Windstorm Hazard and Risk Maps for the Netherlands in a Changing Climate

Extratropical cyclones (ETC) generate hazardous weather conditions, such as windstorms, which often result in substantial societal impacts. The Royal Netherlands Meteorological Institute (KNMI) has developed high-resolution wind climatology for the Netherlands using downscaled reanalysis data (2.5 × 2.5 km²) from 1979 to 2021, and they created ensembles for various climate scenarios based on IPCC projections. While these datasets offer valuable insights into windstorm hazards (e.g., maximum wind gust, maximum hourly wind speed), further evaluation of trends and probabilistic analysis are needed to create hazard maps tailored to specific return periods.

Our study addresses this research gap by exploring the application of extreme value theory (EVT) to windstorm hazard data to assess the likelihood of extreme wind speeds at specific locations. We analyse thresholds, seasonal variations, and storm frequency trends. Historical records and projections are analysed. A key novelty is the use of high-resolution post-disaster insurance claims data on the losses of windstorm. These data are used to create a risk model that converts windstorm hazards into quantifiable risks, such as expected annual damage and high-resolution risk maps (2.5 × 2.5 km2). This risk-based approach provides insights for stakeholders and decision-makers, aiding in the design of strategies to mitigate and adapt to windstorm impacts.