RiskScape case study
RiskScape has been used to assess climate-related coastal flood risk in the Pacific. The tool provides critical information to allow six Pacific nations – Cook Islands, Republic of Marshall Islands, Samoa, Tonga, Tuvalu and Vanuatu – to identify what’s most at risk and make crucial adaptation decisions.
This work is part of the Pacific Risk Tool for Resilience project, Phase 2 (PARTneR-2), funded by the Ministry of Foreign Affairs and Trade and jointly implemented between NIWA and the Pacific Community (SPC). The project aims to help countries in the Pacific become more resilient to the impacts of climate-related hazards.
“RiskScape enabled us to empower people across six Pacific nations to combine national-scale flood modelling with large exposure datasets to model climate-related risk into the future. Using this powerful tool meant we could customise outputs to support decision-making needs across many different stakeholders and contexts.”
Juli Ungaro, NIWA Climate Services Scientist & PARTneR-2 Project Manager
Through this project, researchers developed climate-induced sea-level inundation risk profiles for populations, buildings, croplands and critical infrastructure (including utilities/lifelines), under present and future climate scenarios at a national scale for each country.
The outputs are being tailored to support each country's unique needs, including:
- climate adaptation investment proposals
- infrastructure planning through identification of critical at-risk areas and timing of rising sea levels
- climate proofing through adapted building designs or staged relocation/services development planning (land use planning)
- sector-based needs such as risk to schools and health facilities.
The team carried out national-scale coastal flood inundation modelling taking into account digital elevation models, storm-tides and wave-processes, alongside sea-level rise increments up to 2 metres.
Above images: Projected water level in a 1 in 100-year water level event in Efate, Vanuatu (left) and Rarotonga, Cook Islands (right).
RiskScape was used to combine flood inundation maps with population and asset maps to estimate the risk of exposure and impact from flood inundation over the next 100-years. Risk information reported from RiskScape included the exposure quantity (i.e., count, square kilometres, type exposed) and direct tangible damage (i.e. $USD) represented as an average annualised loss. Results are available in the form of Excel files, Shapefiles, visualisation dashboards and ArcGIS Storymaps.
The impact of climate change into the future was assessed by factoring in expected changes in population, buildings, crops and infrastructure exposure and losses using country-specific sea level rise projections for five future shared socio-economic pathways (SSPs) from the most recent IPCC reporting.
Example of changes in Average Annual Loss over time for the various IPCC Shared Socioeconomic Pathways.
