Impact case study:
Models and tools for decision making

 


September 2021

A key part of our mission to accelerate natural hazard resilience is development of new models and tools to quantify natural hazards and their associated social and economic impacts in more detail, allowing for better assessments of resilience options. 

As highlighted in our 2019-20 reporting, our Earthquake & Tsunami team have successfully developed a prototype of their ground-breaking synthetic earthquake catalogue.

The team starts with a 3D model of Aotearoa New Zealand and its faults, then uses computer calculations to simulate forces that cause earthquakes. When the forces acting on a fault overcome its strength, this triggers a ‘synthetic’ earthquake. Researchers can then see how the synthetic earthquake redistributes stress onto nearby faults and leads to subsequent earthquakes.

As well as feeding into analysis and advice during the March 5 tsunami response (see Impact Case Study: Responsive Science for National Emergencies), the catalogue has been used in numerous other applications. For example, the team used an M8.5 Hikurangi subduction zone earthquake from the synthetic catalogue to test the ability of an instrumented submarine telecommunications cable running from Napier to Chatham Islands to deliver tsunami early warnings for large Hikurangi earthquakes. This work was done in collaboration with a working group of the Joint Task Force on Smart Cable Systems. Bill Fry has provided advice to MBIE and EQC on the impacts of the proposed cable.

Pillar One of our Coastal programme involves creating a national coastal-change database to record a sequence of detailed snapshots of Aotearoa New Zealand’s entire 15,000 km coastline. The objective is to identify how fast our coastline is changing, and which areas are most prone to erosion. The work is complete for Northland and the database is being used to inform coastal spatial planning in the region.

While analysing Southland’s coastline, the University of Auckland’s Dr Murray Ford and his team identified a rapid rate of change adjacent to the Tiwai Pt aluminium smelter toxic waste storage facility. Dr Ford told RNZ: “Over the last decade or so the behaviour of that beach has changed. We’ve seen 30 to 40 metres of erosion since about the year 2010.” The sea is now just 75m from the concrete pad storing 180,000 tonnes of waste laced with cyanide and toxic fluoride.

In the course of this research, Murray and his team have been able to raise awareness of a previously unknown and urgent problem.

Credit: Graham Hancox, GNS Science

In December 2019, the Wellington Lifelines Group delivered their Regional Resilience Project report, identifying 25 key infrastructure projects needed to boost resilience in the region over the next two decades, at a cost of $5.3b. The report relied heavily on economic modelling using MERIT (Measuring the Economics of Resilient Infrastructure Tool), a tool developed under Phase 1 of the Resilience Challenge and a key part of our Phase 2 Multihazard Risk programme.

The Wellington Regional Resilience Project was Highly Commended in the Collaboration category of 2021 Emergency Management Awards. Judges recognised ‘a true collaboration of Central Government, Local Government and all of the Wellington Lifelines Group members with private enterprise to deliver what has been recognised as a world-leading approach to infrastructure resilience analysis.’

The MERIT team has also been recognised in the 2021 Lloyd’s Science of Risk Prize. The team placed second in the Pandemics category for their work on ‘Accounting for business adaptations in economic disruption models’.

The capacity for businesses to adapt in the face of adversity has been demonstrated through the Covid-19 pandemic, and the inadequacy of economic modelling tools to account for this adaptation is shown in economic losses and business closures significantly lower than predicted. The team’s research is the first of its kind to build an empirically-derived model of business impact and recovery following disruption. The research has important implications for the insurance sector, because for insurers to maximise their capacity to support organisations through crises, risk models need to account better for the capacity of businesses to adapt. 

MERIT analysis was also central to a technical report prepared by our Multihazard Risk team for Hawke’s Bay Regional Council, assessing water demand under climate change. The work uses the Dynamic Economic Model (a component of MERIT), various greenhouse gas trajectory scenarios, and independently developed water accounts to project water demand for the region. The work represents the first attempt undertaken in Aotearoa to assess future water requirements under climate change.

 

This case study was submitted to the Ministry of Business, Innovation and Employment as part of our 2020-21 annual reporting. 

 

Impact case study:
Responsive science for national emergencies

 


September 2021

Once again, 2020-21 provided numerous opportunities for our researchers to provide high quality analysis, advice and public commentary as natural hazard events unfolded, and in the aftermath.

On the morning of September 18th, winds picked up in Auckland and an extreme gust measured at over 120km/hr blew two trucks sideways on the Harbour Bridge, seriously damaging the bridge structure. Several lanes were closed for weeks while repairs took place, leading to lengthy traffic delays and flow-on economic impacts.

Research carried out by NIWA as part of our Weather & Wildfire programme combined a computer model of wind patterns in the harbour with a three-dimensional model of the bridge and found the bridge itself causes the wind to speed up.

“The effects here are very localised and it is really important to understand these better because of the risk high wind events have to a range of assets such as transport and distribution networks and the potential knock-on to economic impacts,” said our Weather & Wildfire programme co-leader Dr Richard Turner in a media story. The research has demonstrated a potential tool that could be a component of a warning system that could halt traffic on the aging bridge and prevent a repeat incident. 

March 5 sequence. Credit: GNS Science

On the morning of March 5th, a M7.2 earthquake struck off the East Coast of the North Island, and an M7.4 and M8.1 followed soon after in the Kermadecs. The quakes triggered a tsunami alert for large parts of Aotearoa New Zealand. Our Earthquake & Tsunami programme co-leader Dr Bill Fry (GNS Science) provided science advice to the National Crisis Management Centre and explained the situation at the press conference fronted by Minister Allan.

The Earthquake & Tsunami team’s synthetic seismicity catalogue had previously been used to test the Tsunami Early Warning (TEW) system being developed under the aligned ‘Rapid Characterisation of Earthquakes and Tsunami’ Endeavour programme, also led by Bill Fry. On March 5th, Bill and other team members used a prototype of the TEW system to inform decision making during the response. Testing using the RNC synthetic catalogue gave the team confidence that the prototype TEW system was appropriate to base scientific advice on. This led to a much quicker input of advice supporting tsunami warning cancellation.

The NEMA post-event report recognised Fry’s contribution, stating: “There was recognised value in having a GNS Science representative (Fry) contributing to the media stand-ups to provide scientific context and advice, and to support the preparation of the Minister for Emergency Management and Acting Director CDEM.” The timing of the March 5 events also created significant interest in our scheduled webinar on the synthetic earthquake catalogue the following week.

Autumn 2021 saw record-breaking drought in parts of the country after an exceptionally dry 2020. Dr Nick Cradock-Henry of Manaaki Whenua Landcare Research, co-leader of our Resilience in Practice programme, has worked extensively with rural communities, agri-business groups and local and central government on natural hazard responses and resilience solutions. Focusing on climate change and drought, Nick’s research in North Canterbury and Marlborough has highlighted the need for applied resilience solutions, including improved monitoring and evaluation, climate services and targeted support. Both in the media, and in a well-attended webinar as part of our rolling symposium on drought (see Impact Case Study: Partnership as the Pathway to Impact), Nick provided informed commentary on the ways that drought can exacerbate existing social and economic vulnerabilities, and evidence-led solutions for drought-affected communities. 

On 28 May MetService issued a red alert for the Canterbury region forecasting 200-300 millimeters which they warned could cause significant flooding. An extreme rainfall event followed, causing extensive, damaging flooding in the South Canterbury area, and resulting in the declaration of a region-wide state of emergency from 30 May to 10 June.

Our researchers provided expert commentary on the floods. In particular, Asaad Shamseldin of The University of Auckland and our Built Environment team provided useful expertise on ‘atmospheric rivers’, how this phenomenon contributed to the devastating impacts in South Canterbury, and the increased frequency of atmospheric river events in a changing climate.

 

Damage from May 2021 flooding. Credit: Timaru District Council

There has also been public discussion on the description of such events as ‘a 1 in 100 year flood’ or similar, given underlying climate conditions are changing so rapidly. Prof Ilan Noy of Te Herenga Waka Victoria University of Wellington and our Multihazard Risk team, was on the ground in Westport during the devastating floods in July and critiqued this terminology and the false impression it creates regarding likely recurrence.

 

This case study was submitted to the Ministry of Business, Innovation and Employment as part of our 2020-21 annual reporting. 

 

AF8 Roadshow 2021: The Science Beneath Our Feet

 


August 2021

 

We can’t predict earthquakes, but we can prepare for them. The AF8 Roadshow: The Science Beneath Our Feet shares Alpine Fault hazard science and preparedness information with communities likely to be impacted by the next Alpine Fault earthquake. It is designed to enable conversations, activate local knowledge, and support informed decision-making to increase awareness of, and our preparedness for, a future event.

New Zealanders are excellent at coming together to support each other in an emergency. The AF8 Roadshow encourages people to have these conversations in advance, so we can be better prepared for a future Alpine Fault earthquake.

Building on the success of the 2019 AF8 Roadshow, the 2021 itinerary was expanded to 16 public science talks and 16 school visits around the South Island. This second tour was well-received with record turnouts and an increased demand for information, reaching a total of 2,974 people over the course of 8 weeks from March-July 2021. The full 2021 itinerary can be found here.

 

Full house in Kokatahi. Credit: AF8

The AF8 Roadshow leverages the close partnership between science and emergency management, demonstrating the value of working together to be better prepared for natural hazard events in New Zealand. The talks are hosted by the local Emergency Management Group, with 11 science presenters of diverse expertise supporting the delivery of the public science talks in 2021.

AF8 Programme Lead, Alice Lake-Hammond explains, “By making this science available in a community setting, sharing it in a local context where it is of most relevance to the community, this is where it comes alive and where we see actions beginning to be taken.”

Mt Hutt College, Methven

“An hour-long talk is typically followed by an hour-plus Q&A session where the audience can gain clarification of the hazard science and better understand how it applies to them.”

“Often the answers start to come from within the community itself and it this sharing of local knowledge and experience that is so crucial to moving from a general awareness of the hazard to an active preparedness for a future event.”

The South Island Emergency Management Groups also recognise the AF8 Roadshow as one of the most effective way to bring their communities together to connect:

“This is a fantastic opportunity for our communities to be involved in learning more about an event that could impact on them. The Roadshow really makes science accessible.” – Emergency Management Officer, Marlborough.

And, the engagement and feedback from schools has been equally as positive:

“The 3D mapping demonstrated the content really well. Students were able to visualise content that had been previously discussed. The tutor was inclusive and made sure everyone could see and have input into the discussions.” – Teacher, Otago

“I’m really scared of earthquakes. But now I understand why we have they and what I can do about them, I feel much better. Thank you for coming.” – Student, Golden Bay

The more we talk about the Alpine Fault, the more people want to know and it’s important that we keep these conversations going. A third AF8 Roadshow is planned for 2022.

 

AF8 Roadshow partners include: the six South Island Emergency Management Groups, The Earthquake Commission, QuakeCoRE: NZ Centre for Earthquake, Resilience to Nature’s Challenges and GNS Science.

 

Student Profile: Thomas Wallace

Understanding the Physical and Systemic Vulnerabilities in Integrated Stopbank-Dam Catchments


June 2021

I grew up in sunny Nelson, New Zealand where I enjoyed many opportunities to connect with nature through tramping, mountain biking and family holidays in the Marlborough Sounds. In my final year of high school (after causing a lot of stress for Mum) I decided to pursue engineering. During my undergrad, I found a passion for water. Water is essential for life and connects us to the natural environment.

Following my undergrad, my friend connected me with my primary supervisor who took me on for a Masters project, ‘Determining the flood effects of undocumented stopbanks within the Waimea floodplain’. This project helped me to find myself, my passion for research, and a desire to improve the lives of individuals and communities. After my Masters, I sought to continue with research where I am now working toward my PhD at the University of Canterbury investigating vulnerabilities in flood management. My supervisors are Kaley Crawford-Flett, Tom Logan, and Matthew Wilson, and my PhD research is supported by the Resilience Challenge through the Built Environments programme.

During my free time, I enjoy trail running, rogaining (orienteering), alpine skate touring, and reading (in particular Terry Pratchett).

My project

My research is looking at the management of stopbank-dam catchments during floods.

The aim is to help move the management of these structures away from an individual element approach towards a broader system perspective. In particular, focus is being given to deepening the understanding of their operational and physical vulnerabilities. This will contribute to building New Zealand’s flood resilience to flood disasters.

The phases of research will be focused on:

  • Developing the understanding of maturity in operational elements in our flood defence systems so that risk-reducing activities may be more effectively prioritised
  • Using operational vulnerabilities to undertake probabilistic breach flood modelling to determine the exposure of communities and infrastructure to flooding
  • Developing alternative operational strategies and high-level recommendations that are able to reduce the exposure of communities and infrastructure

My research aims to raise the awareness of vulnerabilities in these systems and highlight their potential effects while providing recommendations to address these. This is hoped to shift the management of these catchments towards a more systematic view where the importance of each dam and stopbank, and the connections between them, is acknowledged. A more systematic approach to catchment management will improve resilience and reduce risk in our flood exposed communities. Because although some flooding is normal, we don’t want it to be a dam problem!

 

 

Next steps

The next steps for me are to complete my research proposal and begin developing the maturity matrices used to assess the maturity of the operational elements in our flood defence systems. After this, I’ll be undertaking a series of interviews with stakeholders for data collection.

 

 

Student Profile: Yi-Wun Mika Liao

Developing physics-based modelling of synthetic earthquakes to access and forecast fault rupture, ground shaking, tsunami and landslides


June 2021

I was born and raised with two siblings by my grandparents in Taiwan. I graduated from the Department of Earth Science of National Central University, Taiwan, and studied ground motion simulation of historical earthquakes during my master’s years. After I got my master’s degree, I worked as a research assistant for several years. I’ve been thinking whether to get a PhD or not for many years. Therefore I recommended myself when one of my current supervisors, Dr Bill Fry, visited Taiwan and said he was calling for PhD students. The topic of the PhD project and the beauty of New Zealand are both so attractive to me, so I decided to join the project after talking to my supervisor.

I am a fluffy animal lover, especially dogs and cats. I like to hike although I don’t have many chances to hike in Taiwan because there are too many frogs and snakes in the mountains. Due to the Covid-19 pandemic, I am still waiting for the border restriction to be lifted. I am keen to go to New Zealand and hike in the frog-and-snake free mountains!

 

My project

Determining the input parameters for hazard assessment, such as recurrence interval of earthquakes for a given magnitude, rupture initiation on the fault, and probability of multiple-segment rupture, is quite difficult, especially for large earthquakes due to the short time period of our earthquake records. Physics-based earthquake simulators are one solution to this problem. Since our goal is to increase resilience to earthquakes, it is important to understand the possible recurrence interval of these events from a simulated catalogue of earthquakes, spanning more than 50,000 years. The aim of my project is to develop the modelling of synthetic earthquakes and generate simulated earthquake catalogues with a physics-based earthquake simulator, RSQSim.

New Zealand and Taiwan are both located at subduction zones and have high seismicity. Seismic hazard assessment is mandatory for both countries. Since I am still in Taiwan and more familiar with Taiwanese data, I am first trying to simulate the synthetic earthquakes with the seismogenic structures of Taiwan. By trying different values of the input parameters of RSQSim, such as initial stress, and comparing the results with the observed earthquake catalogue, I have learned what types of input values lead to the most realistic results. However, the simulated earthquake catalogues still couldn’t fit the observed one perfectly. There are some ways to improve the simulated catalogues, like adding more seismogenic structures and constraining more of the input parameters of RSQSim. This part would be more challenging.

 

Next steps

One of the next steps is to apply what I have learned from the Taiwanese data to New Zealand. As mentioned above, the improvement of seismogenic structures and constraint on the input parameters could be also one of the next steps. I hope that some realistic earthquake catalogues could be generated, and that this will help to assess the likely frequency of earthquakes and their related hazards.

 

Modelling the social and economic impacts of a volcanic eruption in Auckland

 


By Robert Cardwell

June 2021

A research team led by University of Auckland PhD candidate and Market Economics researcher Robert Cardwell recently published new research on the simulation of economic and urban development recovery pathways following the eruption of a new volcano in the Auckland region.

The research, published in the Journal of Volcanology and Geothermal Research, demonstrates the capability to simulate not only the direct physical impacts associated with infrastructure and land use destruction and disruption, but also population and business evacuation and relocation. The team also modelled the socio-economic and land use planning implications associated with recovery and also the longer-term growth-related pressures on city development.

Figure 1 shows the impact on value added (the counterpart to Gross National Product at the regional level) of the volcanic eruption scenario over a 20 year period following the eruption compared to a baseline scenario where the eruption did not occur.

 

Figure 1: Eruption and Baseline integrated scenario total value added for industrial and commercial sectors

Figure 2 depicts the difference in development of residential and industrial land use that has occurred by September 2040 in the volcanic eruption scenario compared to the baseline scenario under a ‘Fast Recovery’ scenario.

 

Figure 2: Change in residential and industrial land use between 1st October 2019 and 30th September 2040 in the ‘Fast Recovery’ scenario

Figure 3 depicts the difference between two scenarios at September 2040 where in one scenario the land physically impacted has been remediated within a timeframe of 5 years, and another in which the remediation has taken 10 years.

 

Figure 3: Land use in ‘Fast Recovery’ scenario as at 30th September 2040 vs ‘Slow Recovery’ scenario as at 30th September 2040

The differences between the ‘Fast Recovery’ and ‘Slow Recovery’ scenarios demonstrate how taking longer to remediate the area directly impacted by the volcanic eruption can result in more urban development on the urban-rural boundaries than might have otherwise occurred.

As far as the authors are aware, this research is the first instance of simulation of land use and economic changes over time after a natural hazard event has occurred. The developments demonstrated in this research will enable planning authorities to assess trade-offs with competing objectives in mitigation and redevelopment strategies to respond to volcanic eruptions and other natural hazard events.

The research was co-authored by Robert’s supervisors Assoc Prof Liam Wotherspoon (University of Auckland) and Dr Garry McDonald (Market Economics), with support from Prof Jan Lindsay (also University of Auckland). Funding was provided by the Resilience Challenge Economics and Urban research programmes with support from DEVORA (Determining Volcanic Risk in Auckland).

 

Q & A with Dr Shari Gallop

 


Q. Tēnā koe Shari. Can you tell us a bit about your iwi and hapū connections?

I whakapapa to Ngāti Maru (Hauraki) through my dad and Te Rarawa in Northland through my mum. I also have Danish and English ancestry. Since I moved back to Aotearoa New Zealand in 2018 I have connected with my iwi and it has been really awesome learning about where I come from, and figuring out my place in the world and as a Māori scientist. It has been really rewarding sharing this journey with my supportive husband and our kids have been part of it too, and it makes me feel good knowing they won’t have to search like I did.

Shari on waka hourua Te Matau a Māui as part of a Te Ahu o Rehua wānanga in March 2021.

Q. How did you get into coastal science? Were you always fascinated by the sea?

I grew up in Kawerau and Manawahe in the Bay of Plenty, and had a very outdoorsy childhood. I was always drawn to water – rivers, lakes, and the ocean. As a child some of my best memories are at the beach with my grandparents and having whānau-days at Lake Rotoma.  At school I got into science and really enjoyed it so I started a science degree at the University of Waikato. I really enjoyed marine science then surprised myself by enjoying it so much that I wanted to carry on studying with a Masters degree and later a PhD. It wasn’t a career path I thought I would take!

Q. What did you focus on for your PhD research?

I was lucky to do my PhD in Perth at the University of Western Australian with Professor Charitha Pattiaratchi. I focused on how coastal reefs affect beach stability, erosion and recovery at a range of scales, including storm events through to decades. Many coastal engineering structures attempt to mimic the coastal protection that can be offered by natural features such as reefs. One of the interesting things we found was that sometimes reefs can actually increase beach erosion, rather than reducing it, such as when they constrain current jets between the shoreline and the reef that can quickly move sand eroded from the beach along the shore.

Q. Congratulations on your recent appointment to co-leader of the Resilience Challenge Coastal programme. You’re also very involved in the programme’s Coastal Flooding project. Could you briefly summarise the objectives of the programme for us?

Shari getting ready to deploy an Acoustic Doppler Current Profiler during PhD field work in Perth.

Thank you! I am grateful for this opportunity to step up into this leadership role and work with our amazing team. In the Coastal programme we are looking to solve coastal hazard questions that communities around Aotearoa New Zealand are facing. We have three main projects (pillars): Pillar One focuses on developing a national framework to consistently assess the changes to the coastline around Aotearoa New Zealand which will help make better predictions for the future. Pillar Two is about improving our understanding of coastal flooding, including developing better ways to predict flooding in our estuaries and accounting for human actions, and how to predict risk when you have many different coastal hazards coming together. Pillar Three is around coastal adaptation, including developing new tools to assist decision-making that accounts for uncertainties, and is sustainable.

Q. You’re based at the University of Waikato’s Tauranga campus, focused on researching coastal dynamics, hazards and estuaries. Why is understanding estuaries so critical in building resilience to climate change?

Estuaries are relatively shallow bodies of water found where rivers meets the sea, and occur on coasts all around the world. There are more than 300 in Aotearoa New Zealand including around our major cities such as Auckland and Christchurch. They are hugely important for many reasons, including because they provide unique ecosystems that provide us with resources such as food. In terms of our climate, estuaries and their wetlands are hugely important for capturing carbon from the atmosphere (‘blue carbon’) particularly mangroves, saltmarsh and seagrass that are found in estuaries. Estuaries also play an important role in aquaculture industry to feed our expanding population.

Q. In 2020 you were awarded the L’Oréal-UNESCO Women in Science fellowship for New Zealand. What does this recognition mean to you?

This fellowship was a great opportunity to share my research with a wide audience, and enable a conversation about climate change; particularly about the importance of our coastal and marine environments and how we all have responsibility to take care of it. Personally, it has also been an exciting journey working with L’Oréal and building my networks and capability in science communication.

Credit: L’Oreal

Q. What are your aspirations as an emerging Māori researcher in the coastal science space?

It is a really exciting time to be learning how to work in this space, I think we are currently in a big shift in bridging western science with Te Ao Māori (Māori world view). My training has been largely as a western scientist and I am really enjoying connecting to my whakapapa, and being in spaces where I can grow in my mātauranga Māori. I am newly on the steering committee of Te Ahu o Rehua: A Network for Cross Cultural Ocean Knowledge and have found this network invaluable to learn how to be Māori in science, and also a space to contribute to helping smooth the path for students and build my capacity to support the next generation of scientists.

 

Q&A with Akuhata Bailey-Winiata

Mapping coastal marae and urupā


April 2021

 

Akuhata onboard the waka houora Te Mātau a Māui in Napier, 2021

Tēnā koe Akuhata. Can you tell us about your iwi affiliations?

Yes, my iwi affiliations are Ngāti Whakaue, Tūhourangi, Ngāti Tutetawha, and Nāti Tawhaki.

What motivated you to pursue your current research on climate threats to coastal marae and urupā?

At the end of 2019 I graduated with my Bachelor of Science in Earth Science with a minor in Geography at the University of Waikato. Then I started a summer scholarship at our Tauranga campus funded through the Resilience Challenge and supervised by Prof Karin Bryan, Dr Shari Gallop and Dr Scott Stephens (NIWA). We used GIS (geographic information system) to map the proximity of marae to the coast and rivers and started looking at their elevation, distance to the coast and slope. I realised the impact that this research could have for my people and my country. From there I was hooked, and I got the opportunity to start my masters which has brought me to where I am now.

Could you briefly summarise the objectives of your research?

The overall objective is to understand the exposure of coastal marae and urupā to a rise in sea level. We will achieve this by first understanding the characteristics of these coastal marae and urupā such as elevation and distance to the coast. As well as using NIWA coastal flood maps to categorise which coastal marae or urupā may be inundated at increments of sea level rise. Following this, we focus on classifying the coastal geomorphology of these coastal marae and urupā which will be critical to understand how the coast will respond to a rise in sea level. Lastly we want to start exploring what is the way forward and what is next to address this issue in the best way for Māori.

What have you found so far?

191 marae around Aotearoa New Zealand are within 1 km of the coast and 41 Bay of Plenty urupā are known to be within 1 km of the coast. Of these 191 coastal marae, 30% are situated below 10 m above sea level. Of the 41 coastal urupā we looked at, 40% are situated below 10 m above mean sea level. We have also conducted a geomorphic analysis of coastal marae and urupā because different types of coasts will have very different responses and management requirements. We found that the most common type of coast around marae is shallow drowned valleys (such as Tauranga harbour) with 38% of coastal marae having this geomorphology. Followed by coastal embayments (such as hot water beach) with 21% of coastal marae having this geomorphology.

 

Field sampling in the little Waihī estuary

What aspects of your research have been most challenging?

The most challenging aspect of this research is engagement. This is because marae and urupā are such important historical and cultural sites to Māori and anything that threatens their safety is an emotive issue.

What do you hope will come out of your research that will have real world impact for iwi and hapū?

The outputs from this research will be the first baseline investigation which seeks to understand the exposure of coastal marae and urupā to a rise in sea level. I hope that this data can be used in the future by coastal marae, hapū and iwi to make informed and relevant decisions to help protect and preserve these sites of significance for future generations.

What specific mitigation strategies can you foresee that will help safeguard affected marae and urupā?

This is the hardest question that I am faced with when talking with coastal communities, so what? What do we do? And when do we do it? Potential solutions to safeguard marae and urupā from coastal flooding and erosion can be complex and expensive, and dependent on the coastal environment of these coastal marae and urupā. Hence creating a solution is going to need to incorporate these factors and more.

 

Atop a cliff looking down at a shoreplatform at Rēkohu (Chatham Islands), 2019


What are your future research aspirations?

I am planning to continue my research with a PhD, looking at the potential solutions for coastal marae, urupā and communities to combat sea level rise and potentially how to provide relevant and digestible information to make it easier to make informed, collective decisions to protect and preserve coastal marae and urupā.

 

 

Student Profile: Ben Jones

Investigating coastal archaeological vulnerability in Aotearoa

 


April 2021

 

Tēna koutou katoa

Ko Crocodile te awa

E hono ana ahau ki Royal Oak Tāmaki Makaurau

Ko Ben Jones tōku ingoa

He Kairangahau ahau ki te Whare Wānanga o Tāmaki Makaurau

He mihi nui, he mihi aroha!

 

I was born in South Africa in a small rural community. At the age of 15 I came to Aotearoa and made Auckland home. As an immigrant you attempt to learn everything you can, every bit of slang, idiosyncrasy and the finer points of ‘yeah nah, nah yeah’.

I formed a connection with Aotearoa through its history. Undertaking my undergraduate and Masters research at the University of Auckland enabled me to dig deeper into Aotearoa’s past. Stumbling into archaeology unpacked the scope and complexity of the human past, especially the coastal heritage of Pacific Islands. For my Masters I investigated how rice agriculturists impacted an intensive pre-contact agricultural system in Hawai’i. I was hired as a GIS technician job based on the techniques I developed using applications of GIS and LiDAR during my Masters. My role in the project was to digitise and service online all the maps produced by the Crown. (over 20,000 maps, 5000 of them geo-referenced). Cataloguing the cartographic history of Aotearoa yielded a knowledge base useful for my PhD research and wider public use.

For the past 5 and a half years I have been working as a professional archaeologist in Aotearoa and in Australia. The takeaway from this role for me was the engagement with iwi and hapū who have an ancestral connection to the archaeology I have investigated. The best encapsulation of this is the proverb ‘Kia whakatōmuri te haere whakamua: ‘I walk backwards into the future with my eyes fixed on my past’. Iwi, hapū and local communities are faced with potentially losing these places due to sea level rise driven by climate change.

 

My project

My PhD project stems from the Coastal research programme within the Resilience to Nature’s Challenges (RNC) National Science Challenge | Kia manawaroa – Ngā Ākina o Te Ao Tūroa. Thanks to my great supervisory team Mark Dickson, Emma Ryan, Murray Ford and Dan Hikuroa. The overall aim of the RNC Coastal programme is to resolve physical coastal hazard questions faced by communities around Aotearoa. Incremental sea-level rise (SLR) and changing wave patterns will fundamentally reshape our coastlines and re-define Aotearoa’s future coastal hazards. One of the coastal assets at risk is cultural heritage, particularly archaeological sites related to Māori occupation. Many of these sites are located close to coastlines and are vulnerable to coastal hazards exacerbated by SLR. Factors of particular significance include large tidal ranges and storm surges especially in shallow harbours, river mouths and estuaries. Coastal erosion is a key threat to the preservation of archaeological sites, either exposing sites to future destruction and/or destroying exposed sites. 37.3% of archaeological sites recorded are within 500m of the coast. Further research to investigate the vulnerability of coastal archaeological sites is needed, in order to understand what that percentage means at different national, regional and local geographic scales. Understanding the impact and the scale of the problem is important, both from a scientific and cultural perspective, because these sites hold evidence of Aotearoa’s tangible and intangible history.

 

Figure 1: What coastal archaeology in Aotearoa is at risk?

Figure 2: LiDAR of Ngunguru sourced from Northland Regional Council. The barrier contains numerous significant archaeological sites related to Māori settlement.

My PhD focuses on understanding coastal change at selected sites within Aotearoa over the past 1000 years and considering how future SLR will impact coastal archaeological sites. An interdisciplinary study where a three-pronged approach will adopt techniques from the disciplines of Mātauranga Māori, archaeology, and geomorphology. Successfully achieving this provides a range of exciting prospects. For example, what the distribution of archaeology means for understanding coastal change, what archaeology is at risk from SLR and how pūrakau (myths) link to the broader understanding of coastal change. The challenge, then, is to meaningfully design a research programme that incorporates the methods of Mātauranga Māori, archaeology and coastal geomorphology.

 

Next steps

I hope my research will have two impacts. The first is nuanced and sensitive collaboration with the iwi and hapū related to my case study area Ngunguru, in Northland. I have started engagement with Te Waiariki and aim to refine the research by examining and re-examining the research with their input from the start.

My second aim is to increase awareness of the threat posed to archaeological sites and that it will inform effective adaptive climate change policy. I have been invited to and actively involved in a working group with the mission task to provide a national level of guidance and advocacy to address the effects of climate change facing Aotearoa’s cultural heritage. Hopefully, by engaging with policy makers and government officials during the early stages of my PhD it will enable effective communication of the threats posed to archaeological sites.

 

Improving volcanic ballistic projectile hazard assessments using UAVs and a pneumatic cannon

 


By Dr Rebecca Fitzgerald

April 2021

 

Volcanic ballistic projectiles (VBPs) are fragments of solid rock or molten lava ejected out of a volcano in explosive eruptions. They are one of the most common causes of deaths and injuries on volcanoes, as they can travel up to hundreds of metres a second, range up to tens of metres in diameter and land with very high temperatures (up to 1000°C). VBPs can also cause substantial damage and destruction of property and infrastructure. Despite this, VBP hazard, impact and risk research has trailed behind other volcanic hazards.

This means that hazard and risk managers are missing out on crucial information that would help them calculate risk to people on volcanoes.

We understand how VBPs travel, how far they travel, and their size, but little is understood of 1) how they are distributed within a ballistic field (are there more impacting in certain areas than other areas?); 2) the intensity of VBP hazard within the field (are there a lot impacting a small area, making it hard to escape being hit, or are there only a few impacting a large area?); and 3) how their distribution around the volcano changes over time (will they always impact the same area? Will a similar number be ejected in each eruption?). These questions affect the decisions hazard and risk managers make to keep people safe.

In addition, we know that an impact by a VBP can cause injury or death, yet this is not the only aspect that may cause injury. Impact ejecta are often produced when a VBP impacts the ground, either from interaction with debris (i.e. gravel, scoria) on the surface or from the VBP shattering. The ejecta can also increase the size of the area of hazard around a VBP and may have the ability to injure (Figure 1).

 

Figure 1: VBP hazard footprint size is influenced by many factors. In this example we can see how impact ejecta is produced from a less dense VBP impacting a hard surface, increasing the hazard footprint (in birds eye view on the right) compared to a denser VBP impacting the same surface and not fragmenting on impact (P= person, B= volcanic ballistic projectile, EA= ejecta apron).

It is critical for hazard and risk managers to know the potential size of the hazard footprint that a person could be affected by and the number of VBP that may be experienced in an area to calculate risk effectively. This became the topic of my PhD thesis at the University of Canterbury.

To investigate how the number and density of VBP impacts change over a VBP field, we used a drone to take images of the area and map the location of VBPs at Yasur Volcano, Vanuatu.

 

Figure 2: A map of Yasur volcano with craters outlined and locations of the trails, viewing locations and the car park. Either side of the map are two examples of 20 x 20 m squares used to map VBPs in different distances and directions on the volcano. A and C show the drone images pre mapping and B and D show the same images with all the VBP mapped in red dots. We can observe less VBPs in C/D at 500 m from the vent than at 300m from the vent in A/B.

Mapping revealed that the spatial density of VBPs, or number of VBPs in an area, varied across short distances, and decreased with distance from the crater (Figure 2). More VBPs were also observed on the south and south-east of the volcano than in other directions, indicating that eruptions were being preferentially directed in that direction.

The mapping results and video footage of eruptions taken while we conducted fieldwork suggests that eruption directionality changes over time, highlighting how dynamic the hazard is and the need for potential changes in eruption directionality to be considered in risk management decisions.

 

Figure 3: Pneumatic cannon at UC. A) Set-up. B) Frames from a video filmed at 1000fps of an experiment using a basalt block fired at 60m/s impacting basalt boulders and producing impact ejecta.

Pneumatic (compressed air) cannon experiments were used to investigate how impact ejecta can affect the hazard footprint from a single VBP (Figure 3). The amount of energy they travel with and how far they travel may change depending on the hardness of the surface the VBP impacts, the hardness of the VBP itself and how fast the VBP was travelling on impact with the ground. Therefore our testing included these factors. Findings showed that ejecta have the potential to cause injury or death but that this varied with the factors tested. This indicates a need to incorporate impact ejecta into hazard footprints as well as the VBP itself when calculating hazard intensity, vulnerability and risk to people from VBPs on volcanoes

Improving our current understanding of how VBPs are distributed in space and time, and how hazard intensity varies over the hazard footprint will vastly improve our ability to assess and manage VBP hazard and risk.