Transforming coastal lowland systems threatened by sea-level rise into prosperous communities
Aotearoa New Zealand’s coastal lowlands are our flat low-lying land (or plains) adjacent to coasts and estuaries. Our coastal lowlands are valued for many reasons, including unique ecological wetlands, cultural sites of significance, valued recreational areas, highly-productive agriculture and are popular places to live.
Unstoppable sea-level rise (SLR) will force changes to coastal lowlands and our use of these environments.
Future Coasts Aotearoa from NIWA on Vimeo.
Future challenges include:
- Rising groundwater levels
- Increasing frequency of coastal flooding and permanent inundation
- Salinisation (salt-intrusion to fresh groundwater)
- Loss of productive farmlands
- Coastal squeeze, which is the loss of intertidal habitat “squeezed” between rising seas and inland barriers
- Loss of ecologically unique and culturally significant wetland ecosystems.
Communities who depend on these coastal lowlands face considerable barriers to successfully transforming in the face of relative sea-level rise. Transformation requires developing the right tools to achieve “whole-of- system” adaptation across social and cultural well-beings, economic systems and natural environments. Successful transformation is achieved by supporting iwi/hapū/whānau aspirations as we balance protection and existing land-use rights with efforts to preserve and enhance ecological habitats.
Future Coast Aotearoa addresses this challenge by investigating how we can successfully transform coastal lowlands in terms of what to do, why to do it, where and when to do it?
Our overarching science challenge for Future Coast Aotearoa is to:
- Enhance the evidence base for sea-level rise risks (exposure, consequences, evolving environmental states, adaptation thresholds, positive/negative feedbacks)
- Build fit-for-purpose, multi-well-being evaluation tools, and
- Fold them into a dynamic adaptive planning and decision-making framework that transparently compares adaptation preferences in terms of costs, benefits, risks and opportunities across connected social, cultural, economic and natural systems.
Partnering with mana whenua
Integral to this research project is working with coastal marae, hapū and whanau to support their research aspirations and needs in the face of a changing climate.
One such partnership is with Te Puuaha whaanau (lower Waikato River) who are thinking long-term about the opportunities to work with nature and climate change to enhance environmental, social and economic outcomes. The partnership will build a climate resilience framework for their community and help build Māori worldview into the multi-well-being evaluations and associated decision-making processes.
We are finalising plans for a Kaituna River case study collaboration with the Te Maru o Kaituna who are seeking to restore, protect and enhance the environmental, cultural and spiritual health of the Kaituna River. We will engage with mana whenua in our other proposed case study site as these are decided.
Research programme
The research is shared across three interacting aims:
Definition: Relative SLR is the combination of global SLR with local land elevation changes like uplift or subsidence.
Research Aim 1: Exposure
Advanced understanding of the physical impacts of sea-level rise
Part 1: Freshwater-saltwater interface led by - Rogier Westerhoff (GNS)
Part 2: Wetland and intertidal evolution led by - Andrew Swales (NIWA)
Goals:
- Build a national database and interactive web-based maps of coastal wetlands, land-use and asset exposure in coastal lowlands with relative SLR.
- Produce a high-resolution, time-evolving, online mapping tool of Aotearoa-NZ’s freshwater-saltwater interface.
- Globally significant science advances will be required to understand ecosystem response and habitat evolution, and to identify adaption tipping-points and opportunities for wetland preservation or re-establishment.
Research Aim 2: Consequences
Build fit-for-purpose, multi-wellbeing evaluation tools
Led by Paula Blackett & Paula Holland (NIWA)
Goals:
- Accounting for sea-level rise consequences across all four well-beings will require big improvements to current evaluation tools. Our programme will be among the world’s first to capture cascading well-being impacts through time, using a dynamic economic model that includes non-monetary values and Māori worldviews.
- While some studies have evaluated the spatial-temporal distribution of physical sea-level rise impacts, we will stretch this to integrate social-cultural values within a spatial risk tool, so that non-monetary values can also be included in plan-making processes at regional and district spatial levels.
Research Aim 3: Adaption
Supply transformative tools to support decision-making and change
Led by Connon Andrews
Goals:
- We will use Serious Games to discover people’s behaviours and preferences for sea-level rise adaptation. We will use the Serious Game data to build a behavioural model that shows how people would behave over time in a changing climate in response to a range of policies and resource constraints.
- Designing policies to tackle real-world socio-economic challenges over many decades is difficult, due to a limited opportunity to experiment and test options. We will develop a virtual policy environment to “see the future”, allowing people to understand and evaluate the implications of different policy settings.
- We will identify appropriate methods for managed realignment, including how to manage coastal restoration and associated land-use planning matters, how to reconstruct coastal wetlands, and when to maintain or ramp-up provision of ecosystem services.
- We will bring together all the developed tools to develop pathway case study demonstrations for decision-makers.
Our research partners
Partner |
Role |
NIWA |
Overall programme lead Social sciences of communities facing coastal adaptation Economic analysis over four well beings Estuarine sedimentary processes and wetland evolution Blue carbon sequestration Coastal adaptation options Multi-hazard geospatial risk modelling via Riskscape |
NZ groundwater table modelling Coastal adaptation policy/planning |
|
Economics modelling with environmental and social dimensions |
|
Groundwater interactions and coastal aquifers. PhD student supervision |
|
Wetland evolution research Mana whenua partner for Lower Waikato River (Te Puuaha whanau) |
|
Wetland evolution measurement and modelling. PhD student supervision |
|
Modelling climate evolution of coastal wetland systems |
|
Groundwater salinisation and adaptation thresholds |
|
Systems mapping of interconnected processes to underpin economic modelling |
|
Conservation and restoration of coastal wetlands Wetland evolution modelling |
|
Multivariate economic modelling and options analysis |
|
Bell Adapt |
Coastal hazards, adaptative management and decision-making |
Decision-making under deep uncertainty |
Science journal publications
- Groundwater Rise and Associated Flooding in Coastal Settlements Due To Sea-Level Rise
- Coastal realignment, another coastal challenge
- Saltwater intrusion from an estuarine river: A field investigation
Related information:
- Understanding the threat of sea level rise to NZ’s wetlands
- Climate change experts tour New Zealand’s coastal wetlands
- Bay of Plenty iwi puts in place climate change strategy for Maketū (RNZ News)
- First devices installed in Te Moana a Toi to monitor estuaries (Newshub)