Water cycle and water resources of the Pyrenees under climate change: the PIRAGUA datasets.

The Pyrenees range is a transboundary mountain region shared by Spain, France and Andorra. As many other mountain regions, the Pyrenees host the upper catchments and recharge zones of the region's main river basins and aquifers. Therefore, it is the main source of water resources that are used in a much larger area that includes important urban concentrations and highly productive rural areas. This territory and its water resources are particularly vulnerable to the consequences of climate change. The PIRAGUA project (2018-2021, https://www.opcc-ctp.org/piragua), funded by FEDER through the POCTEFA Program of the EU, addressed the characterization of the hydrological cycle of the Pyrenees in a climate change context, in order to improve the territories’ adaptation capacity. The goals of the project were to unify and homogenize the existing information, prospect future scenarios, develop indicators of change, and propose adaptation strategies with impact on the territory. The project results were compiled in a series of regional datasets, and are available through the geo-portal of the Pyrenees Climate Change Observatory (https://opcc-ctp.org/geoportal). These include the following resources: PIRAGUA_resources stores information related to water resources use, exploitation and management; PIRAGUA_indicators contains daily streamflow and aquifer level indicators from observed series during the historical period (1950-2019); PIRAGUA_flood includes the number and classification of flood events, at the municipal level; PIRAGUA_atmos_analysis contains observation-based meteorological data suited for hydrological simulation, for the historical period (1981-2010); PIRAGUA_atmos_climate is a  statistical downscaling of six global climatic models, for the historical and future periods (1981-2100); finally, two datasets include the hydrological water cycle components derived from simulations with different hydrological models (SWAT, SASER, GIS-BALAN and RECHARGE) and climate forcings: PIRAGUA_hydro_analysis (1981-2010) and PIRAGUA_hydro_climate (1981-2100). This contribution is devoted to describing these datasets and the tools to explore them and acquire the data, and to provide examples of the main results regarding the climate change effects on the Pyrenees’ water resources.