A Vehicle OverTurning (VOT) Model: How Can An Impact Based Model Be Verified?
This presentation will demonstrate ideas for how impact models can be verified, using the Vehicle OverTurning (VOT) Model as an example. This model has been developed as part of a Hazard Impact Model (HIM) under the auspices of the Natural Hazards Partnership, which is a collaboration between a number of UK agencies including the Cabinet Office. The aim of the HIM is to produce early warnings for severe events that allow us to generate an overall picture of the risk to society based on probability and impact. The VOT model uses uses the high resolution MOGREPS-UK ensemble to generate a probabilistic risk value for likely disruption to the road network based on wind gust speed and direction. This probabilistic hazard value is then combined with vulnerability and exposure values to give an overall risk value termed 'Risk of Disruption' which indicates the severity of road disruption due to a vehicle overturn.
During the winter 2013/2014 the UK experienced an exceptional number of high impact wind storms. These storms have provided a number of interesting case studies to use as verification for the VOT model, however finding data on actual vehicle overturning events to do this verification has proved laborious with inconsistent and limited results. Despite this, a number of data sources have been identified including news reports, social media reports, including twitter, police data and the Met Office Weather Observations Website (WOW, http://wow.metoffice.gov.uk/). Overall the VOT model appears to verify well using the currently collected data suggesting it provides useful guidance on the risk of disruption during high wind events. It is hoped that a more time-effective method of verification, allowing continual verification, will be developed in the near future using impact data from multiple sources.