NATURAL HAZARDS 2018 Front: Clockwise beginning Top, left: A sediment core collected near Lake Grassmere. Photo: GNS Science; Road damage caused by the Kaiko-ura earthquake. Photo: GNS Science; Storm on the south coast. Photo: NIWA; Mt Tongariro fumarole. Photo: GNS Science. Back: Mt Ruapehu crater lake. Photo: GNS Science.

Citation Pinal C, Coomer M (2019) Natural Hazards 2018. Lower Hutt, NZ: GNS Science. GNS Science Miscellaneous Series 127, 60 pages. DOI: 10.21420/KJNM-R522

ISBN: 978-1-98-856938-3 (Print) ISBN: 978-1-98-856939-0 (Online) ISSN: 1177-2441 (Print) ISSN: 1172-2886 (Online) FOREWORD 1

FOREWORD

Te-na koutou ka-toa. To the Platform Management Group comprised of Kelvin Berryman (Director; Welcome to the final issue of ‘Natural 2009-15); Terry Webb, Gill Jolly, Hannah Hazards’ compiled by the Natural Hazards Brackley (GNS); Murray Poulter, Sam Dean Research Platform (NHRP). In this issue, we (NIWA); Jarg Pettinga, Rajesh Dhakal (UC), look back on what we’ve achieved together Michael Davies, Pierre Quenneville (UA), and where we go from here. Peter Kemp (Massey); Ben Holland, Peter Over its 10-year life, the NHRP has worked Benfell and Wendy Turvey (WSP-Opus). across disciplines to increase ’s Your collective wisdom of the geophysical, resilience to natural hazards. We combined engineering, and social sciences, the the efforts of the geophysical, engineering pathways towards shaping natural hazards and social sciences to address our risks resilience and your willingness to share from natural hazards, while working more that knowledge and experience has been closely with end-users for delivery of the inspiring. It was a pleasure to work with you. research outputs. To the Strategic Advisory Group, led by Over that time, we saw an increased number David Middleton since 2009 – thank you for of natural hazard events. Two notable the time you have given to the NHRP. During - earthquakes, volcanic eruption, extreme the Christchurch and Kaikoura earthquakes, weather causing wind, flood, and storm your own agencies were stretched but you damage – all of these impacted on people always made yourselves available. Your advice and infrastructure. was hugely appreciated – Richard Smith, Sarah Stuart-Black, Roger Fairclough, The NHRP was the first programme of its kind Basil Chamberlain, Mike Adye, Bryce Davies, in New Zealand. It could be considered the Mike Stannard, Adrian Bennett, Kieran Devine ‘pilot’ for the National Science Challenges, and Hilary Blake. including the Resilience to Nature’s Challenges, which features in this issue. And lastly, to the International Technical Advisory Group, led by Russell Blong Our research has also been influential (Australia; 2012-15), followed by George overseas. blue lines now exist in the Pankiewicz (UK) – thank you for staying in west coast of the USA and parts of Indonesia. touch from a distance. Your contributions And how we communicate earthquake to New Zealand’s natural hazards community aftershock forecasts has been received with have helped shape our work and future great interest by colleagues in Japan and directions – Bill Ellsworth (USA), Bill Holmes the USA. (USA), Stephanie Chang (Canada), So in this issue, we’ll look back at the Michael Lindell (USA), Stephen Sparks (UK), highlights of the past 10 years and activities Willy Aspinall (UK), Jim Hall (UK) and from current research projects. If you’d like Tom O’Rourke (USA). to see it all at a glance, see page 54 – our The NHRP’s contract ends on 31 October Hazards to Impact table attempts to put 10 2019, while the second phase of the years of work on a page (although it’s not an Resilience to Nature’s Challenges gets exhaustive list). underway for the next five years. Best wishes The NHRP has not been alone on this journey. to the Resilience Challenge team as they lead We gratefully acknowledge – us forward from here. Our end-users for challenging us as Catherine Pinal researchers to look at a problem through Natural Hazards Research Platform multiple lenses. To the NHRP theme leaders, project Building damage leaders and colleagues – thank you for caused by the 22 Feb 2011 Christchurch your dedication to teaching, research and earthquake. Photo: determination to inform others about GNS Science. natural hazards. 2 NATURAL HAZARDS | 2018

NATURAL HAZARDS 2018

01 Foreword 04 Geological Hazards Seismology and tsunami science – 06 14 20 A decade of significant progress THE KAIKŌURA EARTHQUAKE AND PAST NEW TOOLS FOR ASSESSING CLIMATE Lessons from New Zealand landslides FAULT RUPTURE CHANGE IMPACTS ON COASTAL HAZARDS 08 and rockfall By Rob Langridge and Kate Clark By Giovanni Coco and Karin Bryan Advances in New Zealand 10 volcanology The 2016 earthquake was one of the most Researchers have developed a free online Collapse or not? Exploring flank globally complex earthquakes to have tool to help New Zealanders understand the 12 collapse hazards of Mt Ruapehu occurred in modern times. Two research present and future changes in coastal hazards. teams tell us about their field work. The Kaiko-ura earthquake and past 14 fault rupture 16 Weather Flood Coastal A decade of advances in weather, 18 floods and coastal hazard research New tools for assessing climate 20 change impacts on coastal hazards Tools and knowledge to improve 22 New Zealand’s long-term resilience to wind storms 24 Societal Resilience Societal resilience research and its 26 impact over the past decade 28 Quicker, safer tsunami evacuations Adaptive and interactive futures: 30 A serious game for decision-making and coastal hazards Resilient engineering and 32 infrastructure Engineering and infrastructure 34 research Improving the design of new 35 buildings 38 Risk Progress in risk modelling in the era 40 of Natural Hazards Research Platform 41 RiskScape 2.0 – What is coming next? RiskScape team joins post-tsunami 42 survey in Indonesia 44 Resilience to Nature’s Challenges Towards resilience solutions for 46 rural regions The New Zealand Resilience Index 48 and measuring resilience Resilience to Nature’s Challenges 50 Looking ahead: 2019 to 2024 Natural hazards: A brief snapshot 52 of the main events of 2018 54 10 years of NHRP research 3

35 42 50 IMPROVING THE DESIGN OF RISKSCAPE TEAM JOINS POST-TSUNAMI RESILIENCE TO NATURE’S CHALLENGES NEW BUILDINGS SURVEY IN INDONESIA LOOKING AHEAD: 2019 TO 2024 By Rick Henry, Minghao Li, Chin-Long Lee, By Ryan Paulik, James Williams, By Richard Smith Greg MacRae and Charles Clifton Aditya Gusman and Sheng-Lin Lin The Resilience Challenge (RNC) is about to Engineers from the Universities of Following the Mw 7.5 Sulawesi earthquake embark on new research programmes for the and Canterbury report on the seismic and tsunami, a New Zealand field team next five years. Richard Smith, Director of the performance and design of structural systems accompanied Indonesian colleagues to RNC, tells us what’s in store. popular in new buildings. record damages. They share their findings in this report. 4 NATURAL HAZARDS | 2018

GEOLOGICAL HAZARDS 5

All photos GNS Science. 6 NATURAL HAZARDS | 2018 10 YEARS SEISMOLOGY AND TSUNAMI SCIENCE – A DECADE OF SIGNIFICANT PROGRESS

Along the way, our science has evolved very quickly in the seismology and tsunami space. By Stephen Bannister We have incorporated new large streams of data that were quite rare back in 2009, using vastly evolved techniques, and new The Natural Hazards Research Platform paradigms informed by knowledge from the was established at the beginning of a latest earthquakes, slow slip phenomena and period of substantial earthquake activity tsunami. Many of the changes in our science in New Zealand, leading to big changes were greatly assisted by the evolving network in public response mechanisms and new of GeoNet instrumentation and GeoNet data. science capabilities. The 2010 magnitude 7.1 Darfield earthquake, In the 30 years between 1979 and 2009 which began the extended Canterbury there were only seven earthquakes beneath earthquake sequence, involved rupture across New Zealand that were considered large a structurally complex fault network. As the (magnitude greater than 6) and shallow (less Canterbury sequence unfolded, including the than 40 km deep). Five of these occurred in 2011 magnitude 6.3 Christchurch earthquake, the 1990s. the importance of the pre-existing fault In comparison, since the inception of the network geometry, the role of earthquake Natural Hazards Research Platform (NHRP) in stress triggering, and the influence of crust 2009, New Zealand has experienced 12 such rheology were all notable. large earthquakes. These include the extensive However, what became very evident following 2010-2012 Canterbury earthquake sequence, the Canterbury sequence was the need for big the 2013 Cook Strait earthquakes, and the changes in how we communicated earthquake 2016 Kaiko-ura earthquake and aftershocks. aftershock forecasts and time-varying hazard to the public. In addition, there was a need to NHRP’S KEY ROLE OVER 10 YEARS see how our science was subsequently used in In these last 10 years, the NHRP has played a setting standards and public policy. critical role in helping coordinate the science response during natural hazard events, IMPACT OF 2016 KAIKŌURA EARTHQUAKE by organising the short-term response The 2016 magnitude 7.8 Kaiko-ura earthquake programmes which informed stakeholders was unprecedented in its complexity. Involving involved in recovery work, in addition at least 22 faults, scientists applied a range to coordinating the underpinning NHRP of methods – joint inversion of seismological, research already taking place. geodetic, fault geology, tsunami and GEOLOGICAL HAZARDS 7

InSAR data. We folded in LiDAR and coastal TSUNAMI uplift data to inform the details, along with CONTACT: offshore high-resolution multibeam data. The period since 2009 has also been the most active for tsunami in New Zealand. Stephen Bannister New approaches using dynamic rupture The 2009 Samoa tsunami had a big impact GNS Science simulations were applied to help understand on our South Pacific neighbours, with NHRP Theme Leader for Geological Hazards the multi-fault rupture. NHRP-funded projects New Zealand scientists identifying that the E-mail: [email protected] from the 2015 contestable round – Seismic tsunami was caused by not one but two hazard of Kekerengu Fault, led by Tim Little near-simultaneous earthquakes. (VUW), as well as Characterisation of active GNS Scientist Matt faulting earthquake sources in eastern In 2011, a magnitude 9.0 earthquake caused Gerstenberger devastation in Japan, and flooded houses in explains the aftershock Marlborough, led by Phil Barnes (NIWA) – forecasts to a were clearly prescient. the northern Coromandel – the first time this had occurred in New Zealand since 1960. crowd of 200 in the - Seddon community The impact from the Kaikoura earthquake on - meeting following the Wellington city infrastructure was larger than The 2016 Kaikoura earthquake generated a tsunami that inundated and badly damaged a 2013 Cook Strait- expected. It highlighted the increased need Lake Grassmere cottage on Banks Peninsula, and towns south to understand the role of the 3-D Wellington - earthquakes. basin structure on ground motions. There was of Kaikoura experienced a near-miss as the Photo: Derek Flynn, also the need to infer future ground motion tsunami ran-up 6-7 metres on embankments Marlborough Express. effects for future Wellington earthquakes, both between them and the sea. New Zealand crustal and on the Hikurangi megathrust, to researchers were instrumental in gathering inform revisions of Wellington building design the data on this tsunami, providing the only standards. The NHRP moved to address some clear picture of how far this earthquake of these needs in its Kaiko-ura short-term extended offshore. response projects. Significantly within the last 10 years, NHRP- Most recently, there has been an evolving funded research allowed us to develop the first understanding of how slow-slip events can model of tsunami hazard for all New Zealand modify the earthquake probabilities. This has coasts, and progress with the techniques that led to an increased effort in communicating have enabled much of the country to have the science behind slow-slip phenomena, tsunami evacuation zones mapped. the hazard from the Hikurangi subduction megathrust, as well as tsunami awareness, to the public and key agencies. 8 NATURAL HAZARDS | 2018 10 YEARS GEOLOGICAL HAZARDS 9

Dislodged boulders near the RSA clubrooms following the Feb 2011 Christchurch earthquake. Photo: Margaret Low, GNS Science.

Landslide dam along Hapuku River triggered by the Kaiko- ura Earthquake 2016. Photo: Dougal Townsend, GNS Science.

involved in the landslides helped us better sequence, including artificial intelligence By Sally Dellow and understand how these materials responded statistical techniques. to triggering events. Chris Massey The landslide datasets also include Data collected from repeat surveys of cliffs rainfall-induced landslides, which occur in the Sumner and Red Cliffs area using a frequently. A challenge has been how to The last 10 years have seen terrestrial laser scanner revealed that the acquire high-quality data to allow rainfall- amount of material shed by the cliffs was induced landslide forecasting models to be significant advancements in directly related to the strength of shaking, developed. The arrival of ex tropical cyclones the way landslides, landslide material type and slope geometry. Numerical to the vulnerable Kaiko-ura region resulted in modelling of slope behaviour and detailed remobilisation of landslide debris and failure hazards and landslide risk slope models built from the survey data are of cracked ground, causing ongoing hazards providing insights into the future behaviour of and risk to local residents. are treated in New Zealand. slopes, with strong potential to identify areas of future vulnerability. The ability to forecast rainfall-induced The Christchurch earthquake in February landslides is critical to understanding how 2011 was a turning point for researchers and In Christchurch, we undertook extensive changes in climate will impact our landscapes. policy makers. There were great challenges in risk analyses to prepare detailed maps of The consequent increase in hazards is likely gathering the data and expert opinion, and life-safety risks. These maps were used as the to result in much greater risks from landslides providing the advice necessary to the public basis for declaring 400 residential properties until we are managing those risks well. and decision-makers. unfit for habitation. The life-safety risks were deemed unacceptable (the properties CONTACT: But from this difficult period, landslide risk were ‘red-zoned’), and the life-safety risk Sally Dellow assessment in New Zealand came to be maps were subsequently used to update recognised as international best practice. Christchurch City Council’s District Plan. GNS Science Other countries learned from New Zealand’s E-mail: [email protected] Christchurch response, and it is that continual LESSONS FOR KAIKŌURA cycle of building upon the knowledge of past Affiliations events – here or overseas – that benefits us all. The lessons from Christchurch were put GNS Science: Chris Massey to good use following the 2016 Kaiko-ura Earthquake. A landslide dataset, containing WHAT WE LEARNT FROM CHRISTCHURCH nearly 30,000 individual landslides was The extended Canterbury earthquake compiled using high-resolution aerial sequence provided scientists with a wealth photography, LiDAR and oblique aerial of knowledge about rockfall, cliff collapse, photography. Research related to the and landslides and allowed us to develop Kaiko-ura landslide has been used to a comprehensive picture of landslide develop new earthquake-induced landslide hazards. Laboratory studies to characterise forecasting models using new methods not the properties of the rocks and soils available during the Canterbury earthquake 10 NATURAL HAZARDS | 2018 10 YEARS ADVANCES IN NEW ZEALAND VOLCANOLOGY Jonathan Procter discussing the lahar deposits in coastal By Jonathan Procter and the Volcano team Taranaki. Photo: Massey University. GEOLOGICAL HAZARDS 11

Mt Taranaki. Photo: Brad Scott, GNS Science.

New Zealand volcanology has had an important coming-of-age as a result of the Natural Hazards Research Platform.

The 1995 Mt Ruapehu eruption was the last including a ‘NZ Inc’ approach towards significant eruption to disrupt the everyday establishing a National Volcanic Hazard lives of New Zealanders. Volcanic ash closed Model for New Zealand [Bebbington, airports, damaged hydroelectric power NHRP Contest 2015]. facilities, closed major thoroughfares, and impacted agriculture, livestock and fisheries. We also respect the volcanoes we work on and the significant cultural connections Iwi The impacts from the 1995 eruption were and Ma-ori have with them. It is a privilege important to shaping the purpose of the to be able to explore those environments Natural Hazards Research Platform – bridging and in return share our knowledge with iwi. the geophysical, social, and economic We now lead internationally in developing dimensions of natural hazards research – methods to exchange knowledge between but also provided the impetus for the western science and indigenous knowledge greater collaboration needed during crises. systems for the betterment of all (Procter – NHRP Contest 2012 ‘Ma-tauranga Ma-ori for The 2012 Te Maari eruption, while relatively volcanic hazard’; and more recently with the small, produced pyroclastic density currents Resilience Challenge ‘Better Understanding (PDCs), a small debris avalanche, ballistic and Implementation of Ma-tauranga Ma-ori projectiles, ashfall and rock falls. Ballistic and Tikanga to Build Resilience’). impacts heavily damaged Ketetahi Hut on the Tongariro Alpine Crossing, which Meanwhile our research excellence continues fortunately was unoccupied at the time. to be noticed internationally. Our work on NHRP-funded research enabled us to take an eruption simulator for pyroclastic density a multi-disciplinary approach to explore currents has attracted international interest these impacts, generate new knowledge, and was featured in Nature Geoscience methodologies and produce world-leading (‘Experiments to save lives’ Nature science. The event was significant in that Geoscience, 12, 309 (2019). Our research in the greater collaboration led to the rapid Taranaki has also provided new directions development of hazard management for understanding and communicating products and strategies based on good volcanic hazard information by providing science that enabled greater preparation probabilities and computer simulations of and better response during the event. future events and scenarios that better inform emergency management plans. The research Our collective research on the 2012 eruption is recognised internationally as the future culminated in a series of publications in the direction of volcanic hazard analysis. Journal of Volcanology and Geothermal Research in addition to a report on volcanic CONTACT: hazard and risk for the UN Office of Disaster Risk Reduction, Global Assessment of Risk Jonathan Procter (‘GAR Reports), putting New Zealand’s Massey University practice of volcanology – in a hazard and E-mail: [email protected] risk context – on the world stage. Since Te Maari, we have continued to make advances, 12 NATURAL HAZARDS | 2018

COLLAPSE OR NOT? EXPLORING FLANK COLLAPSE HAZARDS OF MT RUAPEHU

Volcanic slopes may weaken and collapse. The hyperspectral imaging system is the first While less frequent than eruptions or lahars, of its kind in New Zealand, providing new By Gabor Kereszturi, these low probability, high-risk phenomena spectral datasets for mapping and modelling. Lauren Schaefer, Craig can trigger dangerous debris avalanches – On the same aerial surveys, hundreds of Miller and Stuart Mead a potentially hazardous mass flow of volcanic digital photos were taken, to depict the and non-volcanic particles. topography of Mt Ruapehu, providing a new high-resolution Digital Terrain Model through Mt Ruapehu has produced debris avalanches photogrammetry. In a first for the Southern over the past 200,000 years, with some Hemisphere, researchers travelling up to 50 km from their source. Hyperspectral imaging can measure reflected The sporadic occurrence of this high light at hundreds of wavelengths – beyond from Massey University, impact natural hazard poses challenges what is observable by the human . This University of Canterbury for accurately predicting the volume and extended spectral range allows quantification location of future events. of surface mineral composition changes that and GNS Science are indicate departures from strong, fresh lava STRONG ROCKS BECOME WEAK ROCKS rocks to hydrothermally altered weak rocks, applying state-of-the-art enabling us to create a detailed geotechnical technology to understand One way to address these hazards is by map of Mt Ruapehu. Combined with aero- quantifying the hydrothermal alteration history magnetic surveys, a detailed picture of the the risk of Mt Ruapehu of Mt Ruapehu. Hydrothermal alteration is a sub-surface distribution of hydrothermal process which turns already solidified rocks alteration begins to emerge. volcanic flank collapse. into easily deformable and weak rocks. We have collected a wide assortment of Hydrothermal alteration occurs as infiltrating hydrothermally altered rocks. This helps surface water and circulating groundwater are quantify the rock mechanical properties, such heated by the nearby stored magma bodies, as strength and porosity, as well as mineral- such as dykes and sills. This circulating proxies that indicate the degree of alteration. hot water becomes acidic over time which enhances its ability to dissolve volcanic rocks Rock strength data coupled with the surface and form new minerals, including clay, oxide and shallow sub-surface geophysical and sulfate minerals. information will be used to create a new geotechnical model that will be incorporated By changing the chemical composition into a stability assessment of Mt Ruapehu. of volcanic rocks, hydrothermal alteration This assessment will help us develop new undermines the physical strength of rocks. numerical simulations of the likely run-out These weakened volcanic rocks gradually distance of future debris flows. For the first become more susceptible to failure due to time ever, we will have a flank instability and gravitational, seismic and weather-related debris avalanche hazard map of Mt Ruapehu. triggers, thus producing debris avalanches. This project will greatly improve our NEW GEOPHYSICAL IMAGING TECHNIQUES understanding of Mt Ruapehu’s geological hazards and can be applied to other Our approach is to use advanced New Zealand volcanoes. hyperspectral imaging, photogrammetry and aeromagnetic surveys to map the surface of Mt Ruapehu and at depth below. GEOLOGICAL HAZARDS 13

Dr Gabor Kereszturi. Perspective view Photo courtesy of of the new point Massey University. cloud data with the location of the camera position (blue and green spheres) over Mt Ruapehu. Image: Gabor Kereszturi, Massey University.

CONTACT: Gabor Kereszturi Massey University E-mail: [email protected]

Affiliations University of Canterbury: Lauren Schaefer GNS Science: Craig Miller Massey University: Stuart Mead

YouTube video: For a spectacular view of the hyperspectral and topographic survey of the Mt Tongariro volcano in New Zealand see https://www.youtube.com/ watch?v=dLs97Ph7-aA 14 NATURAL HAZARDS | 2018

THE KAIKŌURA EARTHQUAKE AND PAST FAULT RUPTURE

The 2016 Mw 7.8 Kaiko-ura earthquake is one of the most By Rob Langridge globally complex earthquakes to have occurred in modern and Kate Clark times. New research is addressing whether the multi-fault rupture observed in the Kaiko-ura earthquake is typical for this part of the New Zealand plate boundary. The results will help us better understand how complex fault ruptures can be better incorporated into our hazard models.

Paleoseismologists taking measurements across the main strand of the Papatea fault. The fault heads down the hill to the right and into the Clarence River valley where major river diversion was caused by the vertical movement of the fault through the valley. Photo: Kate Clark, GNS Science.

~2600 years BP 2100 years BP 1500 years BP (~600 BC) (100 BC) (AD 500) GEOLOGICAL HAZARDS 15

- The Kaikoura earthquake ruptured at least UNDERSTANDING PAST EARTHQUAKES 20 faults in an approximately 200 km area in the north-eastern South Island. The A concurrent project is using the coastal earthquake caused significant landscape landscape record of uplifted marine terraces to understand past earthquakes along the change, such as coastal uplift, landslides, - river diversion across the North Canterbury Kaikoura – Marlborough coastline. and Marlborough regions, and a localised Many of the faults involved in the Kaiko-ura tsunami. Scientists Rob Langridge and earthquake either crossed the coastline or Kate Clark from GNS Science are leading were entirely offshore. Marine terraces offer teams of researchers from across New a method of understanding when the coastal Zealand to understand the complex event. and offshore faults last ruptured and the relative size of those earthquakes. INVESTIGATING THE PAPATEA FAULT This project is being led by Kate Clark With colleagues at the University of in collaboration with the University of Canterbury, University of Otago and Lincoln Auckland, NIWA and Victoria University of University, Rob Langridge is leading a project Wellington. Particular areas of focus are the to investigate the record of past surface Kaiko-ura Peninsula, Cape Campbell and the ruptures along the Hope-Seaward, Humps, coastline near the Papatea Fault. Preliminary Hundalee, and Papatea faults. results show there were at least one or two The Papatea Fault was one of the more earthquakes within the past 2000 years at all unusual fault ruptures of the Kaiko-ura sites, with the most frequent coastal uplift earthquake, with vertical offsets of up to occurring at Cape Campbell, consistent with 10 metres occurring on this fault up the the high slip rate of the offshore Needles Fault. Clarence River valley, along with multiple Our original view was that the 2016 large landslides. A major challenge with the Kaiko-ura earthquake was a very rare event Papatea Fault was finding locations where as it involved faults with extremely different the enormous 2016 fault offsets did not recurrence intervals. The research to date GNS scientist Rob inhibit fault trenching. supports this. Langridge (far right, in blue) at the Papatea In early 2019, three trenches were excavated Paleoseismology offers a pathway for Fault in the Clarence across the main strand and two minor splay understanding the frequency of multi-fault Valley. Photo: GNS faults off the Papatea Fault. Initial results earthquakes, and will enable insights into Science. from these trenches suggest there have future earthquake behaviour across the been two to four earthquake ruptures during complex plate boundary in the northern the Holocene period, including the 2016 South Island. earthquake. Another way to understand the Papatea Fault’s behaviour has been to investigate the record of fluvial and landscape CONTACT: change in the Clarence valley. Radiocarbon dating of deposits exposed by avulsion and Rob Langridge erosion indicates the previous episode of GNS Science major fluvial change in the valley occurred E-mail: [email protected] around 1000 or more years ago. Kate Clark GNS Science E-mail: [email protected]

A sediment core collected near Lake Grassmere, southeastern Marlborough. This core shows sudden influxes of coarse sediment that were probably deposited by past triggered by nearby fault ruptures. The information on past offshore fault ruptures can be integrated with paleoseismic records from onshore faults to understand past ~1300 years BP earthquakes. Photo: Kate Clark, GNS Science. (~AD 700) 16 NATURAL HAZARDS | 2018

WEATHER FLOOD COASTAL 17

Clockwise beginning Top, left: Wellington storm; Haumoana coastal erosion; Scientists at work during the 2014 Christchurch flood. Photos: NIWA; Bottom, left: 2017 Edgecumbe flood. Photo GNS Science. 18 NATURAL HAZARDS | 2018 10 YEARS A DECADE OF ADVANCES IN WEATHER, FLOODS, AND COASTAL HAZARD RESEARCH By Richard Turner WEATHER FLOOD COASTAL 19

Damaged irrigator in the aftermath of the 2013 Canterbury wind storm. Photo: Dave Allen, NIWA.

A ten-year milestone is a FLOOD FORECASTS FOR ALL OF NEW ZEALAND MODELLING ATMOSPHERIC FLOWS Another exciting project nearing completion Over the last 10 years, NIWA’s support good opportunity to look is the 2017 NHRP-funded ‘Enhanced of underpinning natural hazards research in the rear-view mirror, probabilistic flood forecasting…’ which will has been strategically aligned with NHRP/ generate high-resolution, probabilistic two- RNC investment. This has contributed to review achievements and day ahead flood (catchment) forecasts for all the advanced modelling capability for renew our enthusiasm of New Zealand. The forecasts are produced atmospheric flows, and this has benefited by using a complex Bayesian statistical some very practical applications such as for what lies ahead. Here method to create an unbiased spread (or ashfall dispersion from the 2012 Te Maari ensemble) of forecasted hourly rainfall rates at eruption, as well as the 2017 dispersal of are some highlights of grid points over a catchment that feed into a myrtle rust spores from Australia to New research conducted within river flow model. These unbiased ensembles Zealand and Raoul Island. It has also been are calculated on a fine spatial grid of 1.5 km a catalyst for upgrades to the emergency the Weather, Floods, and and forecasts are updated every six hours and plume dispersal modelling system which extend to 48 hours. operates at NIWA and is designed for Coast theme of the Natural modelling airborne disease outbreaks. The development of this method will enable Hazards Research Platform. the production of next generation forecasts The models and computational platforms as high-resolution weather ensemble upon which the weather, flood, and coasts The Natural Hazards Research Platform forecasts become available in New Zealand. hazard research depends would not be (NHRP) has been a great mechanism for This will allow for more realistic uncertainty possible without the support of High encouraging and funding collaboration (probabilistic) estimates (providing a range Performance Computing in New Zealand between weather researchers/modelers of outcomes) to be made in flood situations. that comes from the National e-Science and design/structural engineers working on Infrastructure. issues of importance to New Zealand, with COASTAL INUNDATION stakeholder engagement encouraged and CONTACT: supported. Climate change is a critical issue. The NHRP has supported a study led by the University of Richard Turner A good example of this collaboration was Auckland which has modelled and assessed NIWA the WSP-OPUS led project, ‘Improving coastal inundation due to tide, wave and NHRP Theme Leader in Weather, Flood and New Zealand’s resilience to wind storms’ conditions for current and future Coastal Hazards (Safei Pirooz et al, this issue). This project, storms that impact New Zealand. Impressive E-mail: [email protected] and earlier wind research within NHRP, has visualisation tools have been developed that contributed to a proposed major revision of demonstrate the changing risk over the next the New Zealand relevant portion of the wind century (Coco & Bryan, this issue). loading code (AS/NZS 1170.2). It has also led to better and verified methods in calculating effects of complex terrain on design winds. Brett Phibbs, NZ Herald. 20 NATURAL HAZARDS | 2018

A

By Giovanni Coco and Karin Bryan

In New Zealand, coastal erosion and coastal inundation are significant issues for decision-makers involved in land-use planning. There is a growing

B demand for robust evidence to understand both the present and future changes in coastal hazards.

(a) Map of model output showing generation region of coastal waves. Waves reaching the west coast of the New Zealand can be generated hundreds of kilometres away; (b) Snapshot of the webpage where storm surge data can be downloaded. WEATHER FLOOD COASTAL 21

(c) Mean sea level today; (d) Mean sea level in 2050; (e) Mean sea level in 2050 plus the combined effect of a large storm and king tides.

UNDERSTANDING NEW ZEALAND’S COASTAL The data can be downloaded at: https:// The tool allows the user to compare the coastalhub.science/storm-surge present conditions and the effect of sea level HAZARDS rise (Fig. c; Fig. d shows the predicted sea Coastal erosion and coastal inundation A hindcast of wave data is also available level in 2050). Using the tool, the user can are generated by a combination of three (https://coastalhub.science/data) and in the add the combined effect of sea level rise with key factors: near future, projections until the year 2100 a major storm and king tides (Fig. e). will be made available over the same portal. • extreme weather-related events This type of visualisation is particularly This work provides unprecedented access to relevant because it shows how the combined • how our climate has changed over time vital information needed to combat the future effect of all the possible components critically stresses caused by climate change. determines the severity of coastal flooding. • the systematic increases in sea level, Dr Tom Shand, Technical Director at waves and storm surge as a result of CONTACT: climate change. Tonkin + Taylor has found the data useful: “Thank you for making the wave and storm Giovanni Coco A collaborative project by the University of surge data available. As coastal practitioners, University of Auckland Auckland, University of Waikato and NIWA is our ability to help communities is dependent E-mail: [email protected] generating a nationwide set of projections of on having accurate data. These wave and nearshore wave and storm surge conditions. water level hindcasts will be extremely useful Karin Bryan The projections look at the next 80 years in understanding historic events allowing us University of Waikato using state-of-the-art modelling approaches. to more accurately predict future hazard and E-mail: [email protected] The most recent IPCC* emission scenarios to design more resilient structures.” and associated climate properties are used Visit us at www.coastalhub.science to drive these predictions of future wave and surge processes. VISUALISING COASTAL FLOODING Effective communication of the impacts of Our projections of wave climate and storm climate change is critical to facilitate uptake surge are obtained using an innovative of the findings. In collaboration with the “multi-model” approach, which combines Centre of e-Research from the University dynamical modelling and statistical of Auckland, we have developed a high- downscaling. It incorporates weather-type resolution coastal flooding visualisation for classification and clustering techniques (Fig. Auckland city, which is also available in Virtual a). The projections are calculated at a scale Reality mode. Sea level rise, king tides and of 10 kilometres for the whole New Zealand storm surge are the parameters available at: coastline. And for the first time, these data https://coastalhub.science/coastal-hazards are now publicly available through a free- access web-based platform (Fig. b). *IPCC: Intergovernmental Panel on Climate Change 22 NATURAL HAZARDS | 2018

TOOLS AND KNOWLEDGE TO IMPROVE NEW ZEALAND’S LONG-TERM RESILIENCE TO WIND STORMS

By Amir Safaei Pirooz, Richard Flay, Richard Turner, Paul Carpenter, Peter Cenek and Neil Jamieson WEATHER FLOOD COASTAL 23

Fig. 1. Time series from 1968 to August 2018 of insured losses (inflation Fig. 2. (a) Design wind adjusted to 2017 NZD) related to storm events where wind damage speed contour map was a major factor (i.e. not counting storm events where losses were and wind regions; primarily due to flood or coastal erosion) contributing to losses. (b) Lee zone regions.

New Zealand’s position in VARIATIONS FOR THE WIND-LOADING STANDARD In this collaborative project involving the the ‘Roaring Forties’ makes University of Auckland, NIWA and WSP- it vulnerable to extreme Opus, New Zealand’s historical wind speed data over the past two years have been weather and wind hazards, analysed for the purpose of revising design with many population wind speeds, and directional and lee-zone multipliers for the next version of the wind- centres and infrastructure loading standard. assets located in exposed Based on our findings, several substantial changes have been proposed for AS/ coastal or hilly areas. NZS1170.2, including adding a new region consisting of the Foveaux Strait area, Extreme wind hazards have a substantial refinements of wind zone boundaries, and societal and environmental impact. revising all directional and lee-zone multipliers. With climate change, it is expected that extreme weather and windstorms will Fig. 2a Shows a preliminary contour map of occur more frequently. design wind speeds for a 500-year return period, and the new wind regions. Fig. 2b When evaluated over time the insured Illustrates the revised lee zones proposed damages and losses are considerable. In for the next version of wind-loading standard CONTACT: the last decade, the total insured losses for AS/NZS1170.2. extreme wind events in New Zealand was Richard Flay about $1 billion NZD (Fig. 1). Currently, wind data from additional stations University of Auckland are being analysed to enhance the spatial E-mail: [email protected] All buildings and structures in New Zealand resolution of the regional wind speed map. are designed to resist the effects of the We are also using the data to investigate the Peter Cenek wind speeds specified in the wind-loading possible effects of climate change on the WSP Opus standard AS/NZS1170.2 (2011). Much of the long-term trends in extreme winds for design E-mail: [email protected] content of this standard has been prepared wind speed purposes. by a joint Australia/New Zealand committee. Affiliations However, New Zealand’s wind data have not Annual and seasonal trends in both the University of Auckland: Amir Safaei Pirooz been re-evaluated for purposes of updating magnitudes and frequencies of the extreme NIWA: Richard Turner the standard for the last 20 years. winds are being evaluated. This is to WSP Opus: Paul Carpenter, Neil Jamieson determine whether or not the long-term wind Most wind loading design applications are gust series have changed significantly. We concerned with the strongest winds expected will also look at how these changes can be in the lifetime of a structure. The establishment considered in the estimation of design wind of appropriate design wind speeds is a critical speeds to ensure the safety and reliability of first step towards the calculation of design future structures. wind loads for structures. 24 NATURAL HAZARDS | 2018

SOCIETAL RESILIENCE 25

Clockwise beginning Top: Kaiko-ura branch of the Red Cross preparing parcels. Photo: New Zealand Red Cross; Tsunami blue lines. Photo GNS Science. GNS scientist addresses town hall following Cook Strait-Lake Grassmere earthquake. Photo: Derek Flynn, Marlborough Express; Social scientist Julia Becker. Photo: GNS Science. 26 NATURAL HAZARDS | 2018 10 YEARS SOCIETAL RESILIENCE RESEARCH AND ITS IMPACT OVER THE PAST DECADE

In a post-Canterbury and Kaiko-ura earthquake context, we understand more about how to effectively respond By Julia Becker and recover, including for iwi and Ma-ori stakeholders, and David Johnston communities, organisations, tourism, and from an economic perspective. Earthquake, tsunami and The NHRP Canterbury earthquake recovery programme contributed funding to the CERA* Wellbeing Index and weather-related events Survey. This body of work assisted in understanding recovery needs over time, and how to best design over the last ten years have interventions to increase wellbeing. In 2014, Government highlighted New Zealand’s allocated an additional $13.5 million for psychosocial services as a result of on-going need identified by the vulnerability to natural Survey, with similar provision of services following the - hazards and have prompted Cook Strait and Kaikoura earthquakes (1). The Canterbury Wellbeing Index and Survey (as renamed important societal research. in 2016) was globally leading in developing post-disaster The merging of social recovery indicators, and contributed to international recovery knowledge. Following the disestablishment of science with geophysical CERA, the survey continued under the Canterbury District Health Board. More details can be found here: https:// and engineering studies www.cph.co.nz/your-health/wellbeing-survey/ has improved how we The Canterbury earthquakes also highlighted the communicate with the public pivotal role provided by Iwi and Ma-ori stakeholders in recovery efforts, repeated during Kaiko-ura. Marae were about natural hazards, operationalised as recovery assistance centres, where and provided insights into food and shelter were provided for those in need. Lessons learned have relevance for regional and emergency psycho-social recovery. management planning across New Zealand (2). SOCIETAL RESILIENCE 27

New Zealand research teams have also are fully prepared for a tsunami, leading to (1) Morgan, J. et al (2015) Monitoring wellbeing studied the actions of people during and the launch of the ‘Tsunami Safer Schools’ during recovery from the 2010-2011 Canterbury after earthquakes which influences their risk project by MCDEM in 2017. earthquakes: The CERA wellbeing survey. International Journal of Disaster Risk Reduction, of injury or death. Implications for assessing 14, pp. 96-103. crowd behaviour also exist, particularly Research on risk reduction and preparedness has highlighted important lessons for understanding the interactions between (2) Kenney, C.M., Phibbs, S. (2015) individuals such as how the actions/inactions individual households and communities, - A Maori love story: Community-led- disaster of an individual influence the actions/ and for institutional and government management in response to the Otautahi inactions of another (3). preparedness. A key aspect of preparedness (Christchurch) earthquakes as a framework for requires engaging with communities to grow action. International Journal of Disaster Risk The Ministry of Civil Defence & Emergency their understanding of hazards and build Reduction, 14, pp. 46-55. Management (MCDEM) ‘ShakeOut’ drill resilience. has been regularly run to assist people (3) Lambie, E.S. et al (2017) Closed circuit television in protecting themselves during future An example of a successful project for (CCTV) earthquake behaviour coding methodology: analysis of Christchurch Public Hospital video data earthquakes. Research has investigated the engaging with the community is the ‘I can live with this’ research project. This project from the 22 February Christchurch earthquake effectiveness of the ShakeOut campaign. event. Natural Hazards, 86 (3), pp. 1175-1192. It found that it encourages participants to sought to elicit local perspectives in the Bay of Plenty about tolerable and intolerable risks, take protective action during an earthquake (4) Fraser, S.A. et al (2016) Tsunami response and enhances preparedness. MCDEM has and build these into the land-use planning behaviour during and following two local- also used the research findings to adjust process for natural hazards. The Bay of Plenty source earthquakes in Wellington, New Zealand. the ShakeOut programme for greater example is being used as a case study for International Journal of Disaster Risk Reduction, 16, pp. 123-133. effectiveness. other local authorities to guide their land-use planning practices (5). Tsunami research has highlighted challenges (5) Kilvington, M., Saunders, W. (2019) Gaining public input on natural hazard risk and land-use in the public’s response to tsunami, with CONTACT: planning: A case study from New Zealand. Disaster people undertaking slow and partial Julia Becker Prevention and Management: An International evacuation after earthquake ground shaking Journal, 28 (2), pp. 228-244. (4). In response to these challenges, and Joint Centre for Disaster Research, Massey based on research on warning system University NHRP Theme Leader, Societal Resilience effectiveness, we have seen several new David Johnston (left) (2015-19) initiatives. These include the development and Julia Becker (right). of new tsunami evacuation maps, the ‘Long E-mail: [email protected] Photo: Catherine Pinal, or Strong Get Gone’ public education GNS Science. David Johnston campaign, rapid public alerting to mobile phones (Emergency Mobile Alerts, MCDEM Joint Centre for Disaster Research, Massey 2017), effective short warning messages, University and practical recommendations for vertical NHRP Theme Leader, Societal Resilience evacuation for tsunami. (2009-15) E-mail: [email protected] Research on tsunami preparedness in schools has also revealed that not all at-risk schools *CERA, Canterbury Earthquake Recovery Authority (2011-16). 28 NATURAL HAZARDS | 2018

By Kate Boersen, Lucy Kaiser, and William Power SOCIETAL RESILIENCE 29

Community workshops in Napier. Photo: Kate Boersen, ECLAB.

Community workshops in Napier. Photo: Kate Boersen, ECLAB.

Researchers from GNS usefulness and helped identify the most that would not be accessible in real life, valuable case study locations for future civil as well as alternative routes that could be Science, Massey University, defence emergency management planning. used. Participants also identified potential solutions to make tsunami evacuations East Coast LAB (Life at the This engagement has continued throughout easier, safer and quicker. the process, from the co-development of Boundary), and University workshops to the refinement of the final Participation has varied across locations with of Canterbury have been models developed by GNS Science. between 10 and 115 people attending the workshops. The information that participants working with emergency RELYING ON LOCAL KNOWLEDGE identify will be passed on to emergency managers and it is also intended that the final managers, council staff and Project Leader William Power (GNS Science) evacuation models will be shared with the local communities to develop said that the research team recognised civil defence emergency groups in the three early on that they needed to incorporate case study areas. and refine computer-based information in the models that only the locals knew (such as congestion points and CONTACT tsunami evacuation models. unmapped pathways). They decided the best William Power The models are based on simulations of way to tap into this knowledge was to hold the tsunami evacuation paths taken by community workshops. GNS Science E-mail: [email protected] people in the event of a long or strong The workshops were designed with the earthquake. The project focuses on suburbs community at its centre, with day and evening Affiliations in Wellington, Napier and Christchurch. hours to suit busy schedules and disability East Coast LAB (Life on the Boundary): Kate Validation of the model using GPS tracking access available at chosen venues. Workshops of volunteers practising evacuations is also Boersen have been held in Wellington, Napier and GNS Science/Massey University: Lucy Kaiser being undertaken. Christchurch. Early engagement with emergency Participants were introduced to the project management- and council staff during the Photo: Julian Thomson, before the workshop began. They helped GNS Science. development of the project validated its to identify routes presented in the model 30 NATURAL HAZARDS | 2018

ADAPTIVE AND INTERACTIVE FUTURES: A SERIOUS GAME FOR DECISION-MAKING AND COASTAL HAZARDS SOCIETAL RESILIENCE 31

By Paula Blackett, Kate Davies, Paula Holland, Ben Davies and Nick Cradock-Henry

Computer-based ‘serious games’ allow players to explore 1 complex and contested issues. In this project exploring coastal adaptation to climate change, researchers have tested the concept with the public.

In this project we are developing a ‘serious • The concept of a game as an engagement game’ that will empower communities and tool was well received, and the players individuals with new knowledge to decide became engrossed in the game. and act regarding coastal adaptation to climate change. • Many found making choices difficult and agonised over how to balance the interests 2 For the game to be relatable to the players, it of the different characters. needs to present a plausible and interesting scenario based on realistic adaptation options • Players felt the game represented their and community reactions. In this case, the experiences of coastal climate change player enters the game as the decision- adaptation, albeit with less detail, but in maker for a New Zealand coastal community a more abstract and simplified setting. faced with increasing inundation and coastal Based on this feedback we are working on erosion due to climate-driven sea level rise. further character development, improving the Their task is to work with the community, visual experience and refining the interactions represented by six ‘non-player’ characters, to between finances and popularity. Once enable adaptation to changing risk from sea completed, in November 2019, the game level rise over 100 years. will be freely available. It takes about 10-20 Over the course of the game, coastal erosion minutes to play. We thank Monica Pooley for and inundation will impact many of the providing the game illustrations. 3 elements valued by this community such If you are interested in helping test the next as the beach, homes and local businesses. version of the game, please contact us. How quickly these impacts occur depends on which scenario is randomly selected CONTACT: at the start of the game. To simulate decision-making under deep uncertainty, Paula Blackett no information is presented on the pace of NIWA change. It is revealed as the game evolves – E-mail: [email protected] much like a real-life situation! Affiliations The player has several adaptation options NIWA: Kate Davies and Paula Holland they can apply (e.g. beach re-nourishment, Davies Environmental: Ben Davies building sea-walls) provided they can afford Manaaki Whenua – Landcare Research: Nick them. Each option has advantages and Cradock-Henry 4 disadvantages, as well as a lifespan related to sea level. This is complicated by non-player Serious game illustrations by Monica Pooley. preferences for different options, and certain actions can affect the players’ income (rates) and overall popularity. Player choices influence how non-player Storm on the Fig. 1. The player Wellington south coast. begins with this characters behave in subsequent rounds Photo: Dave Allen, community …. by shifting both their satisfaction with NIWA. Fig. 2. The community current conditions and their trust in decision- might experience makers. Non-player character responses damage to the park and are based on previous work by the research coastal foreshore. team, as well as research experiences from Fig. 3. The community adaptation debates. might choose to build a seawall…. In November 2018, we tested a prototype Fig. 4. … or relocate game at the New Zealand Coastal Society beach front homes Conference with 20 participants, including and shops. council staff, practitioners and researchers. Overall, responses to the game were positive and feedback suggested that: 32 NATURAL HAZARDS | 2018

RESILIENT ENGINEERING & INFRASTRUCTURE 33

Clockwise beginning Top, left: Structural interactions between walls and floors; Damage to unreinforced masonry following the Christchurch earthquake. Images: University of Auckland; Damage at CentrePort; Matthew Hughes with the Liquefaction Resistance Index map; Greg MacRae (right) and PhD student Jamaledin Borzouie. Photos: University of Canterbury. 34 NATURAL HAZARDS | 2018 10 YEARS ENGINEERING AND INFRASTRUCTURE RESEARCH

The Canterbury earthquakes signified a turning point for the building and infrastructure sector. For engineers, it was a heightened period of research to understand performance and damage profiles. For the public, it became an evolving awareness of the building code (life safety vs immediate occupancy), infrastructure functionality, and whether this matched with expectations.

At its start, the NHRP programme supported recommendations to achieve tolerable prone buildings. The issue remains underpinning research for ongoing studies impact levels with respect to building contentious with ongoing political and in unreinforced masonry, low damage functionality and safety at varying intensities economic discussion. technologies and non-structural elements. of earthquake hazard. The geotechnical work included field data and modelling Researchers have contributed to standards Following the Canterbury earthquakes, to understand soil-structure interactions, and guidelines utilised by the engineering effort was quickly diverted to investigating underground pipe networks, restoration profession. This includes an update of the performance of buildings (unreinforced times, damage costs, and impacts of Detailed Seismic Assessment Guidelines masonry, concrete, steel), non-structural mitigation measures. Research outcomes for concrete, steel, timber and URM elements, infrastructure and lifelines. were shared with recovery agencies, buildings, and development of Guidelines Extensive ground damage as a result of government and the engineering sector. for Earthquake Geotechnical Engineering liquefaction and lateral spreading was a Practice. Much of this work was informed critical issue, and a research programme The Canterbury programme was influential by the Canterbury experience. examining the impacts of liquefaction, soil in low damage technologies being profiles and triggering factors was initiated. introduced into some of the new construction The research team are also continuing in Christchurch, and to some extent their studies on residual capacity, which This research was an integral part of the was mirrored in Wellington following the is to understand the impact of prior NHRP Canterbury earthquake recovery Cook Strait-Lake Grassmere earthquakes. earthquake damage on a structure and programme, with NHRP engineers providing how this affects downstream performance technical reports and expert testimony to The risks related to unreinforced masonry in subsequent events. These studies were the Royal Commission, in addition to and options for retrofit were known. On 1 critical in the inspection of precast concrete seminars and workshops communicated July 2017, the Building (Earthquake-prone floors in Wellington buildings following the with the sector. Buildings) Amendment Act 2016 came into Kaiko-ura earthquakes. force modifying how local councils, Over the longer-term, research sought engineers and building owners are to carry improvements to design practices and out assessment and deal with earthquake- RESILIENT ENGINEERING AND INFRASTRUCTURE 35

IMPROVING THE DESIGN OF NEW BUILDINGS

By Rick Henry, Minghao Fig. 1. ILEE- QuakeCoRE low- Li, Chin-Long Lee, Greg damage concrete MacRae, and Charles Clifton building test. Photo: University of Auckland. 36 NATURAL HAZARDS | 2018

Fig. 2. Glulam It is critical that research into structural systems keeps up frame BRB test. Photo: University of with trends in current building practices, and that design Canterbury. standards and guidelines are updated.

Fig. 3. Bi-directional steel frame BRB testing. Trends in building construction are constantly An overstrength factor identified from these Photo: University of Canterbury. evolving as engineers adopt new systems and tests has now been included in the new incorporate lessons from past experience. draft of the timber design standard AS/NZS Previously popular reinforced concrete-frame 1720.1. A separate project is investigating buildings with precast floors are giving way to the use of heavy timber frames with BRBs. buildings that use stiffer braced steel frames or Two full-scale prototype glulam frames with concrete walls, composite floors, and a range common BRBs have been tested (See Fig. of new low-damage technologies. 2). These hybrid structures were designed as low-damage systems with glulam members A coordinated research programme within and connections protected by capacity design the Natural Hazards Research Platform has and BRBs providing the source of energy focused on assessing the seismic performance dissipation. In addition, a new type of BRB is and design of structural systems popular in being developed using a timber casing, with new buildings. These include concrete walls, initial testing providing promising results. steel buckling-restrained brace (BRB) systems, composite floors, and timber LVL, CLT and glulam.* The interactions between these STEEL BUILDING RESEARCH structural components have been considered For steel buildings, research has focused on with detailed modelling and large-scale the interaction of BRBs, gusset plates and their experimental testing. supporting frames. The test rig used to subject the BRB frames to bi-directional loading CONCRETE BUILDINGS EXAMINED demands is shown in Fig. 3. The experimental findings, and supporting numerical studies, For concrete buildings, the research has are being developed into simple and clear focused on wall design and provisions in the analytical methods. Concrete Structures Standard (NZS 3101) to account for whole-of-building response. The A separate project has focused on composite influence of wall-to-floor interactions has been floors and specifically the interface between assessed using detailed numerical models. composite floors and steel-framed seismic resisting systems. Building demands from Modelling results have shown that the time history analysis, considering floor inclusion of the floor stiffness and strength inertia forces and the forces caused by can significantly increase the axial and shear relative movement of framing systems were demands imposed on walls and columns, considered and compared with a number of compared to the demands estimated from proposed design methods. The capacity side simplified models used in design. In addition, has focussed on experimentally determining modelling of coupled wall systems has the strength and stiffness of common quantified the overstrength that occurs due composite floor diaphragm connections. to axial restraint from floor slabs adjacent to Design guidance has been developed and coupling beams. will be published shortly. The influence of load rate on reinforced concrete walls has been investigated with a CONTACT: series of tests on axially loaded prisms. The Rick Henry prism test results are being used to verify University of Auckland the dynamic load factors included in the NZS E-mail: [email protected] 3101 provisions for wall minimum vertical reinforcement. Lessons from the research Affiliations on wall-to-floor interactions were recently University of Canterbury: Minghao Li, included in large-scale shake-table tests of Chin-Long Lee and Greg MacRae low-damage concrete wall buildings as part University of Auckland: Charles Clifton of the collaboration between QuakeCore and the International Joint Research Laboratory of Earthquake Engineering (ILEE) at Tongji University in China. (See Fig. 1.)

*LVL, laminated veneer lumber; CLT, cross-laminated timber; TIMBER BUILDINGS INVESTIGATED Glulam, glue-laminated timber; BRB, buckling-restrained For timber buildings, the behaviour of dowel- braces. type connections used in new structures has For more information about timbers used in New Zealand been investigated with a series of large-scale construction, see an article by Jeff Parker (2015) Timber takes on new forms, Build Magazine, Issue 149, page 50-51 (Aug/ tests using timber LVL and CLT. Sept 2015). RESILIENT ENGINEERING AND INFRASTRUCTURE 37 38 NATURAL HAZARDS | 2018

RISK 39

Clockwise beginning Top, left: Rockfall following the Christchurch earthquake. Photo: GNS Science; Damage in Greymouth after ex- Tropical . Photo: NIWA; Building damage caused by the Christchurch earthquake. Photo: GNS Science; Damaged irrigators following Canterbury wind storm. Photo: NIWA. 40 NATURAL HAZARDS | 2018 10 YEARS PROGRESS IN RISK MODELLING IN THE ERA OF THE NATURAL HAZARDS RESEARCH PLATFORM

By Kelvin Berryman

When thinking about the JOINING UP THE RESEARCH RISK MODELLING ON THE RISE Step forward to 2009 and the beginning Fast forward to the end of the NHRP era progress in New Zealand of the era of the Natural Hazards Research in 2019 and risk modelling continues to risk modelling, it is useful to Platform. The joining of natural hazards gather momentum. Multiple runs of risk research with the built environment research models with alternative fragility attributes go back a few years prior to brought together the components of the risk of the built environment can illustrate the the formation of the Natural formulation – hazard and assets – and their value of retrofit in reducing future losses fragility at varying levels of hazard severity. and disruption of communities. Hazards Research Platform There were also more players in the risk field. Risk modelling is at the core of many science in 2009. Catastrophe modelling in the insurance programmes and projects. However, the sector, and the Global Earthquake Model research and user community must continue You could say that a major step forward in (GEM) initiative founded in 2009 sought to evolve the methods and tools. Disruptive New Zealand risk modelling began in 2004 to reconfigure the earthquake problem technologies, such as machine learning, more with the start of RiskScape, taking us from from a hazard narrative to that of risk, with complex numerical simulation capabilities; a hazards-centric point of view to the world consideration of consequences and impacts. rapidly changing asset characteristics, such of risk. as aging infrastructure and demographic In addition, engagement between scientists And ‘risky’ it was. There was no business shift; and the desire to expand the range of and the local government sector was plan and access to key asset data, such as visualisation approaches to communicate beginning to gather momentum with value infrastructure and built environment, was risk, all need to be addressed. being attached to sharing the fundamental limited or non-existent. A great deal of effort asset data. This meant that when delivered was expended in the early days to gather the CONTACT: back to the infrastructure or building owner, fundamental data. I would suggest there was the added value was understood and Kelvin Berryman too little attention paid to user needs – the appreciated. Director, Natural Hazards Research Platform pressure was on to deliver tangible results (2009-2015) before really understanding ‘for whom, why GNS Science and what’. E-mail: [email protected] RISK 41

RISKSCAPE 2.0 – WHAT IS COMING NEXT?

The impact of the risk modelling tool RiskScape is growing, By Richard Woods with the Earthquake Commission recently joining GNS Science and NIWA to further develop the tool for New Zealand.

New Zealand is vulnerable to many natural RISKSCAPE VERSION 2.0 hazards including floods, tsunami, volcanoes and earthquakes. Measures can be taken to reduce the risk to lives and livelihoods, but first RiskScape Ecosystem it is necessary to understand the likely location and intensity of these hazards’ impacts. RiskScape is risk modelling software

developed jointly by NIWA and GNS Science Local FilesD sDefault GUI since 2004. It quantitatively estimates the impacts of natural hazard events, identifying where the highest risks to people, buildings and infrastructure damage may occur. It’s a valuable tool for land-use planners, emergency managers, engineers and insurers. Externally Developed ENGINE GUI A new collaboration with the Earthquake Asset / Hazard Commission (EQC) will see RiskScape Database 2.0 replace the Commission’s current risk modelling software. It will be used to produce earthquake loss and impact estimates and will inform EQC’s annual reinsurance negotiations. Our three organisations will continue to invest in the development of External RiskScape 2.0, including assessing other Database geological and weather-related hazards. RiACT Vulnerability The New Zealand Treasury and the insurance Database sector are also using the tool for major projects to forecast future losses and impacts. However, interest is not restricted to New potential mitigation options. Beginning with Zealand shores with the World Bank Group pilot studies in Westport, Hawkes Bay and and NASA showing keen interest in RiskScape. Christchurch, RiskScape is now being used by the Samoa and governments, REDEVELOPING THE TOOL through the Pacific Risk Tool for Resilience From May 2018, RiskScape has been (PARTneR) project, and in some Indonesian under redevelopment using open source universities. technology to build a new modular In New Zealand, RiskScape has underpinned adaptive platform. The work programme for loss estimates for the AF8 research RiskScape includes continuing to develop programme and has evaluated the impacts of its core engine, with a focus on workflow a large Wellington earthquake, in partnership functionality, optimisation and performance with the MeRit Tool (Measuring the enhancements. Starting in late 2019, a Economics of Resilient Infrastructure). customised user interface will be built using specific requirements from the vast array of CONTACT users. Richard Woods Since its initial development, RiskScape has GNS Science been used domestically and overseas to learn E-mail: [email protected] more about natural hazards and evaluate The 2018 Mw 7.5 Sulawesi earthquake and tsunami destroyed many buildings and caused more The ruins of what was previously known as than 1700 fatalities in Palu City, the “floating mosque” of Palu. The mosque Sulawesi, Indonesia. A New Zealand was a raised building in a body of water and field team accompanied Indonesian supported by piles. colleagues to observe and record Photo: RiskScape tsunami damage to buildings, roads and electricity infrastructure in By Ryan Paulik, James Williams, Palu City from the event. Aditya Gusman and Sheng-Lin Lin RISK 43

The field team comprised researchers component damage was observed for Sulawesi earthquake and tsunami special from NIWA, GNS Science and the University engineered ‘reinforced concrete’ buildings. edition of Pure and Applied Geophysics. of Canterbury. Coastal roads were frequently damaged We would like to acknowledge the StIRRRD We measured tsunami flow depths up to at culvert sites and utility poles sustained programme – ‘Strengthened Indonesian 3.65 metres at 371 building sites and recorded complete damage from debris impact or Resilience: Reducing Risk from Disasters’ – the attributes and damage levels for 463 scouring. These observations are consistent which made our participation possible. buildings, 7.9 km of road and 455 utility poles. with damage recorded by New Zealand researchers in Coquimbo, following the 2015 CONTACT We observed that non-engineered ‘light earthquake and tsunami in Illapel, Chile. timber’ and ‘lightly reinforced concrete’ Ryan Paulik buildings were highly susceptible to non- The information collected in Palu City NIWA structural component damage when tsunami contributes to an important evidence base E-mail: [email protected] flow depths exceeded 0.4 metres (for light for future tsunami hazard and risk research timber) and 1 metre (for lightly reinforced that informs activities to minimise damage Affiliations concrete) above building first floor levels. and loss of life from future tsunami events. University of Canterbury: James Williams GNS Science: Aditya Gusman Unrepairable or complete damage was With our colleagues we have published our and Sheng-Lin Lin regularly observed when flow depths survey activities and findings in the 2018 exceeded 1.2 metres. Only non-structural 44 NATURAL HAZARDS | 2018

RESILIENCE TO NATURE’S CHALLENGES 45

Clockwise beginning Top, left: Scientists Rob Bell, Ellie Kay and Wendy Saunders. Photo: GNS Science; Outreach in Kaiko- ura; RNC Trajectories researchers. Photo: Resilient Organisations; Haumoana, part of the ‘Living on the Edge’ programme. Photo: NIWA. 46 NATURAL HAZARDS | 2018

TOWARDS RESILIENCE SOLUTIONS FOR RURAL REGIONS

Earthquakes, floods, snowstorms, and and opportunity assessment, operational the effects of climate change present planning, and decision-making. Co-creation By Nick Cradock-Henry, unique challenges for the well-being of refers to ways in which researchers, policy- Joanna Fountain, and rural Aotearoa New Zealand. Preparing makers and practitioners can generate Tom Wilson for and responding to these and other new knowledge together to address societal risks is compounded by the exposure of challenges. Over the last four years, the critical infrastructure and lifelines, and Rural team and its co-creation partners From response through local economies dependent on the free have been working in Kaiko- ura with civil movement of goods, services and people. defence, tourism stakeholders, and local to recovery, researchers Disasters however, can also be catalysts for and central government agencies, exploring are working together change. By disrupting existing conditions innovative approaches to building resilience, or circumstances, disasters can create documenting lessons and experiences, with policy-makers and opportunities to critically evaluate risks and and developing tools which can be practitioners to advance explore pathways to greater resilience for used elsewhere. local communities. resilience solutions for rural Pre- and post-quake, the Rural team has Located on the east coast of the South worked to foster co-productive relationships, Aotearoa New Zealand. Island, Kaiko- ura is small community of particularly with the Ministry for Primary 2000 people, with 1500 more in the Industries (MPI). By providing data and surrounding district. The local economy leveraging science investment, the team is dependent on primary industries and has been able to develop new pathways tourism. Furthermore, it is exposed to a for rural resilience and extend existing range of hazards, including earthquake, research into additional projects with MPI’s wildfire, tsunami and landslide risks, typical investment support. of rural regions throughout Aotearoa. The 2016 earthquake drew attention to the Just after midnight on 14 November 2016, vulnerability of farm businesses and their a magnitude 7.8 earthquake began near role in sustainable land and biodiversity. Culverden, south of Kaiko- ura, and came to a Through MPI funding to Beef and Lamb stop near Seddon, ninety kilometres north, NZ, Jo Fountain (Lincoln University) and rupturing across multiple fault lines. The Environment Canterbury’s Michael Bennett two minutes of shaking raised the coastline are working with North Canterbury livestock several metres in places, tearing through farmers to build resilience through economic road and rail networks. Along State Highway diversification and storytelling. By developing 1, thousands of landslides, slips and surface additional revenue sources, farmers may be deformation cut off critical road access, better prepared for economic shocks, and while across the region, there was extensive through telling stories of people, place and damage to homes and buildings. provenance, create additional value and brand loyalty. The following morning as the damage became clear, a concerted response effort Another co-creation project funded by MPI was mobilised, led by Civil Defence and is focusing on earthquake vulnerability and Emergency Management and others with New Zealand’s fast-growing wine industry, contributions from the scientific community. with case studies in the Waipara Valley, North Road damage near Clarence caused by This collaborative effort has continued to Canterbury and Marlborough. The project the 2016 Kaiko-ura grow and develop. team led by Nick Cradock-Henry (Manaaki earthquake. Photo: Whenua Landcare Research) involves a The Rural Co-Creation Laboratory – part Julian Thomson, diverse team of social scientists, engineers, GNS Science. of the Resilience to Nature’s Challenges and industry partners including Fountain, National Science Challenge – has been Jason Ingham (University of Auckland), and working with stakeholders to develop Ed Massey (NZ Winegrowers). Taking a value applied resilience research to inform risk chain perspective, the research is focusing on RESILIENCE TO NATURE’S CHALLENGES 47

the structural, social and economic impacts of earthquakes, from the vineyard through to Grapes growing near Rupture on the Papatea processing, transportation and distribution. Seddon are essential fault through farmland to New Zealand’s and across roads The engineering team has recently developed rapidly growing wine following the 2016 the world’s largest database of impacts on industry. Photo: Nick Kaiko-ura earthquake. wine storage tanks, and is now using data to Cradock-Henry. Photo: Dougal Townsend, improve tank design. A new paper* by the GNS Science. social-science team explores how resilience is shaped within the broader context of other risks, and influenced by size and scale of operations. The resilience framework is now being extended to work on supporting climate change adaptation in the industry. Over the past five years the Rural programme has developed these and other aligned projects to better understand the impacts and implications of different stressors. Partnering with policy-makers and practitioners from across the primary sector and rural economy, this new mode of working together is generating useful and usable knowledge. Looking ahead to the next five years CONTACT: of the Resilience Challenge, these efforts will be extended with projects aimed Nick Cradock-Henry at strengthening agri-food and tourism Manaaki Whenua – Landcare Research networks, enhancing value-chain resilience, E-mail: and exploring the effectiveness of policy [email protected] interventions. The Rural programme will continue to engage and co-create Affiliations new knowledge with research and industry Lincoln University: Joanna Fountain partners to inform preparedness and University of Canterbury: Tom Wilson recovery planning elsewhere, and generate rich examples of the ways in which disasters can create opportunities for resilient rural futures. Top: University of Bottom: Wineries in Auckland PhD student, Marlborough sustained Mohsen Yazdanian damage to storage tanks, *Cradock-Henry, N.A., Fountain, J. (2019) Characterising inspecting damaged catwalks and piping resilience in the wine industry: Insights and evidence from wine tanks in the systems. Dmytro Dizhur Marlborough, New Zealand. Environmental Science and Marlborough following and team records damage Policy, 94, pp. 182-190. the 2016 Kaiko-ura data for input into models earthquake. Photo: and for improving design Dmytro Dizhur. considerations. Photo: Mohsen Yazdanian. 48 NATURAL HAZARDS | 2018

THE NEW ZEALAND RESILIENCE INDEX AND MEASURING RESILIENCE

Monitoring and evaluation is an important part of New By Ellie Kay, Chris Bowie Zealand’s new National Disaster Resilience Strategy. But how and Vivienne Ivory do you measure a seemingly abstract concept like resilience? RESILIENCE TO NATURE’S CHALLENGES 49

Through the Resilience to Nature’s Challenges a localised resilience assessment for the CONTACT: National Science Challenge, researchers from Wellington region. For example, the locations Resilient Organisations and WSP Opus have of earthquake-prone commercial buildings Ellie Kay developed the New Zealand Resilience Index were added to the index, providing additional Resilient Organisations (NZRI). This is a composite indicator* that understanding of resilience in the Built E-mail: [email protected] assesses the resilience of the country’s place- capital. By including data collected during based communities over time. ‘business-as-usual’ activities, it enabled us to Affiliations align the resilience measurement with existing WSP Opus: Chris Bowie and Vivienne Ivory The index uses the multi-capital model that local and regional planning. underpins the National Disaster Resilience Strategy (Fig. 1). Comprised of indicators There are future opportunities to further * A composite indicator combines multiple indicators into a single measure, allowing for the capture of the across the six capitals, the NZRI provides our ability to measure, and therefore multi-dimensional nature of resilience while simultaneously users with a mechanism to evaluate understand, holistic resilience. As well as simplifying a complex concept. community resilience over time and to inform augmentation of the national NZRI through Indicators Aotearoa New Zealand is being developed resilience intervention decision-making. increasing data availability (i.e., through by Statistics New Zealand as a source of measures for New programmes like Indicators Aotearoa) and Zealand’s wellbeing. The set of indicators will go beyond economic measures, such as gross domestic product (GDP), The NZRI can be used at both national and regional augmentation of the index, there regional level. At national level, the current to include wellbeing and sustainable development. are opportunities to enhance our ability to Visit www.stats.govt.nz for more information. 13-indicator NZRI is limited to publicly collect primary (survey) data to better inform available, nationally-consistent data. A the index. The research team are currently further 53 resilience concepts could be exploring the development of an agile added if data were routinely collected. surveying tool that can assess community Over time, initiatives such as the Indicators resilience capabilities, as well as engaging Aotearoa programme, will help to fill missing communities in resilience decision-making. data gaps within the NZRI. The NZRI complements the National Disaster At regional level, there is an opportunity to Resilience Strategy as a method of measuring apply and expand the NZRI to cover a wider progress towards the vision of New Zealand range of resilience concepts. The research as a disaster resilient nation. It also provides team worked with the Wellington Regional a mechanism to proactively manage risk and Emergency Management Office to identify build resilience to improve the wellbeing and datasets that could be repurposed to develop prosperity of New Zealand. Read more about this project in our full Researchers reviewing Fig. 1. The New report available at www.resorgs.org.nz: the National Disaster Zealand Resilience ‘The Resilience Warrant of Fitness Research Resilience Strategy. Index uses the multi- Programme: Towards a method for applying capital framework of Photo: Resilient the New Zealand Resilience Index in a Organisations. the National Disaster Resilience Strategy. regional context.’ 50 NATURAL HAZARDS | 2018

RESILIENCE TO NATURE’S CHALLENGES LOOKING AHEAD: 2019 TO 2024

By Richard Smith

In November 2018, the MBIE For the last six months we have been busy This is a time of significant change in how developing the research leadership team, we will work and organise ourselves, with new Science Board approved the and turning the high-level intent into more governance and leadership roles coming on detailed research plans for the ten research board. We are also looking to develop next five years of funding themes. The shape and scope of these a new strategic leadership team to support for the Resilience Challenge themes reflect the inputs and advice of the Director, with responsibilities for stakeholders over the last 18 months, and integration of Vision Ma-tauranga, science (RNC). The high-level research extends many of the strong workstreams in linkages across the ten research themes, and rural, urban, Ma-tauranga Ma-ori, coastal and coordinated approaches for research co- plan draws extensively on the infrastructure resilience. development and partnerships. Stand by for successful ten years of the a call for Expressions of Interest in the next Over the next five years, these workstreams two months. Natural Hazards Research will be accompanied by exciting new research to advance our understanding of Key to success of the next five years will be Platform, and integrates the natural hazard processes such as wildfire, not only excellence in science, and effective earthquakes, tsunami, landslides, volcanoes collaboration across the science system, but research capability and key and high-impact weather. And it will include also how effectively we can partner with the partnerships from phase one a strong push for developing potentially users of the research. We need to ensure the transformative Multi-hazard Risk methods. RNC’s outputs can be easily taken up and of the RNC, into phase two applied to influence changes in behaviour, This improved quantitative view of our practice and policies. (2019-24). disaster risks will be strongly paired with social, economic and cultural research To this end, we have developed a revised to develop tools and methods to build Outcomes Framework which will steer our Resilience into Practice (and policy) across priorities and efforts. New Zealand’s public, private and built environment sectors. RESILIENCE TO NATURE’S CHALLENGES 51

While we have defined the overall research scope, we are still developing the approach to working on many key research questions and issues, and how best to communicate, connect, and partner to ensure successful co-production. For some of the research themes, this will involve building on existing mechanisms that are working well. For others, new arrangements and approaches may be needed, including how we involve different groups of stakeholders at different stages of projects and at different levels of the overall Themes and Challenge. This work will be a key focus over the next 6-12 months. We look forward to working with you to make the most of this opportunity.

CONTACT Richard Smith Director, Resilience to Nature’s Challenges GNS Science E-mail: [email protected] 52 NATURAL HAZARDS | 2018

EARTHQUAKES TSUNAMI HIGH TEMPERATURE In 2018, GeoNet recorded 19,472 earthquakes 2018 was a relatively quiet year for tsunami 2018 was New Zealand’s second-equal in New Zealand – which is around the annual activity in the Pacific. At the start of the year warmest year on record, according to average of about 20,000. Thirty of these on 23 January, a M7.9 earthquake in Alaska NIWA’s Seven Station Temperature Series earthquakes were magnitude 5.0 or greater, prompted the Ministry of Civil Defence and which begins in 1909, while January 2018 with the most significant of these being a Emergency Management to issue a warning was the hottest single month on record for M6.2 earthquake 207 km below Taumarunui for potential strong currents and surges in New Zealand. on 30 October. There was a M6.7 earthquake New Zealand. This was later withdrawn as just inside the New Zealand network interest more data became available. Alexandra reached 38.7°C on 30 January in the Kermadec region on 10 September, at – New Zealand’s 12th highest temperature a depth of 126 km – this was not as widely felt On 5 December, some small observations of on record overall and 3rd warmest January as the Taumarunui earthquake. tidal activity were noted on our tide gauges temperature on record. This was New from a M7.6 Loyalty Islands earthquake. Zealand’s hottest temperature for 2018. This could be considered a quiet year for Scientists assessed whether the earthquake seismic activity in New Zealand, with no created a tsunami that could affect New Overall, this was New Zealand’s warmest damaging earthquakes occurring. Zealand, which resulted in a ‘no threat’ summer on record (for the period December notice being issued. 2017-February 2018). This was in part due to air temperatures being warmed by the Tasman Sea marine heatwave, which lasted from November 2017 to March 2018. NATURAL A BRIEF SNAPSHOT OF THE

COASTAL HAZARDS in the Nelson/Tasman area with an average VOLCANIC HAZARDS recurrence interval of 110-170 years. On 5-6 January 2018, a low-pressure system 2018 was a quiet year for volcanic activity of subtropical origin deepened near New On 20-21 February, ex-tropical in New Zealand. Currently the Volcanic Alert Zealand, generating strong north to north- approached central New Zealand from the Level for two of New Zealand’s cones are at east winds in the Upper North Island. The Tasman Sea, bringing large swells to the west Level 1. These are Whakaari/White Island - wind generated waves, which when combined coast – particularly the Taranaki to Kapiti coast, off the Bay of Plenty Coast, and Mt Ruapehu with storm surge and the highest high tide of overtopping and damaging seawalls and SH1, in the Tongariro National Park, both showing the year, led to widespread coastal flooding before crossing the country and impacting signs of volcanic unrest. All the remaining and damage, with severe damage to the the Canterbury coast. The Banks Peninsula cone volcanoes and caldera volcanoes Thames-Coromandel state highway. The wave buoy recorded its largest significant remain quiet, in addition to the Auckland storm-tide level at the Tararu gauge in the wave height for the year of 6.52 m (period 11.1 Volcanic Field. Firth of Thames reached its highest water secs) early on 21 February, with a maximum level (2.86 m) on 5 January since the gauge individual wave height, of 11.4 m following Following the eruptions in 2016, little was commissioned in 1990, resulting in a 3.0 slightly later. It is estimated insured losses from has happened at Whakaari/White Island. m water level at the shoreline (an average this event were $35.6M nationwide. However, by March a crater lake was starting recurrence interval of 100 years). to form and fill on the floor of the active In the Southern Ocean, a wave buoy deployed crater. In 2018 the temperature of the crater On 1-3 February, ex- Fehi by MetOcean Solutions and the New Zealand lake at Ruapehu was quite variable and impacted the northern part of the South Navy near Campbell Island recorded a 23.8 became ‘stuck’ at about 30 °C in the later Island and the West Coast with wave m wave at 00:00 NZST on 9 May 2018. This is portion of the year. overtopping and coastal flooding, with believed to be the largest ever wave height significant damage to coastal roads and recorded in the Southern Hemisphere. In July, a small hydrothermal eruption housing and $45.9M insured losses. The occurred at Waiotapu with no impact to joint probability of storm surge (0.43 m), people. About 5-6 cubic metres of mud wave setup/runup at the coast and a high was ejected. perigean-spring tide produced a water level 53

LOW TEMPERATURE WIND & TORNADOES The 10 April event was noteworthy in that the for the directions experienced in this storm, On 10-11 April, an active front moving north The passage of two powerful ex-tropical West and Northwest, the average recurrence across the country brought in very cold air, cyclones, Fehi and Gita in February ($46 intervals (ARI) were at least 5-10 years for all resulting in numerous low daily maximum million and $36 million in insured losses, wind recording sites across Auckland and temperature records for the month of April. respectively) and a severe wind event hitting greater than 20 years for around half the the Auckland region on 10 April ($75 million) At the end of May, an inversion and persistent recording sites. Damage to trees and power were the notable New Zealand wind events distribution was extensive and power outages low cloud trapped cold air at the earth’s of 2018. surface throughout Central Otago, resulting lasted several days in many locations. in low daytime maximum temperatures for 2018 was unusual in terms of ex-tropical Tornadoes were reported on 5 days with many locations. On 31 May, Lauder only cyclone activity and impact on NZ in several damage caused at Rahotu-, Taranaki, National reached a maximum temperature of -2.6°C, respects, including (i) the number of events – Park, and Auckland (Swansons Railway) on 10 which was a new May record with data going 3 ex TC compared to the long-term average April, Matamata on 18 June, New Plymouth back to 1924. of around 0.7 for the period 1960 to 2018; and Ohope on 20 August, Ruakura on 29 (ii) the number of events crossing the South October, and Ashburton on 18 November. The lowest air temperature of 2018 was -10.4°C Island (2 compared to the long-term average recorded at Mt Cook (Airport) on 3 June. of 0.2); (iii) intensity; Fehi ranked 3rd equal For more on damaging wind events in New and Gita 6th in terms of central pressures, Zealand in 2018, see the “Strong Winds” and (iv) the early dates of occurrence. Both section of NIWA’s annual climate summary: Fehi and Gita caused damaging coastal https://www.niwa.co.nz/climate/summaries/ inundation, widespread tree and building annual-climate-summary-2018. damage and power outages. HAZARDS MAIN EVENTS OF 2018

LANDSLIDES Tasman, Kaiko-ura and Gisborne areas. SNOW, HAIL & ELECTRICAL STORMS This is the reason our total number of Landslides have continued to impact landslides is high this year and indicates that On 6 August, a large avalanche occurred New Zealand communities. The landslides we probably miss thousands of landslides on the upper slopes of Turoa ski field on Mt we know of are those that are reported in the most years because they are neither reported Ruapehu, damaging the High Noon Express media or are in populated areas, many others nor recorded. chairlift. The damage was significant enough may go undetected. Much of the landslide that the chairlift was unable to be used for the activity in the past year was triggered by In late February, a large landslide blocked remainder of the ski season. extreme rainfall events. the Mangapoike River in Wairoa, causing a landslide dam lake. There was also a large On 17 September, a cold front moved over In 2018, we recorded 10,095 small landslides debris avalanche (about 200,000 cubic the South Island bringing heavy rain and (<1,000 cubic metres), 37 medium landslides meters) off Craig Peak, near Fox Glacier snow, particularly to Central Otago and (1,000-10,000 cubic metres), and 4 large in August. One person died as a result of parts of Southland. Schools in Queenstown, landslides (>10,000 cubic metres). rockfall on SH4 at Raukawa falls. There were Arrowtown, and Te Anau Basin closed for the day. Queenstown Airport cancelled more Most of the landslides were triggered in no reports of injuries. than 30 flights due to snow. the Tasman and Kaiko-ura areas by ex-tropical Cyclone Gita (about 2000 landslides) in February, and by the Queen’s Birthday storm LOW RAIN & DROUGHT HEAVY RAIN & FLOODS that affected the Gisborne East Coast region (about 6700 landslides). The Uawa catchment Soil moisture levels were much lower than Ex-tropical cyclones Fehi and Gita caused experienced some of the highest rainfalls (205 normal at the start of 2018. Prolonged dry heavy rainfall and significant flooding for mm/12 hrs) which triggered multiple debris conditions prompted the Ministry of Primary parts of the South Island during February flows in areas of recent forestry, resulting in Industries to declare a medium scale adverse 2018. On 4-5 June, torrential rain caused significant amounts of wood being deposited event for Grey and Buller Districts, as well flooding and slips in the Tolaga Bay area (East on the beach at Tolaga Bay. We had projects as Otago and Southland in January. In 2018, Cape). Debris flows containing forestry slash that allowed us to map the landslides in the several Auckland locations recorded their damaged bridges and houses. driest spring on record. 54 NATURAL HAZARDS | 2018

10 YEARS NATURAL HAZARDS RESEARCH PLATFORM

IMPACT ADVICE ACTION ADVICE INTERNATIONAL

Researchers Volcanic hazards NIWA joins the Unified provide expert Christchurch City researchers provide Model Consortium – testimony to the Council uses NHRP advice to emergency links NZ research on Royal Commission research to identify managers on weather prediction & on the Canterbury Port Hills Red Zone eruption scenarios climate simulation with Earthquakes global partners

INTERNATIONAL ADVICE ACTION INTERNATIONAL

NZ Government NZ is signatory to the Tsunami Blue Lines provides additional Sendai Framework on introduced in NHRP provides $13.5M for psychosocial Disaster Risk Reduction; Wellington; later science advice to services based on the NHRP office provides used in Oregon and CERA CERA Wellbeing survey technical support to the Washington, USA results NZ delegation

SCIENCE • Canterbury EQ Recovery • Recovery research • Researchers develop National research informed by contributes to CERA Tsunami Hazard Model for all stakeholders – includes Wellbeing index & survey NZ coasts geological, geotechnical, engineering • Canterbury research • NIWA & Scion develop the develops Liquefaction National Fire Weather System Resistance Index map

HAZARD Nationwide storms, Ex-tropical including Canterbury wind storm Mt Tongariro White Island volcanic eruption volcanic unrest

2009

Nelson floods: Nelson-Tasman Christchurch flooding complicated ‘state of flood by subsidence from Canterbury emergency’ earthquake sequence Canterbury Cook Strait- earthquake Lake Grassmere sequence earthquakes 55

ACTION ACTION ADVICE INTERNATIONAL o- After Kaik ura, risk Kaiko-ura earthquake modeling influences NZ volcanology teams Engineering research landslide inventory amendment to the provide advice to contributes to Detailed completed; recognised Building Act to address international colleagues Seismic Assessment by overseas peers as following eruptions in risk from URM and shorten one of the best repair deadlines to EQP Guidelines Vanuatu & USA available globally buildings

ACTION ACTION ACTION ADVICE

Wigram-Magdala Bridge Resource Management Tsunami vertical is 1st NZ bridge to use Fire services utilises Act reforms pass into law, evacuation guidelines low-damage technologies; NIWA modeling during recognises management considered for NZ Christchurch’s Tu-ranga the Port Hills Fires of ‘significant risks from with advice from Library includes low natural hazards’ NHRP researchers damage design

• Researchers prepare report • Risk researchers & Bay of • Researchers contribute to • Following the Kaiko-ura EQ, on sea level rise for the Plenty Regional Council updates of engineering slow slip events are introduced Parliamentary Commissioner develop award-winning guidelines & standards for into earthquake forecasts for for the Environment framework for public wind load, structures, and the first time globally engagement about risk geotechnical • Alpine Fault research refines • Coastal hazard researchers the recurrence interval for • Kaiko-ura earthquake • Research begins on a National develop a free storm surge M8 earthquakes to approx. recovery research – includes Volcanic Hazard Model & coastal hazard tool for 300 years geological, geotechnical, end-users engineering & economics • Numerical weather prediction – highest national resolution • RiskScape + MERIT modeling at 1500m; limited cases of tools are joined to explore regional NWP at 100m resilience investment

Ex-tropical Ex-tropical cyclones Ex-tropical cyclones Debbie, Cook Fehi, Gita, Hola

Port Hills Fire Nelson fires

2015 2019

Edgecumbe flood

Kaiko-ura earthquake 56 NATURAL HAZARDS | 2018