Surface Water Flooding

The Surface Water Flooding component of our Hazard Impact Model project is led by the Centre of Ecology and Hydrology in collaboration with the Health and Safety Laboratory, Environment Agency, Met Office and the Flood Forecasting Centre. This model conforms to the Hazard Impact Framework guidance, which was largely influenced during development of the surface water flooding model.

The Surface Water Flooding component forecasts hazard, impact and risk information based on Met Office predictions of likely rainfall. These forecasts are used by hydrometeorologists at the Flood Forecasting Centre to improve their understanding of flood risk and potential impact, and to support their issuing of guidance through the Flood Guidance Statement to emergency responders.

The Hazard

The flooding hazard is based on the Centre of Ecology & Hydrology's Grid-to-Grid model, which converts probabilistic rainfall forecasts - based on the high-resolution Met Office Global and Regional Ensemble Prediction System (MOGREPS-UK) - into surface water runoff.


Impacts and Vulnerability

Impacts were grouped into four categories. Vulnerability was assigned by the function of a building and by a person's age and health. 

The impact data are combined with the Environment Agency’s Flood Map for Surface Water dataset to create a pre-calculated Impact Library of potential flood impact information. This is matched to probabilistic Grid-to-Grid surface runoff forecasts to produce scenario maps of flood impact severity. These maps are combined to produce county-level risk scores using the Flood Forecasting Centre's Flood Risk Matrix that links potential impact and likelihood to give an overall assessment of flood risk severity.


The Surface Water Flooding Hazard Impact Model is currently in a trial phase at the Flood Forecasting Centre, where it is being applied alongside existing tools to assist in the provision of flood guidance.

Conference Papers

Cole, Steven J.; Moore, Robert J.; Wells, Steven C.; Mattingley, Paul S.. 2016 Real-time forecasts of flood hazard and impact: some UK experiences [in special issue: 3rd European Conference on Flood Risk Management (FLOODrisk 2016)] E3S Web of Conferences, 7, 18015. 11, pp. 10.1051/e3sconf/20160718015

Aldridge, Timothy; Gunawan, Oliver; Moore, Robert J.; Cole, Steven J.; Price, David. 2016 A surface water flooding impact library for flood risk assessment [in special issue: 3rd European Conference on Flood Risk Management (FLOODrisk 2016)] E3S Web of Conferences, 7, 18006. 10, pp. 10.1051/e3sconf/20160718006