This service includes a network of long-term (30 years) instrumented small hydrological catchments located in the South-Eastern Pyrenees (1100-1700 m a.s.l.) with a mean annual precipitation around 880 mm.

The scientific infrastructure and the available datasets in the Vallcebre research catchments consist of:

• A network of rainfall gauges to measure and sample rainfall. Precipitation is recorded (3 locations) at 5-min intervals and sampled for water stable isotopes (1 location) each 5-mm of rainfall and weekly (2 locations). Rainfall data are available for the period 1994 to 2020. Rainfall isotopic data are available from 2013 to 2020.
• Two complete meteorological stations, which record air temperature and relative humidity, net radiation and wind speed and direction at 5-min intervals. Meteorological data are available for the period 1994 to 2020.
• A network of gauging stations at the outlets of catchments ranging from 0.025 to 4.17 km². These gauging stations record stream discharge (5 locations) and suspended sediment concentrations (3 locations) at 5-min intervals. Stream water is also sampled weekly and during runoff events for water stable isotopes since 2013. Discharge and suspended sediment concentration data are available for the period 1994 to 2020. Stream water isotopic data are available from 2013 to 2020.
• A network of sensors for soil water content recording at 5-min intervals in the first 90 cm of the soil (3 locations). Soil water content data are available for the period 1996 to 2020.
• A network of piezometers for groundwater level recording at 10-min intervals (20 locations). Groundwater is also sampled weekly for stable isotopes since 2013. Groundwater level data are available for the period 2006 to 2020. Groundwater isotopic data are available from 2013 to 2020.

Two forest plots (Pinus sylvestris and Quercus pubescens) for eco-hydrological processes studies. These plots record throughfall, stemflow, soil water content and trees transpiration at 5-min intervals. Ecohydrological data are available along recurrent 2-3-year periods from 1995 to 2020. Throughfall, stemflow, soil water and xylem water have also been sampled for water stable isotopes along recurrent 2-3-year periods within these forest plots from 2015 to 2020.