Visualising flood risk: a view from the street

Communicating flood risk presents a significant challenge to flood managers. Members of the public often have difficulty relating to hydraulic model results and there is sometimes a degree of scepticism regarding their accuracy. To make flood information to the public and other stakeholders more accessible, an application has been developed to superimpose flood model outputs onto a photographic representation of the affected area. This can be viewed on site using a mobile device or on a desktop computer. The application enables the location of the user to be provided either by mobile device sensors or through map-based navigation. The user can then explore different flood water levels on request to represent “what if” scenarios and observed flood events. This approach enables stakeholders to see what a flood will mean for individual streets and properties, and will facilitate comparison of flood information from modelling with their own experiences. The presentation will describe the technique, and demonstrate a number of potential applications. For example, the impacts of climate change and flood alleviation schemes on floods of different magnitudes can be shown based on flood levels predicted by hydraulic models. The technique has been tested on the floodplains of the River Thames, where major flood schemes are planned that will use flood relief channels to lower flood levels. In this case the impact of the schemes on flood levels for different flood events can be clearly demonstrated