Eurowind™ - EQECAT's Europe Windstorm Model
Eurowind is a fully probabilistic risk model that quantifies prospective risk from windstorms in Europe and is part of RQE™ (Risk Quantification & Engineering), EQECAT's catastrophe modeling software platform. The Eurowind model has undergone several major updates since its initial release in 1997. Since 2003, the wind hazard model has been based on measured gust wind speed data. In 2008, the output from an Atmosphere Ocean General Circulation Model (AOGCM) analysis enabled the creation of a "hybrid hazard" model that integrates aspects of numerical and physical modeling into the model's empirical hazard foundations.
The follow images display sample Eurowind catastrophe modeling portfolio analysis:
Eurowind Catastrophe Modeling Methodology - Portfolio Analysis
Windstorm Risk Model for Europe
Windstorms are a class of extra-tropical cyclones that pose significant risk to insured assets across the European continent.
Recent historical events of note (and their estimated insured losses) include the following Europe windstorms:
- Daria and Vivian in 1990 - €3.98 billion and €1.64 billion respectively
- Lothar, Martin, and Anatol in 1999 - €4.61 billion, €1.95 billion, and €1.87 billion respectively
- Jeanette/Irina in 2002 - €1.33 billion
- Erwin in 2005 - €2.03 billion
- Kyrill in 2007 - €4.53 billion
- Klaus in 2009 - €2.34 billion
As evidenced recently in 2010 with windstorm Xynthia with a loss of €1.25 billion, damage may result from both high winds and resulting flooding from coastal storm surges.*
* Munich RE NatCatSERVICE, January 2010. Xynthia figure based on PERILS AG value, 12 April 2010.
Key aspects of the Eurowind risk model include the following features:
Broad Geographic Coverage
Eurowind covers 22 countries across Europe for wind damage:
||the Czech Republic
Correlated storm surge peril is modeled for:
- United Kingdom (UK)
Robust Wind Hazard Definition
Eurowind's hazard definition is based on measured wind speed data from up to approximately 3,900 European meteorological stations. Gust and sustained wind speeds and wind direction data was obtained via national meteorological agencies for the period 1960 to 2008. Data from the National Climatic Data Center and National Centers for Environmental Protection was used to maintain the homogeneity of hazard intensity, direction, and duration.
The empirical foundation of the hazard model allows for a realistic assessment of inter-country risk correlation for Europe. Eurowind's embedded wind modifier, representing local surface roughness, "gustiness", and topographical conditions, removes local effects and converts irregularly-spaced measured wind speeds to "free wind" speeds that are then smoothly interpolated. These conditions, on a 500-meter grid, are later reapplied to probabilistic free wind speed footprint events to determine a realistic wind hazard at any site location. Together with wind direction variations, these conditions are used to quantify wind speed uncertainty at each location.
Storm Surge Hazard
This is modeled for the UK, France, and Sweden. Wind speeds and wind directions extracted from individual footprints of the stochastic event set drive the storm surge hazard. Combining these with astronomical tide and mean sea level conditions generates sea heights for coastline locations. By using individual pan-European storm footprints, the correlation between sea sites is preserved.
Coastal defence information is embedded in the model, and defence failure is modeled probabilistically, generating inundation probabilities and flood propagation scenarios using a hydrodynamic approach.
Flood depth determines hazard intensity, with site elevation and building vulnerabilities determining damage.
Vulnerability functions are based on data from engineering studies, post-disaster reports, and expert studies.
Stochastic Event Set
The stochastic event set is based upon the stochastic perturbations of past events, and this is considered to be the most suitable approach for generating synthetic events of asymmetrical complex systems. EQECAT’s complete stochastic event set provides a rich representation of storms of all intensity, location / geographic breadth and duration to produce stable and reliable model outputs. Eurowind's stochastic event set is a hybrid, consisting of a mix of perturbations of historical events and AOGCM-modeled storms that resulted from a long-run AOGCM analysis (from 1860 to 2000 using the ECHAM5 model) in collaboration with the Free University of Berlin. EQECAT’s hybrid modeling approach enabled the refinement of important aspects of the event set, such as frequencies, clustering, and physical storm parameters, to reduce hazard model uncertainty while maintaining the distinctive character of extra-tropical storms in Europe.
Vulnerability functions were developed first using a "ground-up" approach with engineering studies, then refined with insurance claims data. An empirical understanding of the effects of a wide range of wind speeds for all relevant building types was combined with investigations into the relative vulnerabilities of different building codes across modeled countries. Engineering data sources included EQECAT's parent company, ABS Consulting. Forestry risk vulnerabilities are included for Sweden and Finland, based on tree types and heights.
Measured and modeled wind speed data (after transformation using the model's wind modifier) have been compared for key historical events for significant correlation. This was recently conducted for windstorm Xynthia with positive results. To verify that the generated stochastic event set fulfills these conditions, all major parameters of stochastic storm events were calculated and compared to those from the historical set.
Eurowind model specifications include:
Lines of Business
Structure Types and Occupancies
All major structure and occupancy types per line of business are modeled.
- Business Interruption
Exposure Import and Disaggregation
Data can be imported at latitude/longitude level, postcode, place name, CRESTA Zone, or country level. When input data is provided at aggregate levels, the model adds refinement to loss results by disaggregating data to finer resolutions points based on weighted distribution of values. For aggregate levels of exposure data, the model performs appropriate disaggregation for the purpose of analysis and risk estimation.
Hazard Analysis Resolution
Hazard analysis is on 500m x 500m grid, based on underlying digital terrain and land-use data.
Risk metrics include OEP and AEP loss exceedance curves, AAL, TVAR, and simulations of historical events.
Reporting of results supports multiple levels of refinement such as:
- Total aggregate portfolio
- Postal code
- Detailed output by policy and site
Different peril components (wind only, wind and flood) can be modeled to obtain model results accordingly. In addition, RQE’s Year Loss Table (YLT) uniquely features three-dimensional output: simulation year, events, and sample outcomes. Instead of reporting mean losses with standard deviations, each loss in the YLT represents one possible outcome for the associated event. This allows users to retain the full distribution of uncertainty when using model output in dynamic financial analysis and capital modeling.
Conventional event loss results and other risk metrics can be derived from the YLT with arithmetic or simple database queries. YLT and event loss results are supported at the portfolio level. Other risk metrics are supported at multiple levels of refinement: from total aggregate portfolio results, to detailed output by policy and site. The model is usable for risk differentiation, risk pricing, risk aggregation, and portfolio risk management, with suitable output and reports.
All major insurance policy structures and reinsurance treaty types are modeled.
Europe Windstorm Data Products
The insurance exposure data for Eurowind is available through EQECAT’s Insured Exposure Data (IED) for Eurowind. The Eurowind IED includes a breakdown of insured exposure values geographically, distributed by line of business and is formatted for analysis within Eurowind.
Request Eurowind windstorm wodel information from EQECAT.