Water and Global Change (WATCH) was a €13M Integrated Project funded under the European Union’s Sixth Framework Programme. It ran from February 2007 to July 2011. It brought together the international hydrological, climate, and water resources research communities to resolve the water cycle at the global scale so that studies of climate and hydrology become inseparable in the future.
The foundation of WATCH was built on understanding the water cycle in the recent past. In doing so, researchers were able to assess the ability of hydrological models – often developed at local and regional scales - to receive data from climate models and produce results at a global scale.
Key to this was the development of a consistent set of climate data for use as input. The WATCH Forcing Data covers the period 1901 – 2001 and is based on a global 0.5 degree x 0.5 degree (~ 50km x 50km) grid. It comprises eight climate variables. The 21st century data set – the WATCH Driving Data – covers the period 2001 – 2100. It was created using a novel bias-correction methodology applied to three well-established climate models, each running for two IPCC future emissions scenarios.
Both data sets are freely available to the world’s research community, providing a significant new resource for future projects.
Using these data, WATCH completed an ambitious Water Model Inter-comparison Project. This led to the development of data and tools to provide a reliable multi-model approach to assessing impacts on the water cycle. The models were shown to be fit-for-purpose for estimating river flows at global, continental and regional scales. This has allowed the first steps to be taken towards a consistent assessment of water availability. This approach is similar to the one taken with climate studies – such as in IPCC Reports – and will reduce the need to rely on local hydrological studies that are unlikely to be representative at a global scale.
In looking at extremes, WATCH has compiled an exceptional pan-European set of observed river flow data from more than 400 stations. These data have contributed to the compiling of the Flood and Drought Atlases. These publications capture the characteristics of droughts and floods over the 20th century across Europe. They can be combined with other key data sets to produce figures for the human, economic and environmental consequences of individual historical events.