RAINGAIN

Climate change and rapid urbanisation will result in increasing water management problems in urban areas throughout this century. Urban areas in North-Western Europe are especially vulnerable due their high population densities and high concentration of industrial and infrastructural assets. The most important challenge is to obtain reliable data and predictions on rainfall events at urban scale, which are currently unavailable.

The RainGain project seeks to obtain detailed rainfall data at an urban scale, to use these data to analyse and predict urban flooding and to implement the use of rainfall and flood data in urban water management practice to make cities more resilient to local rainfall-induced floods.

Weather radars are the only measuring devices that provide estimates of rainfall in time and space. In the RainGain project, four different types of radar techniques have been tested in four pilot cities: Leuven, London, Paris and Rotterdam.

The fine-scale rainfall data provides urban water managers with detailed peak rainfall information at temporal and spatial scales appropriate to the fastness of urban run-off processes. The information has been applied in flood prediction models at pilot sites to identify flood-prone locations and develop effective solutions for better flood protection (such as early warning systems and optimised, real-time storage basin operation). These were tested based on the detailed rainfall data and flood models. The end users of the rainfall equipment, data and models were trained so they were able to take over the project deliverables and to resume responsibility in operation and management.

The aim of RainGain is to obtain detailed rainfall and flooding information in cities to improve resilience of urban populations and critical infrastructure. Different types of radars are installed and in 4 cities (Leuven, London, Paris, Rotterdam) for this purpose and different types of flood models are implemented. Through transnational cooperation local authorities learn about the pros and cons of different approaches in achieving urban flood protection. In 2013, a Local Authorities meeting was organised by the local partners in RainGain where a variety of city representatives from inside and outside the project shared and discussed experiences with radars and flood protection. Radars are operational in Leuven and London and new, state-of-the-art radars are under construction in Paris and Rotterdam. A review document on rainfall estimation was prepared in a shared effort by the RainGain partners, with additional contributions from external experts. Flood models have been set up in all 4 cities and a direct, transnational comparison between the models was made. RainGain partners summarised the results in a joint paper that was presented at a key international conference in 2014. Results are also disseminated to non-technical stakeholders through the National Observer Groups, RainGain website and educational platform. All the project results can be consulted in the following link: http://www.raingain.eu/en/project-results