Orals

The European continent is in the lucky situation of hosting three Regional Hydroclimate Projects (RHPs) sponsored by the Global Energy and Water Exchanges Project (GEWEX) of the World Climate Research Programme (WCRP). These projects, though at various stage of their implementation, have the same objectives of providing a multi-disciplinary understanding of the water cycle under a changing climate and evolving human water usages. These RHPs cover three relatively different climates of Europe with their specific water challenges:
• HyMex: The Mediterranean region with extreme rainfall events and long droughts.
• BalticEarth: The Baltic region with its evolving cold conditions and biogeochemical linkages.
• PannEx: A transition climate in which humans have shaped the water usage during the last centuries.
The budgets between the various processes of the water balance (precipitation distribution and intensity, evaporation characteristics or contribution of surface and ground transports) are very different within each region and thus impacts of climate change will also differ. Two of these regions furthermore include the coupling to a closed sea. Human water usages have over the centuries adapted to the physical characteristics of the water cycle within each regional climate and are thus very different in all three regions.

In order to help prepare our societies to a different climate and ensure adequate water resources, we need to advance our process understanding and enhance our forecasting capabilities at all scales from days to centuries. Thanks to these RHPs we can bring together the critical mass of scientists of various disciplines to illuminate the different aspects of the water cycle and our water resources in each region. Focusing on certain regions also allows developing specific solutions for each of the regions and communicate more directly our knowledge to decision makers and the public at large.

This session invites oral and poster presentations dealing with the main scientific questions identified in these European RHPs. Several of these questions are common to other part of Europe and the world. Thus, this session will focus on the specific scientific, observational, forecasting, impact, application, collaboration and socio-economic issues:

• Water balance at the basin scale;
• Forecasting extreme rainfall events and their evolution in a warmer climate;
• Forecasting of Basin floods and flash floods: water for societal security under changing climate conditions;
• Understanding drought formation and improving early warning systems;
• Impact of irrigation on the water cycle;
• Agro-climatological and biological systems: Agriculture response to climate changes and weather extremes;
• Local climate interactions with energy fluxes: agronomical process modelling and micrometeorology,;
• Urban issues: urban metabolism, energy flows and interactions with surrounding areas;
• Regional climate modelling: Extreme weather and climate events as a risk to sustainable development;
• Regional Earth System processes which couple physical, biological and chemical cycles of the atmosphere, land and ocean.
• Impact and vulnerability assessments of climate changes and extreme weather events on different socio-economic sectors;
• Outreach, exploitation and education.

The conveners will also organise a short panel discussion within the session to examine which coordinated actions could be undertaken between the three European RHPs.