Hazard Impact Modelling

We are creating a series of Hazard Impact Models (HIMs). These are designed to produce impact and risk information for individual natural hazards. Most Hazard Impact Models are composed of three main elements: Hazard, Vulnerability and Exposure.

In order to ensure that all Hazard Impact Models conform to a level of standardisation, we developing a Hazard Impact Framework.

Stage 1 uses input datasets to describe potential hazards. This may be rainfall forecast data or data on natural processes such as soil conditions, ambient temperatures etc.

Stage 2 uses thresholds from current science to define when the potential hazard is significant enough to cause an impact. These thresholds may include measurements such as rainfall volume, wind speed, maximum temperatures, size of area affected etc.

Stage 3 of the model considers impacts that might arise from receptor interaction with the hazard. Input receptor data may include the locations and attributes of population and property data as well as transport and other infrastructure networks or different types of land use.

The locations of the receptors are used to calculate exposure. The attributes of the receptors are used to calculate vulnerability.


Hazard Impact Models may process multiple scenarios. For example, the Surface Water Flooding Hazard Impact Model uses Met Office Global and Regional Ensemble Prediction System (MOGREPS) data as an input, which currently uses 24 different rainfall scenarios. This produces a range of results, which are combined to form risk scores (usually at county level).

Hazard Impact Models in Development

Snow and Ice
Surface Water Flooding