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Research papers, Lincoln University

Study region: Christchurch, New Zealand. Study focus: Low-lying coastal cities worldwide are vulnerable to shallow groundwater salinization caused by saltwater intrusion and anthropogenic activities. Shallow groundwater salinization can have cascading negative impacts on municipal assets, but this is rarely considered compared to impacts of salinization on water supply. Here, shallow groundwater salinity was sampled at high spatial resolution (1.3 piezometer/km²), then mapped and spatially interpolated. This was possible due to a uniquely extensive set of shallow piezometers installed in response to the 2010–11 Canterbury Earthquake Sequence to assess liquefaction risk. The municipal assets located within the brackish groundwater areas were highlighted. New hydrological insights for the region: Brackish groundwater areas were centred on a spit of coastal sand dunes and inside the meander of a tidal river with poorly drained soils. The municipal assets located within these areas include: (i) wastewater and stormwater pipes constructed from steel-reinforced concrete, which, if damaged, are vulnerable to premature failure when exposed to chloride underwater, and (ii) 41 parks and reserves totalling 236 ha, within which salt-intolerant groundwater-dependent species are at risk. This research highlights the importance of determining areas of saline shallow groundwater in low-lying coastal urban settings and the co-located municipal assets to allow the prioritisation of sites for future monitoring and management.

Research papers, The University of Auckland Library

Past earthquakes have consistently highlighted the vulnerabilities of the built environment. Current building codes, which focus primarily on life safety, fail to address the need for buildings to remain functional after a seismic event. The emerging concept of post-earthquake functional recovery aims to integrate recovery-based objectives into building codes. However, literature reveals a predominant focus on engineering parameters, with limited attention given to the perspectives of building users; a critical gap in understanding a building’s comprehensive functionality and path to functional recovery. Whilst structural integrity is essential, functionality following a disaster is not determined by physical stability alone. Thus, this study addresses this gap by exploring the perceptions and expectations of office building users (both tenants and property owners) regarding building functionality and post-earthquake functional recovery in New Zealand’s major urban centres: Wellington, Auckland, and Christchurch. A qualitative research strategy was employed, utilising interpretative phenomenological and grounded theory methods to develop insights from the lived experiences of twenty-six (26) participants. The study applied a systems thinking approach using a socio-technical systems (STS) framework to develop micro (single construct) and macro (multiple constructs) models of building-system functionality. The findings demonstrate that a building’s functionality is nuanced, multifaceted, and context dependent. It encompasses physical, economic, social, organisational, technical, regulatory, and environmental elements, and is ultimately determined by users’ specific needs and priorities. A key divergence emerged: whilst property owners prioritise economic and environmental factors, tenants focus on the socio-organisational aspect, viewing the physical workspace as an embodiment of corporate identity, culture, and values. Regarding expectations for post-earthquake functional recovery, the post-pandemic era has drastically reshaped outlooks. Unlike previous earthquakes, where tenants scrambled for any available space, there is now increased demand for flexibility due to the hybrid work model. The immediate return to an office following a major earthquake is now expected to support critical business functions, with essential services including power or a standby generator, technology to access files, water, as well as operations of air conditioning and elevators. By advancing socio-technical systems theory and elucidating building users’ perspectives for a building’s functionality and post-disaster functional recovery, this research provides evidence-based, social science insights to inform more holistic and effective risk governance in property and disaster risk management

Research papers, University of Canterbury Library

The 2010-2011 Canterbury earthquake sequence, and the resulting extensive data sets on damaged buildings that have been collected, provide a unique opportunity to exercise and evaluate previously published seismic performance assessment procedures. This poster provides an overview of the authors’ methodology to perform evaluations with two such assessment procedures, namely the P-58 guidelines and the REDi Rating System. P-58, produced by the Federal Emergency Management Agency (FEMA) in the United States, aims to facilitate risk assessment and decision-making by quantifying earthquake ground shaking, structural demands, component damage and resulting consequences in a logical framework. The REDi framework, developed by the engineering firm ARUP, aids stakeholders in implementing resilience-based earthquake design. Preliminary results from the evaluations are presented. These have the potential to provide insights on the ability of the assessment procedures to predict impacts using “real-world” data. However, further work remains to critically analyse these results and to broaden the scope of buildings studied and of impacts predicted.

Research papers, University of Canterbury Library

Natural catastrophes are increasing worldwide. They are becoming more frequent but also more severe and impactful on our built environment leading to extensive damage and losses. Earthquake events account for the smallest part of natural events; nevertheless seismic damage led to the most fatalities and significant losses over the period 1981-2016 (Munich Re). Damage prediction is helpful for emergency management and the development of earthquake risk mitigation projects. Recent design efforts focused on the application of performance-based design engineering where damage estimation methodologies use fragility and vulnerability functions. However, the approach does not explicitly specify the essential criteria leading to economic losses. There is thus a need for an improved methodology that finds the critical building elements related to significant losses. The here presented methodology uses data science techniques to identify key building features that contribute to the bulk of losses. It uses empirical data collected on site during earthquake reconnaissance mission to train a machine learning model that can further be used for the estimation of building damage post-earthquake. The first model is developed for Christchurch. Empirical building damage data from the 2010-2011 earthquake events is analysed to find the building features that contributed the most to damage. Once processed, the data is used to train a machine-learning model that can be applied to estimate losses in future earthquake events.