A Geospatial Assessment of Critical Infrastructure Impacts and Adaptations in Small Rural Towns Following the 14 November 2016 (Kaikōura) Earthquake, New Zealand
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Japanese Geotechnical Society Special Publication GIS and Geoinformation Zoning for Disaster Mitigation (GIZ2018) A geospatial assessment of critical infrastructure impacts and adaptations in small rural towns following the 14 November 2016 (Kaikōura) earthquake, New Zealand D. J. McKibbin i), D. M. Blake ii), T. M. Wilson iii), L. Wotherspoon iv), and M. W. Hughes v) i) MSc Student, Department of Geological Sciences, University of Canterbury, 20 Kirkwood Ave, Christchurch 8041, New Zealand. ii) Postdoctoral Fellow, Department of Geological Sciences, University of Canterbury, 20 Kirkwood Ave, Christchurch 8041, New Zealand. iii) Assoc. Professor, Department of Geological Sciences, University of Canterbury, 20 Kirkwood Ave, Christchurch 8041, New Zealand. iv) Senior Lecturer, Civil and Environmental Engineering Department, University of Auckland, Auckland 1010, New Zealand. v) Lecturer, Department of Civil and Natural Resources Engineering, University of Canterbury, 20 Kirkwood Ave, Christchurch 8041, New Zealand ABSTRACT Geographically remote, small rural towns typically rely on multiple critical infrastructure networks with limited redundancies to support key services. Additionally, facilities that people take for granted in larger population centres, such as supermarkets and schools, are more widely distributed in low population density regions. We adopt the 14 November 2016 (Kaikōura) earthquake in New Zealand as a case study to explore critical infrastructure challenges and impacts, service disruptions, and community adaptations in four small North Canterbury and Marlborough towns – Waiau, Culverden, Seddon and Ward. However, behavioural, infrastructure and legislative adaptations can be inherent or quick to evolve in small towns with frequent service disruptions. Despite these factors, small towns are often underrepresented in impact assessments and appear to have been a low priority for investigation in the past. For the purposes of this paper we focus on the small rural town of Waiau in North Canterbury. Existing records of impacts and adaptations were combined with seismic and co-seismic hazards and emergency management activities to produce a preliminary geospatial timeline of events following the Kaikōura earthquake. Overlaying critical infrastructure with known and simulated co-seismic hazards enables us to conceptualise areas of high hazard exposure; an important component of risk. Along with the results of our discussions with community and industry members, this information can be fed into future research to inform resilience-building efforts. In this paper we present the latest findings and suggest future applications for Geospatial Information Systems in reducing disaster risk in small towns. Keywords: small towns, rural, infrastructure, hazards, disaster risk reduction, resilience, emergency management, Kaikōura earthquake 1 INTRODUCTION AND BACKGROUND (Hughes, et al., 2017). A large amount of long-term 1 ground deformation has also been observed, such as the The Mw 7.8 Kaikōura earthquake occurred at uplift of the shore along Kaikōura, with on-going 12.02am on 14 November 2016, with an epicentre 15 consequences. km deep, and 95 km north-east of Christchurch in the Within the context of natural disaster impacts, rural South Island of New Zealand (Fig. 1) (GeoNet, 2016). towns encounter a number of resilience challenges Strong shaking rocked buildings in both the North and distinct from large urban centres. This can manifest as South Islands causing liquefaction and multiple a result of low population density, which reduces tax landslides in the latter (Hughes, et al., 2017). Surface income – and therefore impedes investment in rupture also split roads and other infrastructure infrastructure resilience and maintenance (Howard, 1 The common name of ‘Kaikōura Earthquake’ is controversial so has drawn away attention from smaller towns (Hatton, et al., as impacts were felt widely across North Canterbury and 2017). Marlborough, and many locals feel that naming the earthquake https://doi.org/10.3208/jgssp.v06.GIZ04 19 2015). Additionally, the low population density of areas. This is not a legal classification; however it is rural regions widens the distribution of important sufficiently descriptive of the style of communities we facilities such as schools and supermarkets (Gerald, wish to investigate. 2016). In the context of lifeline utilities infrastructure, The value of Geospatial Information Systems (GIS) overcoming these challenges early on in response and lies in mapping out hazards and communities, and then recovery can help to reduce population displacement from this evaluating actual and potential exposure. and other societal effects. While much work has been Here, a geospatial assessment of critical done on large urban centres (Giovinazzi, et al., 2011; infrastructure impacts and related adaptations is O'Rourke, et al., 2012; Kongar, et al., 2017), small conducted using the 14 November 2016 (Kaikōura) towns and their communities have been comparatively earthquake in New Zealand as a case study. side-lined from research foci. New Zealand is Interdependencies between infrastructure types and considered the No.1 sheep meat and dairy exporter, entities are also considered in this assessment. While and therefore exports rely significantly on the several towns are being investigated in this project, for agricultural sector (MPI, 2018). For this reason, the the purpose of this paper we focus on Waiau in the resilience of the small towns which service agricultural Hurunui District of the North Canterbury region of industries should not be overlooked. South Island, New Zealand. Findings of our interviews thus far have outlined the damage to infrastructure in this township in particular. 2 METHODS a We established a general study area in the North Canterbury/Marlborough region based on felt reports published by GeoNet (GeoNet, 2016). Then, thirteen rural South Island towns that fell within this study area were considered for further investigation. Towns were evaluated in a points-based suitability b matrix, with scoring achieved by meeting the c aforementioned population and rurality requirements, d e variety in dominant industry types and known hazard impacts. Adaptations already identified in literature f g were also desirable. Our final selection gave four towns – Culverden and Waiau in North Canterbury, and Seddon and Ward in Marlborough: Culverden (pop. 426) is in the Hurunui District of the North Canterbury region. Considered the ‘hub’ of farming in the district, it is the commercial centre for many agricultural activities (Hurunui District Council, n.d.). In spite of its close proximity to the case study earthquake epicentre, destruction was relatively low compared to many other towns in the Hurunui District. Prominent lifeline utility impacts included broken and blocked roads, and a power outage. Waiau (pop. 261) is located just north-east of Culverden within Hurunui District, North Canterbury. The township is involved in services supporting Fig. 1: Map of the South Island of New Zealand with relevant locations notated. a: Seddon, b: Ward, c: Kaikōura, d: traditional large-scale farming. Local infrastructure Waiau, e: epicentre of the 14th November 2016 event, f: was hit quite badly with extensive damage to housing, Culverden, g: Christchurch. public/social buildings, commercial buildings, roads, three waters, and electricity distribution. There is no universal definition of a small town, Seddon (pop. 507) is situated in the Marlborough rural or otherwise, so for the purposes of our District, Marlborough region. Major industries here investigation we have taken the upper population limit include farming, lime quarrying and the Lake of the StatsNZ definition of 999 people (StatsNZ, n.d.). Grassmere salt ponds. The council water supply was Population data for towns was retrieved from the 2013 damaged in Seddon, along with the SH1 connection to New Zealand Census. StatsNZ’s definition also Blenheim and minor routes to more remote farming requires the town to service surrounding rural industry, homesteads. which is distinct from providing labour for main urban Ward (pop. 903) is the second town we are 20 investigating in the Marlborough District, infrastructure entities rely on another, either to Marlborough. Pastoral farming and fisheries are the facilitate business-as-usual performance or restoration industries of greatest importance to the township. following disruptions. In each of these cases, the Ward infrastructure was severely damaged by the criticality of dependent infrastructure is shared earthquake – notably telecommunication towers, between them. A common form of interdependence, downed powerlines, sceptic tanks and water which also tends to result in the development of distribution. Shore platform uplift also rendered the pinchpoints for linear infrastructure, is the utility of local fishing boat launch unusable. bridges to carry service infrastructure across rivers and For the purpose of this paper Waiau is the primary unlevel ground (Palermo, et al., 2017). A second mode case study. This township was chosen due to the high of interdependence is that of road access allowing for intensity of impacts and adaptation information from the recovery of other infrastructure types such as water the interviews conducted to date. supply networks. 2.1 Disaster risk and resilience 2.5 Pinchpoints and interdependent infrastructure A frequent issue with communicating disaster We suggest a simple method of