it is difficult to ascertain Māori demographic changes due to a lack of robust statistical frameworks but Māori outward migration from the city is estimated to range between 560 and 1,100 people. The mobility displayed by Māori demonstrates an important but unquantified response by whānau to this disaster, with emigration to Australia presenting an attractive option for young Māori, an entrenched phenomenon that correlates to cyclical downturns and the long-term decline of the New Zealand economy. It is estimated that at least 315 Māori have emigrated from the Canterbury region to Australia post-quake, although the disaster itself may be only one of a series of events that has prompted such a decision. Māori children made up more than one in four of the net loss of children aged 6 to 15 years enrolled in schools in Greater Christchurch over the year to June 2011. Research literature identifies depression affecting a small but significant number of children one to two years post-disaster and points to increasing clinical and organisational demands for Māori and other residents of the city. For those residents in the eastern or coastal suburbs – home to many of the city’s Māori population - severe damage to housing, schools, shops, infrastructure, and streets has meant disruption to their lives, children’s schooling, employment, and community functioning. Ongoing abandonment of homes by many has meant a growing sense of unease and loss of security, exacerbated by arson, burglaries, increased drinking, a stalled local and national economy, and general confusion about the city’s future. Māori cultural resilience has enabled a considerable network of people, institutions, and resources being available to Māori , most noticeably through marae and their integral roles of housing, as a coordinating hub, and their arguing for the wider affected communities of Christchurch. Relevant disaster responses need to be discussed within whānau, kōhanga, kura, businesses, communities, and wider neighbourhoods. Comprehensive disaster management plans need to be drafted for all iwi in collaboration with central government, regional, and city or town councils. Overall, Māori are remarkably philosophical about the effects of the disaster, with many proudly relishing their roles in what is clearly a historic event of great significance to the city and country. Most believe that ‘being Māori’ has helped cope with the disaster, although for some this draws on a collective history of poverty and marginalisation, features that contribute to the vulnerability of Māori to such events. While the recovery and rebuild phases offer considerable options for Māori and iwi, with Ngāi Tahu set to play an important stakeholder in infrastructural, residential, and commercial developments, some risk and considerable unknowns are evident. Considerable numbers of Māori may migrate into the Canterbury region for employment in the rebuild, and trades training strategies have already been established. With many iwi now increasingly investing in property, the risks from significant earthquakes are now more transparent, not least to insurers and the reinsurance sector. Iwi authorities need to be appraised of insurance issues and ensure sufficient coverage exists and investments and developments are undertaken with a clear understanding of the risks from natural hazards and exposure to future disasters.
Lincoln University was commissioned by the Avon-Otakaro Network (AvON) to estimate the value of the benefits of a ‘recreation reserve’ or ‘river park’ in the Avon River Residential Red Zone (ARRRZ). This research has demonstrated significant public desire and support for the development of a recreation reserve in the Avon River Residential Red Zone. Support is strongest for a unique natural environment with native fauna and flora, healthy wetlands and rivers, and recreational opportunities that align with this vision, such as walking, cycling and water-based sporting and leisure activities. The research also showed support for a reserve that promotes and enables community interaction and wellbeing, and is evident in respondents’ desires for community gardens, regular festivals and markets, and the physical linking of the CBD with eastern suburbs through a green corridor. There is less support for children’s playgrounds, sports fields or open grassed areas, all of which could be considered as more typical of an urban park development. Benefits (willing to pay) to Christchurch residents (excluding tourists) of a recreation reserve could be as high as $35 million each year. Savings to public health costs could be as high as $50.3 million each year. The incorporation or restoration of various ecosystems services, including water quality improvements, flood mitigation and storm water management could yield a further $8.8 million ($19, 600) per hectare/year at 450 ha). Combined annual benefits of a recreational reserve in the ARRRZ are approximately $94.1 million per annum but this figure does not include potentially significant benefits from, for example, tourism, property equity gains in areas adjacent to the reserve, or the effects of economic rejuvenation in the East. Although we were not able to provide costing estimates for park attributes, this study does make available the value of benefits, which can be used as a guide to the scope of expenditure on development of each park attribute.
The 2010 and 2011 earthquakes of Canterbury have had a serious and ongoing effect on Maori in the city (Lambert, Mark-Shadbolt, Ataria, & Black, 2012). Many people had to rely on themselves, their neighbours and their whanau for an extended period in 2011, and some are still required to organise and coordinate various activities such as schooling, health care, work and community activities such as church, sports and recreation in a city beset by ongoing disruption and distress. Throughout the phases of response and recovery, issues of leadership have been implicitly and explicitly woven through both formal and informal investigations and debates. This paper presents the results of a small sample of initial interviews of Maori undertaken in the response and early recovery period of the disaster and discusses some of the implications for Maori urban communities.
The concept of geoparks was first introduced in the first international conference on geoparks held in China in 2004. Here in New Zealand, Kiwis are accustomed to national parks, land reserves, marine reserves, and urban cities and regional parks. The concept of these protected areas has been long-standing in the country, whereas the UNESCO concept of geoparks is still novel and yet to be established in New Zealand. In this dissertation, I explored the geopark concept for better understanding of its merits and examined the benefits of geotourism attractions as a sustainable economic development strategy to retrieve a declining rural economy. This research is focused on Kaikoura as a case study with geological significance, and emphasizes pre-earthquake existing geological heritages and new existing geological heritages post-earthquake to determine whether the geopark concept is appropriate and what planning framework is available to process this concept proposal should Kaikoura be interested in future.
From small coastal settlements to large cities, communities are exposed to both the direct and indirect consequences of climate-change induced sea-level rise (SLR). Above the ground surface, short- and long-term coastal effects of SLR are visible and cause damage from flooding, erosion, and loss of habitats and ecosystems. Below the ground surface, the effects are less visible but nonetheless extensive. Groundwater is present at shallow depth in the coastal zone and the effects of SLR on shallow groundwater threaten water security, agricultural production and infrastructure. Groundwater flooding, a hydrological hazard results from the process of water table rise, where the groundwater surface intersects or goes above the land surface due to changing conditions. The coastal zone is a complex dynamic space between saltwater and freshwater environments above and below the ground surface, and coastal groundwater hazards are intensified due to SLR. However, current monitoring of coastal shallow groundwater levels and salinity does not occur sufficiently to mitigate and adapt to the groundwater hazard. This thesis provides insights into the dynamics of coastal shallow groundwater, urban monitoring networks, simulations of water table rise and the issues posed by shallow groundwater changes driven by SLR and effects on flooding. The first study reviewed processes of coastal groundwater rise and simulation tools used to evaluate possible impacts of SLR. The benefits and limitations of the two main methods to assess coastal groundwater rise and its contribution to flooding - spatial interpolation and numerical tools - were discussed. The review highlighted the need for methodology comparisons between spatial interpolation and numerical tools to guide future work. The simulation tools that are used to evaluate changes in urban hydrogeology due to SLR do not specifically estimate groundwater flooding. Current monitoring practices do not capture evidence for groundwater rise with SLR. Therefore, the assessment methods need to rely on improved coastal groundwater monitoring networks focused on water quality, saltwater intrusion, and continuous groundwater levels records near the coastline, tidally influenced surface water bodies, and critical infrastructure. The second study focused on an urban shallow groundwater monitoring network and assessed its development, current physical condition and usefulness for SLR research. Following the 2010-2011 Canterbury Earthquake Sequence, in Otautahi Christchurch, ¯ Aotearoa New Zealand, shallow groundwater data acquisition and establishment of a geotechnical database provided unprecedented information on subsurface conditions. The monitoring infrastructure provided high spatio-temporal resolution records of shallow groundwater levels, which opened the field of New Zealand-based urban groundwater studies. Field surveys and digital information reviews showed that the monitoring net work was in overall good condition and robust, despite some maintenance issues. The dataset held by the city and regional councils should be more widely used to benefit the community, urban water management, researchers and practitioners, facing decisions to adapt and protect coastal areas from the impacts of climate change and SLR. The third study determined characteristics of shallow groundwater, including spatial and temporal trends in depths to groundwater and their relationship to natural and an thropogenic stressors. The study used depth to groundwater measurements from the uniquely extensive and densely spaced monitoring network in Otautahi Christchurch, ¯ Aotearoa New Zealand. Data-driven analysis approaches were applied, including spa tial interpolation, autocorrelation, clustering, cross-correlation, and trend analysis. This comprehensive approach revealed discernible clusters and trends within the dataset, pro viding valuable insights into the spatial and temporal variability of shallow groundwater in urban coastal settings. Responses to stresses such as rainfall events and stream flow were successfully classified using clustering analysis, while anthropogenic influences were more challenging. The primary feature in hydrograph classification proved to be the prox imity to tidal rivers and their correlation with tidal signals. This study highlighted the importance of monitoring coastal groundwater and the need for a better understanding of its effects on urban infrastructure and the built environment. The fourth study focused on simulating the effects of SLR on water table rise. These processes may lead to groundwater flooding and infrastructure challenges. A numerical model was used to assess the transient water table movement in response to SLR. Various SLR scenarios and rates were used to simulate the magnitudes and rates of water table rise, considering a range of aquifer parameters for both fixed-head and fixed-flux inland boundary conditions. The magnitudes and rates of water table rise were always less than but proportional to SLR and decreased with distance from the coastline. The magnitude and rate of water table rise in response to SLR were the largest for fixed flux inland boundary conditions, but it takes a long time for conditions to equilibrate. Fixed-flux conditions were found to pose a greater hazard as the maximum impact may not be experienced for decades, posing challenges to planners and managers of coastal groundwater systems. Adding a drain reduced the magnitude and rate of water table rise, more on the inland side than on the coastal side. The final study examined the key impacts of SLR on coastal shallow groundwater, and subsequent challenges faced by infrastructure asset managers. The study showed that current and future issues such as saltwater intrusion, flooding, and earthquake liquefaction hazard due to groundwater are exacerbated by climate change-driven SLR. A key issue is determining who will take responsibility for shallow groundwater management in areas with multiple and overlapping local government jurisdictions. Another key finding is that current techniques to manage groundwater in infrastructure construction/operation and land management will be applied in future, and challenges to coastal infrastructure adaptation will be posed by political and economic considerations rather than technical understanding.
Case study analysis of the 2010-2011 Canterbury Earthquake Sequence (CES), which particularly impacted Christchurch City, New Zealand, has highlighted the value of practical, standardised and coordinated post-earthquake geotechnical response guidelines for earthquake-induced landslides in urban areas. The 22nd February 2011 earthquake, the second largest magnitude event in the CES, initiated a series of rockfall, cliff collapse and loess failures around the Port Hills which severely impacted the south-eastern part of Christchurch. The extensive slope failure induced by the 22nd February 200 earthquake was unprecedented; and ground motions experienced significantly exceeded the probabilistic seismic hazard model for Canterbury. Earthquake-induced landslides initiated by the 22nd February 2011 earthquake posed risk to life safety, and caused widespread damage to dwellings and critical infrastructure. In the immediate aftermath of the 22nd February 2011 earthquake, the geotechnical community responded by deploying into the Port Hills to conduct assessment of slope failure hazards and life safety risk. Coordination within the voluntary geotechnical response group evolved rapidly within the first week post-earthquake. The lack of pre-event planning to guide coordinated geotechnical response hindered the execution of timely and transparent management of life safety risk from coseismic landslides in the initial week after the earthquake. Semi-structured interviews were conducted with municipal, management and operational organisations involved in the geotechnical response during the CES. Analysis of interview dialogue highlighted the temporal evolution of priorities and tasks during emergency response to coseismic slope failure, which was further developed into a phased conceptual model to inform future geotechnical response. Review of geotechnical responses to selected historical earthquakes (Northridge, 1994; Chi-Chi, 1999; Wenchuan, 2008) has enabled comparison between international practice and local response strategies, and has emphasised the value of pre-earthquake preparation, indicating the importance of integration of geotechnical response within national emergency management plans. Furthermore, analysis of the CES and international earthquakes has informed pragmatic recommendations for future response to coseismic slope failure. Recommendations for future response to earthquake-induced landslides presented in this thesis include: the integration of post-earthquake geotechnical response with national Civil Defence and Emergency Management; pre-earthquake development of an adaptive management structure and standard slope assessment format for geotechnical response; and emergency management training for geotechnical professionals. Post-earthquake response recommendations include the development of geographic sectors within the area impacted by coseismic slope failure, and the development of a GIS database for analysis and management of data collected during ground reconnaissance. Recommendations provided in this thesis aim to inform development of national guidelines for geotechnical response to earthquake-induced landslides in New Zealand, and prompt debate concerning international best 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.
As the future of the world’s oil reserves becomes progressively more uncertain, it is becoming increasingly important that steps are taken to ensure that there are viable, attractive alternatives to travel by private motor vehicle. As with many of New Zealand’s major urban centres, Christchurch is still exceptionally reliant on private motor vehicles; although a significant proportion of the population indicate that they would like to cycle more, cycling is still an underutilised mode of transport. Following a series of fatal earthquakes that struck the city in 2010 and 2011, there has been the need to significantly redevelop much of the city’s horizontal infrastructure – subsequently providing the perfect platform for significant changes to be made to the road network. Many of the key planning frameworks governing the rebuild process have identified the need to improve Christchurch’s cycling facilities in order to boost cycling numbers and cyclist safety. The importance of considering future growth and travel patterns when planning for transport infrastructure has been highlighted extensively throughout literature. Accordingly, this study sought to identify areas where future cycle infrastructure development would be advantageous based on a number of population and employment projections, and likely future travel patterns throughout the city. Through the use of extensive GIS analysis, future population growth, employment and travel patterns for Christchurch city were examined in order to attain an understanding of where the current proposed major cycleways network could be improved, or extended. A range of data and network analysis were used to derive likely travel patterns throughout Christchurch in 2041. Trips were derived twice, once with a focus on simply finding the shortest route between each origin and destination, and then again with a focus on cyclist safety and areas where cyclists were unlikely to travel. It was found that although the proposed major cycleways network represents a significant step towards improving the cycling environment in Christchurch, there are areas of the city that will not be well serviced by the current proposed network in 2041. These include a number of key residential growth areas such as Halswell, Belfast and Prestons, along with a number of noteworthy key travel zones, particularly in areas close to the central city and key employment areas. Using network analysis, areas where improvements or extensions to the proposed network would be most beneficial were identified, and a number of potential extensions in a variety of areas throughout the city were added to the network of cycle ways. Although it has been found that filling small gaps in the network can have considerable positive outcomes, results from the prioritisation analysis suggested that initially in Christchurch demand is likely to be for more substantial extensions to the proposed major cycleways network.
The Covid-19 pandemic has brought to the foreground the importance of social connectedness for wellbeing, at the individual, community and societal level. Within the context of the local community, pro-connection facilities are fundamental to foster community development, resilience and public health. Through identifying the gap in social connectedness literature for Māori, this has created space for new opportunities and to reflect on what is already occurring in Ōtautahi. It is well documented that Māori experience unequal societal impacts across all health outcomes. Therefore, narrowing the inequities between Māori and non-Māori across a spectrum of dimensions is a priority. Evaluating the #WellconnectedNZ project, which explores the intersections between social connection and wellbeing is one way to trigger these conversations. This was achieved by curating a dissimilar set of community pro-connection facilities and organizing them into a Geographic Information System (GIS). Which firstly involved, the collecting and processing of raw data, followed by spatial analysis through creating maps, this highlighted the alignment between the distribution of places, population and social data. Secondly, statistical analysis focusing on the relationship between deprivation and accessibility. Finally, semi-structured interviews providing perceptions of community experience. This study describes findings following a kaupapa Māori research approach. Results demonstrated that, in general some meshblocks in Ōtautahi benefit from a high level of accessibility to pro-connection facilities; but with an urban-rural gradient (as is expected, further from the central business district (CBD) are less facilities). Additionally, more-deprived meshblocks in the Southern and Eastern suburbs of Christchurch have poorer accessibility, suggesting underlying social and spatial inequalities, likely exacerbated by Covid-19 and the Christchurch earthquakes. In this context, it is timely to (re)consider pro-connection places and their role in the development of social infrastructure for connected communities, in the community facility planning space. ‘We are all interwoven, we just need to make better connections’.
A Line of Best Fit explores weakness and disconnection in the city. Weakness: There are over 600 earthquake prone buildings in Wellington. The urgency to strengthen buildings risks compromising the aesthetic integrity of the city through abrasive strengthening techniques, or losing a large portion of our built environment to demolition. The need for extensive earthquake strengthening in Wellington, Christchurch and other New Zealand cities provides an exciting opportunity for architecture. Disconnection: In Wellington pedestrian activity is focused around three main routes: Cuba Street, Lambton Quay and Courtney Place. The adjacent areas are often disconnected and lack vibrancy due to large building footprints, no-exit laneways and lack of public spaces. The Design proposes a strategy for earthquake strengthening, preserving and upgrading the built environment, and expanding and connecting the pedestrian realm. The site is two earthquake prone buildings on the block between Marion Street and Taranaki Street in central Wellington. A cut through the centre of the Aspro and Cathie Buildings ties the buildings together to strengthen and create a new arcade as public space. The cut aligns with existing pedestrian routes connecting the block with the city. The Design is divided into three components: Void, Curve, and Pattern and Structure. Void investigates the implications of cutting a portion out the existing buildings and the opportunities this provides for connection, urban interaction, and light. Curve discusses the unusual form of The Design in terms of scale, the human response and the surrounding spaces. Pattern and Structure considers the structural requirements of the project and how a void enveloped in perforated screens can strengthen the earthquake prone buildings. The importance of connection, providing strength in the city, a dialogue between old and new, and engagement with the unexpected are evaluated. Opportunities for further development and research are discussed, with particular reference to how the principles of The Design could be implemented on a larger scale throughout our cities. A Line of Best Fit is an architectural proposal that creates strength and connection.
The whare whakairo or traditional Māori meeting house plays an important part in Māori society and identity. These whare tell the tale of their origin, and in so doing, the origins of their people. The analysis of the meeting house, the histories expressed in its decorative carvings and structural elements are inextricably linked with and dependent upon the structure of the world created by myth and the Māori worldview. However, due to the deleterious effects of colonisation, the art of wood carving and associated architectural practices - central to Māori identity, suffered decline in many parts of the country, leading to the decline of Māori culture and identity. Sir Apirana Ngata instigated the National Institute of Māori Arts and Crafts to resurrect the dying art of Māori carving and carved houses would be a catalyst for the restoration of Māori culture throughout the country. Ngata saw these whare whakairo as being the heart of Māori communities by establishing a renewed sense of belonging and identification with space for Māori, through the telling of tribal histories and emphasising key geographical features. New threats in the form of global hegemony and urbanisation have further impacted on Māori notions of identity, creating a generation of displaced urban Māori youth. This research proposes to establish an architectural response to capture displaced Māori youth through the resurrection of the Māori carving school and return to them the lost stories of their cultural history and identity. This program will be developed within the complex challenges that exist within post-earthquake Ōtautahi/Christchurch, where many have lost homes and livelihoods, especially Māori youth in the Eastern Suburbs. The building elements of the proposed Māori carving school give reference to the historio-cultural features of the original Ōtautahi/Christchurch landscape that are situated in tribal song and myth. It is envisioned that the development of a Māori carving school will help restore Māori identity and a renewed sense of belonging, and allow for the telling of this generations stories through traditional narratives.
We present preliminary observations on three waters impacts from the Mw7.8 14th November 2016 Kaikōura Earthquake on wider metropolitan Wellington, urban and rural Marlborough, and in Kaikōura township. Three waters systems in these areas experienced widespread and significant transient ground deformation in response to seismic shaking, with localised permanent ground deformation via liquefaction and lateral spreading. In Wellington, potable water quality was impacted temporarily by increased turbidity, and significant water losses occurred due to damaged pipes at the port. The Seaview and Porirua wastewater treatment plants sustained damage to clarifier tanks from water seiching, and increased water infiltration to the wastewater system occurred. Most failure modes in urban Marlborough were similar to the 2010-2011 Canterbury Earthquake Sequence; however some rural water tanks experienced rotational and translational movements, highlighting importance of flexible pipe connections. In Kaikōura, damage to reservoirs and pipes led to loss of water supply and compromised firefighting capability. Wastewater damage led to environmental contamination, and necessitated restrictions on greywater entry into the system to minimise flows. Damage to these systems necessitated the importation of tankered and bottled water, boil water notices and chlorination of the system, and importation of portaloos and chemical toilets. Stormwater infrastructure such as road drainage channels was also damaged, which could compromise condition of underlying road materials. Good operational asset management practices (current and accurate information, renewals, appreciation of criticality, good system knowledge and practical contingency plans) helped improve system resilience, and having robust emergency management centres and accurate Geographic Information System data allowed effective response coordination. Minimal damage to the wider built environment facilitated system inspections. Note Future research will include detailed geospatial assessments of seismic demand on these systems and attendant modes of failure, levels of service restoration, and collaborative development of resilience measures.
The Canterbury earthquake sequence (2010-2011) was the most devastating catastrophe in New Zealand‘s modern history. Fortunately, in 2011 New Zealand had a high insurance penetration ratio, with more than 95% of residences being insured for these earthquakes. This dissertation sheds light on the functions of disaster insurance schemes and their role in economic recovery post-earthquakes. The first chapter describes the demand and supply for earthquake insurance and provides insights about different public-private partnership earthquake insurance schemes around the world. In the second chapter, we concentrate on three public earthquake insurance schemes in California, Japan, and New Zealand. The chapter examines what would have been the outcome had the system of insurance in Christchurch been different in the aftermath of the Canterbury earthquake sequence (CES). We focus on the California Earthquake Authority insurance program, and the Japanese Earthquake Reinsurance scheme. Overall, the aggregate cost of the earthquake to the New Zealand public insurer (the Earthquake Commission) was USD 6.2 billion. If a similar-sized disaster event had occurred in Japan and California, homeowners would have received only around USD 1.6 billion and USD 0.7 billion from the Japanese and Californian schemes, respectively. We further describe the spatial and distributive aspects of these scenarios and discuss some of the policy questions that emerge from this comparison. The third chapter measures the longer-term effect of the CES on the local economy, using night-time light intensity measured from space, and focus on the role of insurance payments for damaged residential property during the local recovery process. Uniquely for this event, more than 95% of residential housing units were covered by insurance and almost all incurred some damage. However, insurance payments were staggered over 5 years, enabling us to identify their local impact. We find that night-time luminosity can capture the process of recovery; and that insurance payments contributed significantly to the process of local economic recovery after the earthquake. Yet, delayed payments were less affective in assisting recovery and cash settlement of claims were more effective than insurance-managed repairs. After the Christchurch earthquakes, the government declared about 8000 houses as Red Zoned, prohibiting further developments in these properties, and offering the owners to buy them out. The government provided two options for owners: the first was full payment for both land and dwelling at the 2007 property evaluation, the second was payment for land, and the rest to be paid by the owner‘s insurance. Most people chose the second option. Using data from LINZ combined with data from Stats NZ, the fourth chapter empirically investigates what led people to choose this second option, and how peer effect influenced the homeowners‘ choices. Due to climate change, public disclosure of coastal hazard information through maps and property reports have been used more frequently by local government. This is expected to raise awareness about disaster risks in local community and help potential property owners to make informed locational decision. However, media outlets and business sector argue that public hazard disclosure will cause a negative effect on property value. Despite this opposition, some district councils in New Zealand have attempted to implement improved disclosure. Kapiti Coast district in the Wellington region serves as a case study for this research. In the fifth chapter, we utilize the residential property sale data and coastal hazard maps from the local district council. This study employs a difference-in-difference hedonic property price approach to examine the effect of hazard disclosure on coastal property values. We also apply spatial hedonic regression methods, controlling for coastal amenities, as our robustness check. Our findings suggest that hazard designation has a statistically and economically insignificant impact on property values. Overall, the risk perception about coastal hazards should be more emphasized in communities.
Territorial authorities in New Zealand are responding to regulatory and market forces in the wake of the 2011 Christchurch earthquake to assess and retrofit buildings determined to be particularly vulnerable to earthquakes. Pending legislation may shorten the permissible timeframes on such seismic improvement programmes, but Auckland Council’s Property Department is already engaging in a proactive effort to assess its portfolio of approximately 3500 buildings, prioritise these assets for retrofit, and forecast construction costs for improvements. Within the programme structure, the following varied and often competing factors must be accommodated: * The council’s legal, fiscal, and ethical obligations to the people of Auckland per building regulations, health and safety protocols, and economic growth and urban development planning strategies; * The council’s functional priorities for service delivery; * Varied and numerous stakeholders across the largest territorial region in New Zealand in both population and landmass; * Heritage preservation and community and cultural values; and * Auckland’s prominent economic role in New Zealand’s economy which requires Auckland’s continued economic production post-disaster. Identifying those buildings most at risk to an earthquake in such a large and varied portfolio has warranted a rapid field assessment programme supplemented by strategically chosen detailed assessments. Furthermore, Auckland Council will benefit greatly in time and resources by choosing retrofit solutions, techniques, and technologies applicable to a large number of buildings with similar configurations and materials. From a research perspective, the number and variety of buildings within the council’s property portfolio will provide valuable data for risk modellers on building typologies in Auckland, which are expected to be fairly representative of the New Zealand building stock as a whole
This paper presents the preliminary conclusions of the first stage of Wellington Case Study project (Regulating For Resilience in an Earthquake Vulnerable City) being undertaken by the Disaster Law Research Group at the University of Canterbury Law School. This research aims to map the current regulatory environment around improving the seismic resilience of the urban built environment. This work provides the basis for the second stage of the project which will map the regulatory tools onto the reality of the current building stock in Wellington. Using a socio-legal methodology, the current research examines the regulatory framework around seismic resilience for existing buildings in New Zealand, with a particularly focus on multi-storey in the Wellington CBD. The work focusses both on the operation and impact of the formal seismic regulatory tools open to public regulators (under the amended Building Act) as other non-seismic regulatory tools. As well as examining the formal regulatory frame, the work also provides an assessment of the interactions between other non-building acts (such as Health and Safety at Work Act 2015) on the requirements of seismic resilience. Other soft-law developments (particularly around informal building standards) are also examined. The final output of this work will presents this regulatory map in a clear and easily accessible manner and provide an assessment of the suitability of this at times confusing and patchy legal environment as Wellington moves towards becoming a resilient city. The final conclusion of this work will be used to specifically examine the ability of Wellington to make this transition under the current regulatory environment as phase two of the Wellington Case Study project.
Christchurch City Council (Council) is undertaking the Land Drainage Recovery Programme in order to assess the effects of the earthquakes on flood risk to Christchurch. In the course of these investigations it has become better understood that floodplain management should be considered in a multi natural hazards context. Council have therefore engaged the Jacobs, Beca, University of Canterbury, and HR Wallingford project team to investigate the multihazards in eastern areas of Christchurch and develop flood management options which also consider other natural hazards in that context (i.e. how other hazards contribute to flooding both through temporal and spatial coincidence). The study has three stages: Stage 1 Gap Analysis – assessment of information known, identification of gaps and studies required to fill the gaps. Stage 2 Hazard Studies – a gap filling stage with the studies identified in Stage 1. Stage 3 Collating, Optioneering and Reporting – development of options to manage flood risk. This present report is to document findings of Stage 1 and recommends the studies that should be completed for Stage 2. It has also been important to consider how Stage 3 would be delivered and the gaps are prioritised to provide for this. The level of information available and hazards to consider is extensive; requiring this report to be made up of five parts each identifying individual gaps. A process of identifying information for individual hazards in Christchurch has been undertaken and documented (Part 1) followed by assessing the spatial co-location (Part 2) and probabilistic presence of multi hazards using available information. Part 3 considers multi hazard presence both as a temporal coincidence (e.g. an earthquake and flood occurring at one time) and as a cascade sequence (e.g. earthquake followed by a flood at some point in the future). Council have already undertaken a number of options studies for managing flood risk and these are documented in Part 4. Finally Part 5 provides the Gap Analysis Summary and Recommendations to Council. The key findings of Stage 1 gap analysis are: - The spatial analysis showed eastern Christchurch has a large number of hazards present with only 20% of the study area not being affected by any of the hazards mapped. Over 20% of the study area is exposed to four or more hazards at the frequencies and data available. - The majority of the Residential Red Zone is strongly exposed to multiple hazards, with 86% of the area being exposed to 4 or more hazards, and 24% being exposed to 6 or more hazards. - A wide number of gaps are present; however, prioritisation needs to consider the level of benefit and risks associated with not undertaking the studies. In light of this 10 studies ranging in scale are recommended to be done for the project team to complete the present scope of Stage 3. - Stage 3 will need to consider a number of engineering options to address hazards and compare with policy options; however, Council have not established a consistent policy on managed retreat that can be applied for equal comparison; without which substantial assumptions are required. We recommend Council undertake a study to define a managed retreat framework as an option for the city. - In undertaking Stage 1 with floodplain management as the focal point in a multi hazards context we have identified that Stage 3 requires consideration of options in the context of economics, implementation and residual risk. Presently the scope of work will provide a level of definition for floodplain options; however, this will not be at equal levels of detail for other hazard management options. Therefore, we recommend Council considers undertaking other studies with those key hazards (e.g. Coastal Hazards) as a focal point and identifies the engineering options to address such hazards. Doing so will provide equal levels of information for Council to make an informed and defendable decision on which options are progressed following Stage 3.
Natural hazard disasters often have large area-wide impacts, which can cause adverse stress-related mental health outcomes in exposed populations. As a result, increased treatment-seeking may be observed, which puts a strain on the limited public health care resources particularly in the aftermath of a disaster. It is therefore important for public health care planners to know whom to target, but also where and when to initiate intervention programs that promote emotional wellbeing and prevent the development of mental disorders after catastrophic events. A large body of literature assesses factors that predict and mitigate disaster-related mental disorders at various time periods, but the spatial component has rarely been investigated in disaster mental health research. This thesis uses spatial and spatio-temporal analysis techniques to examine when and where higher and lower than expected mood and anxiety symptom treatments occurred in the severely affected Christchurch urban area (New Zealand) after the 2010/11 Canterbury earthquakes. High-risk groups are identified and a possible relationship between exposure to the earthquakes and their physical impacts and mood and anxiety symptom treatments is assessed. The main research aim is to test the hypothesis that more severely affected Christchurch residents were more likely to show mood and anxiety symptoms when seeking treatment than less affected ones, in essence, testing for a dose-response relationship. The data consisted of mood and anxiety symptom treatment information from the New Zealand Ministry of Health’s administrative databases and demographic information from the National Health Index (NHI) register, when combined built a unique and rich source for identifying publically funded stress-related treatments for mood and anxiety symptoms in almost the whole population of the study area. The Christchurch urban area within the Christchurch City Council (CCC) boundary was the area of interest in which spatial variations in these treatments were assessed. Spatial and spatio-temporal analyses were done by applying retrospective space-time and spatial variation in temporal trends analysis using SaTScan™ software, and Bayesian hierarchical modelling techniques for disease mapping using WinBUGS software. The thesis identified an overall earthquake-exposure effect on mood and anxiety symptom treatments among Christchurch residents in the context of the earthquakes as they experienced stronger increases in the risk of being treated especially shortly after the catastrophic 2011 Christchurch earthquake compared to the rest of New Zealand. High-risk groups included females, elderly, children and those with a pre-existing mental illness with elderly and children especially at-risk in the context of the earthquakes. Looking at the spatio-temporal distribution of mood and anxiety symptom treatments in the Christchurch urban area, a high rates cluster ranging from the severely affected central city to the southeast was found post-disaster. Analysing residential exposure to various earthquake impacts found that living in closer proximity to more affected areas was identified as a risk factor for mood and anxiety symptom treatments, which largely confirms a dose-response relationship between level of affectedness and mood and anxiety symptom treatments. However, little changes in the spatial distribution of mood and anxiety symptom treatments occurred in the Christchurch urban area over time indicating that these results may have been biased by pre-existing spatial disparities. Additionally, the post-disaster mobility activity from severely affected eastern to the generally less affected western and northern parts of the city seemed to have played an important role as the strongest increases in treatment rates occurred in less affected northern areas of the city, whereas the severely affected eastern areas tended to show the lowest increases. An investigation into the different effects of mobility confirmed that within-city movers and temporary relocatees were generally more likely to receive care or treatment for mood or anxiety symptoms, but moving within the city was identified as a protective factor over time. In contrast, moving out of the city from minor, moderately or severely damaged plain areas of the city, which are generally less affluent than Port Hills areas, was identified as a risk factor in the second year post-disaster. Moreover, residents from less damaged plain areas of the city showed a decrease in the likelihood of receiving care or treatment for mood or anxiety symptoms compared to those from undamaged plain areas over time, which also contradicts a possible dose-response relationship. Finally, the effects of the social and physical environment, as well as community resilience on mood and anxiety symptom treatments among long-term stayers from Christchurch communities indicate an exacerbation of pre-existing mood and anxiety symptom treatment disparities in the city, whereas exposure to ‘felt’ earthquake intensities did not show a statistically significant effect. The findings of this thesis highlight the complex relationship between different levels of exposure to a severe natural disaster and adverse mental health outcomes in a severely affected region. It is one of the few studies that have access to area-wide health and impact information, are able to do a pre-disaster / post-disaster comparison and track their sample population to apply spatial and spatio-temporal analysis techniques for exposure assessment. Thus, this thesis enhances knowledge about the spatio-temporal distribution of adverse mental health outcomes in the context of a severe natural disaster and informs public health care planners, not only about high-risk groups, but also where and when to target health interventions. The results indicate that such programs should broadly target residents living in more affected areas as they are likely to face daily hardship by living in a disrupted environment and may have already been the most vulnerable ones before the disaster. Special attention should be focussed on women, elderly, children and people with pre-existing mental illnesses as they are most likely to receive care or treatment for stress-related mental health symptoms. Moreover, permanent relocatees from affected areas and temporarily relocatees shortly after the disaster may need special attention as they face additional stressors due to the relocation that may lead to the development of adverse mental health outcomes needing treatment.
The 2015 New Zealand strong-motion database provides a wealth of new strong motion data for engineering applications. An important component of this database is the compilation of new site metadata, describing the soil conditions and site response at GeoNet strong motion stations. We have assessed and compiled four key site parameters for the ~460 GeoNet stations that recorded significant historical ground motions. Parameters include: site classification (NZS1170.5), Vs30, fundamental site period (Tsite) and depth to bedrock (Z1.0, i.e. depth to material with Vs > 1000 m/s). In addition, we have assigned a quality estimate (Quality 1 – 3) to these parameters to provide a qualitative estimate of the uncertainty. New highquality Tsite estimates have largely been obtained from newly available HVSR amplification curves and spectral ratios from inversion of regional strong motion data that has been reconciled with available geological information. Good quality Vs30 estimates, typically in urban centres, have also been incorporated following recent studies. Where site-specific measurements of Vs30 are not available, Vs30 is estimated based on surface geology following national Vs30 maps. New Z1.0 values have been provided from 3D subsurface models for Canterbury and Wellington. This database will be used in efforts to guide development and testing of new and existing ground motion prediction models in New Zealand. In particular, it will allow reexamination of the most important site parameters that control and predict site response in a New Zealand setting. Furthermore, it can be used to provide information about suitable rock reference sites for seismological research, and as a guide to site-specific references in the literature. We discuss compilation of the database, preliminary insights so far, and future directions.
After a disaster, cities experience profound social and environmental upheaval. Current research on disasters describes this social disruption along with collective community action to provide support. Pre-existing social capital is recognised as fundamental to this observed support. This research examines the relationship between sense of place for neighbourhood, social connectedness and resilience. Canterbury residents experienced considerable and continued disruption following a large and protracted sequence of earthquakes starting in September 2010. A major aftershock on 22 February 2011 caused significant loss of life, destruction of buildings and infrastructure. Following this earthquake some suburbs of Christchurch showed strong collective action. This research examines the features of the built environment that helped to form this cooperative support. Data were collected through semi-structured interviews with 20 key informants followed by 38 participants from four case study suburbs. The objectives were to describe the community response of suburbs, to identify the key features of the built environment and the role of social infrastructure in fostering social connectedness. The last objective was to contribute to future planning for community resilience. The findings from this research indicated that social capital and community competence are significant resources to be called upon after a disaster. Features of the local environment facilitated the formation of neighbourhood connections that enabled participants to cope, manage and to collectively solve problems. These features also strengthened a sense of belonging and attachment to the home territory. Propinquity was important; the bumping and gathering places such as schools, small local shops and parks provided the common ground for meaningful pre-existing local interaction. Well-defined geography, intimate street typology, access to quality natural space and social infrastructure helped to build the local social connections and develop a sense of place. Resourceful individuals and groups were also a factor, and many are drawn to live near the inner city or more natural places. The features are the same well understood attributes that contribute to health and wellbeing. The policy and planning framework needs to consider broader social outcomes, including resilience in new and existing urban developments. The socio-political structures that provide access to secure and stable housing and local education should also be recognised and incorporated into local planning for resilience and the everyday.
Coastal and river environments are exposed to a number of natural hazards that have the potential to negatively affect both human and natural environments. The purpose of this research is to explain that significant vulnerabilities to seismic hazards exist within coastal and river environments and that coasts and rivers, past and present, have played as significant a role as seismic, engineering or socio-economic factors in determining the impacts and recovery patterns of a city following a seismic hazard event. An interdisciplinary approach was used to investigate the vulnerability of coastal and river areas in the city of Christchurch, New Zealand, following the Canterbury Earthquake Sequence, which began on the 4th of September 2010. This information was used to identify the characteristics of coasts and rivers that make them more susceptible to earthquake induced hazards including liquefaction, lateral spreading, flooding, landslides and rock falls. The findings of this research are applicable to similar coastal and river environments elsewhere in the world where seismic hazards are also of significant concern. An interdisciplinary approach was used to document and analyse the coastal and river related effects of the Canterbury earthquake sequence on Christchurch city in order to derive transferable lessons that can be used to design less vulnerable urban communities and help to predict seismic vulnerabilities in other New Zealand and international urban coastal and river environments for the future. Methods used to document past and present features and earthquake impacts on coasts and rivers in Christchurch included using maps derived from Geographical Information Systems (GIS), photographs, analysis of interviews from coastal, river and engineering experts, and analysis of secondary data on seismicity, liquefaction potential, geology, and planning statutes. The Canterbury earthquake sequence had a significant effect on Christchurch, particularly around rivers and the coast. This was due to the susceptibility of rivers to lateral spreading and the susceptibility of the eastern Christchurch and estuarine environments to liquefaction. The collapse of river banks and the extensive cracking, tilting and subsidence that accompanied liquefaction, lateral spreading and rock falls caused damage to homes, roads, bridges and lifelines. This consequently blocked transportation routes, interrupted electricity and water lines, and damaged structures built in their path. This study found that there are a number of physical features of coastal and river environments from the past and the present that have induced vulnerabilities to earthquake hazards. The types of sediments found beneath eastern Christchurch are unconsolidated fine sands, silts, peats and gravels. Together with the high water tables located beneath the city, these deposits made the area particularly susceptible to liquefaction and liquefaction-induced lateral spreading, when an earthquake of sufficient size shook the ground. It was both past and present coastal and river processes that deposited the types of sediments that are easily liquefied during an earthquake. Eastern Christchurch was once a coastal and marine environment 6000 years ago when the shoreline reached about 6 km inland of its present day location, which deposited fine sand and silts over this area. The region was also exposed to large braided rivers and smaller spring fed rivers, both of which have laid down further fine sediments over the following thousands of years. A significant finding of this study is the recognition that the Canterbury earthquake sequence has exacerbated existing coastal and river hazards and that assessments and monitoring of these changes will be an important component of Christchurch’s future resilience to natural hazards. In addition, patterns of recovery following the Canterbury earthquakes are highlighted to show that coasts and rivers are again vulnerable to earthquakes through their ability to recovery. This city’s capacity to incorporate resilience into the recovery efforts is also highlighted in this study. Coastal and river areas have underlying physical characteristics that make them increasingly vulnerable to the effects of earthquake hazards, which have not typically been perceived as a ‘coastal’ or ‘river’ hazard. These findings enhance scientific and management understanding of the effects that earthquakes can have on coastal and river environments, an area of research that has had modest consideration to date. This understanding is important from a coastal and river hazard management perspective as concerns for increased human development around coastlines and river margins, with a high seismic risk, continue to grow.
This dissertation explores the advocacy for the Christchurch Town Hall that occurred in 2012-2015 after the Canterbury Earthquakes. It frames this advocacy as an instance of collective-action community participation in a heritage decision, and explores the types of heritage values it expressed, particularly social values. The analysis contextualises the advocacy in post-quake Christchurch, and considers its relationship with other developments in local politics, heritage advocacy, and urban activism. In doing so, this dissertation considers how collective action operates as a form of public participation, and the practical implications for understanding and recognising social value. This research draws on studies of practices that underpin social value recognition in formal heritage management. Social value is held by communities outside institutions. Engaging with communities enables institutions to explore the values of specific places, and to realise the potential of activating local connections with heritage places. Such projects can be seen as participatory practices. However, these processes require skills and resources, and may not be appropriate for all places, communities and institutions. However, literature has understudied collective action as a form of community participation in heritage management. All participation processes have nuances of communities, processes, and context, and this dissertation analyses these in one case. The research specifically asked what heritage values (especially social values) were expressed through collective action, what the relationship was with the participation processes, communities, and wider situation that produced them, and the impact on institutional rhetoric and decisions. The research analysed values expressed in representations made to council in support of the Town Hall. It also used documentary sources and interviews with key informants to analyse the advocacy and decision-making processes and their relationships with the wider context and other grassroots activities. The analysis concluded that the values expressed intertwined social and professional values. They were related to the communities and circumstance that produced them, as an advocacy campaign for a civic heritage building from a Western architectural tradition. The advocacy value arguments were one of several factors that impacted the decision. They have had a lasting impact on rhetoric around the Town Hall, as was a heritage-making practice in its own right. This dissertation makes a number of contributions to the discussion of social value and community in heritage. It suggests connections between advocacy and participation perspectives in heritage. It recommends consideration of nuances of communities, context, and place meanings when using heritage advocacy campaigns as evidence of social value. It adds to the literature on heritage advocacy, and offers a focused analysis of one of many heritage debates that occurred in post-quake Christchurch. Ultimately, it encourages practice to actively integrate social and community values and to develop self-reflexive engagement and valuation processes. Despite inherent challenges, participatory processes offer opportunities to diversify understandings of value, co-produce heritage meanings with communities, and empower citizens in democratic processes around the places they live with and love.
During 2010 and 2011, major earthquakes caused widespread damage and the deaths of 185 people in the city of Christchurch. Damaged school buildings resulted in state intervention which required amendment of the Education Act of 1989, and the development of ‘site sharing agreements’ in undamaged schools to cater for the needs of students whose schools had closed. An effective plan was also developed for student assessment through establishing an earthquake impaired derived grade process. Previous research into traditional explanations of educational inequalities in the United Kingdom, the United States of America, and New Zealand were reviewed through various processes within three educational inputs: the student, the school and the state. Research into the impacts of urban natural disasters on education and education inequalities found literature on post disaster education systems but nothing could be found that included performance data. The impacts of the Canterbury earthquakes on educational inequalities and achievement were analysed over 2009-2012. The baseline year was 2009, the year before the first earthquake, while 2012 is seen as the recovery year as no schools closed due to seismic events and there was no state intervention into the education of the region. National Certificate of Educational Achievement (NCEA) results levels 1-3 from thirty-four secondary schools in the greater Christchurch region were graphed and analysed. Regression analysis indicates; in 2009, educational inequalities existed with a strong positive relationship between a school’s decile rating and NCEA achievement. When schools were grouped into decile rankings (1-10) and their 2010 NCEA levels 1-3 results were compared with the previous year, the percentage of change indicates an overall lower NCEA achievement in 2010 across all deciles, but particularly in lower decile schools. By contrast, when 2011 NCEA results were compared with those of 2009, as a percentage of change, lower decile schools fared better. Non site sharing schools also achieved higher results than site sharing schools. State interventions, had however contributed towards student’s achieving national examinations and entry to university in 2011. When NCEA results for 2012 were compared to 2009 educational inequalities still exist, however in 2012 the positive relationship between decile rating and achievement is marginally weaker than in 2009. Human ethics approval was required to survey one Christchurch secondary school community of students (aged between 12 and 18), teachers and staff, parents and caregivers during October 2011. Participation was voluntary and without incentives, 154 completed questionnaires were received. The Canterbury earthquakes and aftershocks changed the lives of the research participants. This school community was displaced to another school due to the Christchurch earthquake on 22 February 2011. Research results are grouped under four geographical perspectives; spatial impacts, socio-economic impacts, displacement, and health and wellbeing. Further research possibilities include researching the lag effects from the Canterbury earthquakes on school age children.
The research presented in this thesis investigated the environmental impacts of structural design decisions across the life of buildings located in seismic regions. In particular, the impacts of expected earthquake damage were incorporated into a traditional life cycle assessment (LCA) using a probabilistic method, and links between sustainable and resilient design were established for a range of case-study buildings designed for different seismic performance objectives. These links were quantified using a metric herein referred to as the seismic carbon risk, which represents the expected environmental impacts and resource use indicators associated with earthquake damage during buildings’ life. The research was broken into three distinct parts: (1) a city-level evaluation of the environmental impacts of demolitions following the 2010/2011 Canterbury earthquake sequence in New Zealand, (2) the development of a probabilistic framework to incorporate earthquake damage into LCA, and (3) using case-study buildings to establish links between sustainable and resilient design. The first phase of the research focused on the environmental impacts of demolitions in Christchurch, New Zealand following the 2010/2011 Canterbury Earthquake Sequence. This large case study was used to investigate the environmental impact of the demolition of concrete buildings considering the embodied carbon and waste stream distribution. The embodied carbon was considered here as kilograms of CO2 equivalent that occurs on production, construction, and waste management stage. The results clearly demonstrated the significant environmental impacts that can result from moderate and large earthquakes in urban areas, and the importance of including environmental considerations when making post-earthquake demolition decisions. The next phase of the work introduced a framework for incorporating the impacts of expected earthquake damage based on a probabilistic approach into traditional LCA to allow for a comparison of seismic design decisions using a carbon lens. Here, in addition to initial construction impacts, the seismic carbon risk was quantified, including the impacts of seismic repair activities and total loss scenarios assuming reconstruction in case of non-reparability. A process-based LCA was performed to obtain the environmental consequence functions associated with structural and non-structural repair activities for multiple environmental indicators. In the final phase of the work, multiple case-study buildings were used to investigate the seismic consequences of different structural design decisions for buildings in seismic regions. Here, two case-study buildings were designed to multiple performance objectives, and the upfront carbon costs, and well as the seismic carbon risk across the building life were compared. The buildings were evaluated using the framework established in phase 2, and the results demonstrated that the seismic carbon risk can significantly be reduced with only minimal changes to the upfront carbon for buildings designed for a higher base shear or with seismic protective systems. This provided valuable insight into the links between resilient and sustainable design decisions. Finally, the results and observations from the work across the three phases of research described above were used to inform a discussion on important assumptions and topics that need to be considered when quantifying the environmental impacts of earthquake damage on buildings. These include: selection of a non-repairable threshold (e.g. a value beyond which a building would be demolished rather than repaired), the time value of carbon (e.g. when in the building life the carbon is released), the changing carbon intensity of structural materials over time, and the consideration of deterministic vs. probabilistic results. Each of these topics was explored in some detail to provide a clear pathway for future work in this area
The Avon-Heathcote Estuary is of significant value to Christchurch due to its high productivity, biotic diversity, proximity to the city, and its cultural, recreational and aesthetic qualities. Nonetheless, it has been subjected to decades of degradation from sewage wastewater discharges and encroaching urban development. The result was a eutrophied estuary, high in nitrogen, affected by large blooms of nuisance macroalgae and covered by degraded sediments. In March 2010, treated wastewater was diverted from the estuary to a site 3 km offshore. This quickly reduced water nitrogen by 90% within the estuary and, within months, there was reduced production of macroalgae. However, a series of earthquakes beginning in September 2010 brought massive changes: tilting of the estuary, changes in channels and water flow, and a huge influx of liquefied sediments that covered up to 65% of the estuary floor. Water nitrogen increased due to damage to sewage infrastructure and the diversion pipeline being turned off. Together, these drastically altered the estuarine ecosystem. My study involves three laboratory and five in situ experiments that investigate the base of the food chain and responses of benthic microalgae to earthquake-driven sediment and nutrient changes. It was predicted that the new sediments would be coarser and less contaminated with organic matter and nutrients than the old sediments, would have decreased microalgal biomass, and would prevent invertebrate grazing and bioturbation activities. It was believed that microalgal biomass would become similar across new and old sediments types as the unstable new sediments were resuspended and distributed over the old sediments. Contact cores of the sediment were taken at three sites, across a eutrophication gradient, monthly from September 2011 to March 2012. Extracted chlorophyll a pigments showed that microalgal biomass was generally lower on new liquefied sediments compared to old sediments, although there was considerable site to site variation, with the highly eutrophic sites being the most affected by the emergence of the new sediments. Grazer experiments showed that invertebrates had both positive and negative site-specific effects on microalgal biomass depending on their identity. At one site, new sediments facilitated grazing by Amphibola crenata, whereas at another site, new sediments did not alter the direct and indirect effects of invertebrates (Nicon aestuariensis, Macropthalmus hirtipes, and A. crenata) on microalgae. From nutrient addition experiments it was clear that benthic microalgae were able to use nutrients from within both old and new sediments equally. This implied that microalgae were reducing legacy nutrients in both sediments, and that they are an important buffer against eutrophication. Therefore, in tandem with the wastewater diversion, they could underpin much of the recovery of the estuary. Overall, the new sediments were less favourable for benthic microalgal growth and recolonisation, but were less contaminated than old sediments at highly eutrophic sites. Because the new sediments were less contaminated than the old sediments, they could help return the estuary to a noneutrophic state. However, if the new sediments, which are less favourable for microalgal growth, disperse over the old sediments at highly eutrophic sites, they could become contaminated and interfere with estuarine recovery. Therefore, recovery of microalgal communities and the estuary was expected to be generally long, but variable and site-specific, with the least eutrophic sites recovering quickly, and the most eutrophic sites taking years to return to a pre-earthquake and non-eutrophied state. changes in channels and water flow, and a huge influx of liquefied sediments that covered up to 65% of the estuary floor. Water nitrogen increased due to damage to sewage infrastructure and the diversion pipeline being turned off. Together, these drastically altered the estuarine ecosystem. My study involves three laboratory and five in situ experiments that investigate the base of the food chain and responses of benthic microalgae to earthquake-driven sedimen tand nutrient changes. It was predicted that the new sediments would be coarser and less contaminated with organic matter and nutrients than the old sediments, would have decreased microalgal biomass, and would prevent invertebrate grazing and bioturbation activities. It was believed that microalgal biomass would become similar across new and old sediments types as the unstable new sediments were resuspended and distributed over the old sediments. Contact cores of the sediment were taken at three sites, across a eutrophication gradient, monthly from September 2011 to March 2012. Extracted chlorophyll a pigments showed that microalgal biomass was generally lower on new liquefied sediments compared to old sediments, although there was considerable site to site variation, with the highly eutrophic sites being the most affected by the emergence of the new sediments. Grazer experiments showed that invertebrates had both positive and negative site-specific effects on microalgal biomass depending on their identity. At one site, new sediments facilitated grazing by Amphibola crenata, whereas at another site, new sediments did not alter the direct and indirect effects of invertebrates (Nicon aestuariensis, Macropthalmus hirtipes, and A. crenata) on microalgae. From nutrient addition experiments it was clear that benthic microalgae were able to use nutrients from within both old and new sediments equally. This implied that microalgae were reducing legacy nutrients in both sediments, and that they are
Mitigating the cascade of environmental damage caused by the movement of excess reactive nitrogen (N) from land to sea is currently limited by difficulties in precisely and accurately measuring N fluxes due to variable rates of attenuation (denitrification) during transport. This thesis develops the use of the natural abundance isotopic composition of nitrate (δ15N and δ18O of NO₃-) to integrate the spatialtemporal variability inherent to denitrification, creating an empirical framework for evaluating attenuation during land to water NO₃- transfers. This technique is based on the knowledge that denitrifiers kinetically discriminate against 'heavy' forms of both N and oxygen (O), creating a parallel enrichment in isotopes of both species as the reaction progresses. This discrimination can be quantitatively related to NO₃- attenuation by isotopic enrichment factors (εdenit). However, while these principles are understood, use of NO₃- isotopes to quantify denitrification fluxes in non-marine environments has been limited by, 1) poor understanding of εdenit variability, and, 2) difficulty in distinguishing the extent of mixing of isotopically distinct sources from the imprint of denitrification. Through a combination of critical literature analysis, mathematical modelling, mesocosm to field scale experiments, and empirical studies on two river systems over distance and time, these short comings are parametrised and a template for future NO₃- isotope based attenuation measurements outlined. Published εdenit values (n = 169) are collated in the literature analysis presented in Chapter 2. By evaluating these values in the context of known controllers on the denitrification process, it is found that the magnitude of εdenit, for both δ15N and δ18O, is controlled by, 1) biology, 2) mode of transport through the denitrifying zone (diffusion v. advection), and, 3) nitrification (spatial-temporal distance between nitrification and denitrification). Based on the outcomes of this synthesis, the impact of the three factors identified as controlling εdenit are quantified in the context of freshwater systems by combining simple mathematical modelling and lab incubation studies (comparison of natural variation in biological versus physical expression). Biologically-defined εdenit, measured in sediments collected from four sites along a temperate stream and from three tropical submerged paddy fields, varied from -3‰ to -28‰ depending on the site’s antecedent carbon content. Following diffusive transport to aerobic surface water, εdenit was found to become more homogeneous, but also lower, with the strength of the effect controlled primarily by diffusive distance and the rate of denitrification in the sediments. I conclude that, given the variability in fractionation dynamics at all levels, applying a range of εdenit from -2‰ to -10‰ provides more accurate measurements of attenuation than attempting to establish a site-specific value. Applying this understanding of denitrification's fractionation dynamics, four field studies were conducted to measure denitrification/ NO₃- attenuation across diverse terrestrial → freshwater systems. The development of NO₃- isotopic signatures (i.e., the impact of nitrification, biological N fixation, and ammonia volatilisation on the isotopic 'imprint' of denitrification) were evaluated within two key agricultural regions: New Zealand grazed pastures (Chapter 4) and Philippine lowland submerged rice production (Chapter 5). By measuring the isotopic composition of soil ammonium, NO₃- and volatilised ammonia following the bovine urine deposition, it was determined that the isotopic composition of NO₃ - leached from grazed pastures is defined by the balance between nitrification and denitrification, not ammonia volatilisation. Consequently, NO₃- created within pasture systems was predicted to range from +10‰ (δ15N)and -0.9‰ (δ18O) for non-fertilised fields (N limited) to -3‰ (δ15N) and +2‰ (δ18O) for grazed fertilised fields (N saturated). Denitrification was also the dominant determinant of NO₃- signatures in the Philippine rice paddy. Using a site-specific εdenit for the paddy, N inputs versus attenuation were able to be calculated, revealing that >50% of available N in the top 10 cm of soil was denitrified during land preparation, and >80% of available N by two weeks post-transplanting. Intriguingly, this denitrification was driven by rapid NO₃- production via nitrification of newly mineralised N during land preparation activities. Building on the relevant range of εdenit established in Chapters 2 and 3, as well as the soil-zone confirmation that denitrification was the primary determinant of NO₃- isotopic composition, two long-term longitudinal river studies were conducted to assess attenuation during transport. In Chapter 6, impact and recovery dynamics in an urban stream were assessed over six months along a longitudinal impact gradient using measurements of NO₃- dual isotopes, biological populations, and stream chemistry. Within 10 days of the catastrophic Christchurch earthquake, dissolved oxygen in the lowest reaches was <1 mg l⁻¹, in-stream denitrification accelerated (attenuating 40-80% of sewage N), microbial biofilm communities changed, and several benthic invertebrate taxa disappeared. To test the strength of this method for tackling the diffuse, chronic N loading of streams in agricultural regions, two years of longitudinal measurements of NO₃- isotopes were collected. Attenuation was negatively correlated with NO₃- concentration, and was highly dependent on rainfall: 93% of calculated attenuation (20 kg NO₃--N ha⁻¹ y⁻¹) occurred within 48 h of rainfall. The results of these studies demonstrate the power of intense measurements of NO₃- stable isotope for distinguishing temporal and spatial trends in NO₃ - loss pathways, and potentially allow for improved catchment-scale management of agricultural intensification. Overall this work now provides a more cohesive understanding for expanding the use of NO₃- isotopes measurements to generate accurate understandings of the controls on N losses. This information is becoming increasingly important to predict ecosystem response to future changes, such the increasing agricultural intensity needed to meet global food demand, which is occurring synergistically with unpredictable global climate change.
