Sliding Lands Hōretireti Whenua
As a hilly country with high rainfall and frequent earthquakes, landslides are an ever-present hazard in many parts of the country, with climate change likely to increase the risk of landslide events.
To increase Aotearoa’s resilience against rapid and dangerous landslides triggered by extreme weather or earthquakes, we need to understand when and where such landslides may occur, what their impacts could be for a range of disaster scenarios, and how to effectively communicate the risk and impact to affected communities.
About the project
Hōretireti Whenua / Sliding Lands is a five-year research programme focused on enabling better decision-making through accessible landslide hazard and risk information.
At the heart of the programme is the development of a National Rapid Landslide Hazard Model (NRLHM), designed to forecast where rapid and dangerous landslides may be triggered by earthquakes or heavy rainfall. Alongside hazard modelling, the programme is assessing who and what may be affected by landslides, the likely consequences, and how this information can best support both short-term emergency response and long-term planning decisions.
To achieve these goals, the programme is structured around three interconnected research pillars:
- Social Science
- Landslide Hazards
- Landslide Impacts.
Social Science
The Social Science research pillar focuses on making sure landslide information is useful, understandable, and relevant for different users.
This research explores how people and organisations understand landslide hazards, how they make decisions using hazard and risk information, and what support they need. The findings will help develop practical guidance and communication tools that make complex scientific information easier to use.
Research activities include:
- Improving how landslide information is communicated.
- Supporting decision-making before, during, and after landslide events.
- Strengthening emergency management capability.
- Developing landslide education resources for Kura Kaupapa Māori.
- Learning from past events such as Cyclones Bola and Gabrielle to help build future resilience.
Landslides Hazards
The Landslide Hazards research pillar is developing a National Rapid Landslide Hazard Model that will help identify areas where fast-moving landslides are likely to occur during heavy rainfall or earthquakes.
The model will provide nationally consistent information about landslide hazards and help identify areas where people, homes, roads, and other assets may be at risk.
The model will support:
- Emergency response and recovery.
- Land-use planning and development decisions.
- Identifying areas that may need more detailed investigation.
- Long-term risk reduction and resilience planning.
The model uses information from past landslide events, rainfall records, earthquake data, LiDAR, remote sensing, and new advances in modelling and artificial intelligence.
More detailed studies will also be carried out in selected high-risk locations to improve and test the model.
Landslide Impacts pillar
The Landslide Impacts research pillar focuses on understanding the consequences of landslides for people, communities, buildings, businesses, and infrastructure.
Using information from hazard models and real-world case studies, researchers will assess the potential impacts of landslides on:
- Life safety and wellbeing.
- Homes and buildings.
- Roads and critical infrastructure.
- Communities and economies.
The research will help improve how landslide risk is measured and understood across New Zealand, supporting better planning and investment decisions.
The programme will use tools such as RiskScape(external link)xternal link) and the MERIT Tool(external link) to estimate the social and economic impacts of landslides and better understand how different communities may be affected.
The effectiveness of the landslide models will be tested and refined using two case studies based in Tairāwhiti and Auckland.
Project phases
- Develop nationwide probabilistic models for earthquake-induced and rainfall-induced landslides of varying landslide types and sizes.
- Research perceptions of landslide phenomena and associated vulnerability.
- Apply our novel impact-based landslide forecast models to case studies to test their effectiveness to real-world scenarios.
- Refine model outputs and communication frameworks that maximise the usability of model results for end users.
The models
The models will comprise:
- susceptibility
- runout
- vulnerability and risk.
The programme will create probabilistic models of landslide susceptibility using physics-based knowledge and machine learning techniques to develop rapid landslide nowcasts and forecasts. The programme will also develop a suite of landslide runout models for different landslide types, that will estimate how far debris travels downslope to determine what might be impacted.
The outputs of these models will be used to develop nowcasts and an impact-based warning system for landslides during earthquakes and when heavy rainfall is forecasted. The system will generate automatic impact-based warnings to support response and emergency management efforts by NEMA, local CDEMs and MetService.
The research will also investigate the behaviour and perceptions of individuals, communities, iwi, and organisations in response to landslides. The results from this research will be woven into the risk models by rethinking how we deal with vulnerability and use that understanding to inform effective hazard- and risk-based communication strategies, ultimately developing new vulnerability models for people, infrastructure, and buildings.
Data and tools
The models will be built on years of scientific research, a vast catalogue of landslide data - including an inventory of more than 140,000 Cyclone Gabrielle-induced landslides, availability of high-resolution rain radar, LiDAR and other remotely sensed datasets, advances in modelling techniques including using artificial intelligence and machine learning techniques, and information on people’s perception of landslide hazards, their associated vulnerability, and the model outputs.
The programme will use RiskScapeTM(external link), an open access, multi-hazard risk modelling tool, to create national-scale landslide forecast models by integrating hazard and vulnerability model components with the MERIT Tool to quantify the socio-economic impact of landslide hazards.
Case studies
The two case studies are designed to develop and test the models to ensure they are fit for purpose. They will also allow the programme to extensively progress and disseminate the new knowledge gained from this research via databases, models, geospatial datasets, forecasts and nowcasts.
Tairāwhiti
A case study in Tairāwhiti will focus on iwi and will recognise the distinctive research, science, and innovation contributions of Ngāti Porou. It will be led by and support Mātauranga Māori and Kaupapa Māori research by:
- detailing learnings from recent landslide events,
- co-designing a landslide response framework for hapū, iwi and the community, and
- enhancing natural hazard preparedness and response in Kura Kaupapa Māori/schools.
Auckland
A case study in Auckland will assesses the social and economic vulnerability and risk to people, businesses, and the local community from landslides, incorporating climate change scenarios. It will explore the impact of landslides using key socio-economic metrics that examine:
- the value of the data and model for key decision-makers, and
- whether improvements in model resolution and quality from the susceptibility, runout, and vulnerability and risk models result in better decision-making.
Funding and collaborators
This research programme is funded by $10.5 million from the MBIE 2023 Endeavour Fund.
The programme is led by Earth Sciences NZ, with research partners Massey University, Manaaki Whenua Landcare Research, Te Runanganui o Ngāti Porou, Market Economics, University of Auckland, Resilient Organisations, University of Canterbury, Durham University (UK), ETH Zurich (Switzerland), and Canary Innovation Ltd.
Earth Sciences NZ is working with partners and stakeholders from central and local government.
Programme leads and team
The Sliding Lands team of researchers bring a variety of academic fields with different expertise, from social science to computer simulations to field work.
Visit our people and connections page for full details of the programme team.
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