RiskScape case study
In 2023, Cyclone Gabrielle caused loss of life and significant damage to buildings, infrastructure and primary production, particularly across Hawke’s Bay and Tairāwhiti.
The most significant impacts were those caused by flooding (including erosion and silt deposition) and landslide hazards. After the cyclone, RiskScape was used to underpin two ‘microsites’ for those responding to the disaster: a rapid impact assessment tool and a planning and recovery tool.
“This work accelerated RiskScape development as a multi-hazard risk modelling and information sharing platform. Together, these microsites helped organisations across Hawke’s Bay and Tairāwhiti to quickly work out what was exposed and impacted from Cyclone Gabrielle, and to make decisions about how to prioritise recovery efforts. It’s anticipated that the sites will also help other regions and areas with risk-based management of future hazards.”
Ryan Paulik, NIWA Hazard Analyst
This work was funded by the Ministry for Business, Innovation and Employment (MBIE)’s Extreme Weather Research Platform, set up after MBIE identified an urgent need to support government and non-government agencies in understanding impacts and developing an evidence base to support recovery in affected communities.
The rapid impact assessment tool provides a scenario model framework to rapidly assess natural hazard exposure or impacts. It was developed using publicly available exposure data for flood and landslide exposed elements such as buildings and roads, alongside public and private sector supplied hazard datasets such as river flooding, landslides and silt deposition. The tool was configured to report metrics on exposure to Cyclone Gabrielle hazards – for instance, number of schools, length of road and area of pastoral land affected.
The planning and recovery tool provides scenario and probabilistic model frameworks for risk assessment of cyclone-related hazards (i.e., river flooding, landslides) and other hazards (i.e., coastal flooding, earthquake shaking and liquefaction, tsunami) in areas affected by the cyclone. It quantifies risk metrics including reinstatement costs, people’s lives at risk and people displacement days from residential buildings. The microsite provides several features for adaptation planning including geospatial adaptation layers, comparing results, risk matrix and cost benefit analysis.
