The state forest of La Reine is a humid forest of about 5000 ha located in the south of the plain of Woëvre and at the foot of the Meuse hills in France. Numerous ponds and puddles are scattered throughout the forest and it is crossed by many small, more or less natural streams. Upstream of the forest, these waterways are impacted by human activities (large-scale farming, housing without collective sanitation in particular). Since 2019, the Moselle Basin Workshop Zone has been working on the implementation of a workshop site to understand the bio-hydrogeological functioning of three of these streams, particularly in terms of natural purification. Sampling campaigns are regularly organized in the streams and in ponds.

The observatory consists of 16 headstreams (15 in the Moselle River watershed, 1 in the Rhône River watershed), draining forest (mixed coniferous, beech) watersheds on sandstone and granites at very different altitudes.

The Galabre site is part of Draix-Bleone observatory, located in the French South Alps, upstream of Digne, on the right side of the Bleone river. The hydrosedimentary station of La Robine-sur-Galabre was created in 2008 to measure water of sediment fluxes from the Galabre catchment, 20 km2. This catchment integrates a diversity of lithologies and land use that are characteristic of the Pre-Alps. The climate is mountainous and Mediterranean. The site is characterized by intense erosion and intermittent sediment fluxes. The variables that are monitored on the long-term include rainfall and meteorology, high-frequency water discharge and suspended sediment concentration (10 minutes), some physico-chemical properties of stream water and sediments.

The Strengbach Watershed is a granitic watershed (80ha) located in NE of France, in the Vosges Mountains at altitudes between 880 and 1150 m (omsl) and with highly incised side slopes (mean 15°). This catchment is situated in a remote area lacking human activities except forest management. The forest covers 90% of the area and corresponds about to 80% spruce (mainly Piceas Abies L.) and 20% beech (Fagus Sylvatica). The climate is temperate oceanic mountainous. The site is manage by Ecole et Observatoire des Sciences de la Terres (University of Strasbourg / CNRS-INSU-France).

Aquitain's karsts observatory (Aquitaine, France) regroups different karst sites located on the edge of the Aquitain sedimentary basin. These karst watersheds range from 0.01 km² (Lascaux cave) and 1 km² (Cussac cave) up to 100 km² (Toulon springs) and the land use consists of forests and agriculture under modified oceanic climate. This observatory consists of various observation and experimentation sites like patrimonial caves and large karstic hydrosystem outlets.

Measurements of lake chemistry are part of lake monitoring, which is usually carried out by monthly sampling at many regular lake sites (5 to 17 sites depending on the intensity of the measurements over the years). The integrated sample represents the whole water column of this polymictic shallow lake with a mean lake depth of 1.2m. The measurement satisfy the analytical standards of Ö-Norm in Austria.

Plynlimon is at the headwaters of the Rivers Severn and Wye. The infrastructure at Plynlimon consists of 10 instrumented research catchments representing different land use options on the same geological parent material. It is the UK’s Critical Zone Observatory, part of the EU and global network of CZOs and is an ExpeER site. The infrastructure records high temporal resolution river flow and meteorological data (40 year data record) and stream water and precipitation chemistry for cations, anions, trace metals, nutrients, pH and alkalinity (30 year data record) and some data for suspended sediment. The site has an extensive spatial data library including topography, digital terrain model (DTM), soils, geology and vegetation/land-use available, open access, through the Environmental Information Data Centre (https://catalogue.ceh.ac.uk/documents/91961a0f-3158-4d00-984d-91eb1e03e8bd). Sub sites in the catchments represent a range of upland management types: mature/clear cut/replanted conifer forest; acid grassland; eroding peatland; improved grassland.Samples analysed for a wide range of major, minor and trace components. Bulk precipitation and cloudwater chemistry is also measured at one location.

The LTSER Zone Atelier Bassin de la Moselle belongs to LTER-France network and is located in eastern France, Lorraine / Moselle. The ZAM acquires knowledge for better controls the impact of human activities on the quality of the water resources in Lorraine County (France), in the watershed of the Moselle River.

The Baget catchment is managed by the Laboratory of Functional Ecology and Environment (EcoLab), a joint Research Unit between the Institute of Ecology and Environment (INEE) of CNRS, the National Polytechnic Institute of Toulouse and the University Toulouse III-Paul Sabatier, in collaboration with BRGM (Occitania regional agency), the laboratory Geosciences and Environment Toulouse (GET) and the Station of Theoretical and Experimental Ecology (SETE) in Moulis (Ariège, France). The Baget catchment (Pyrénées, Ariège, France) is a mountain ecosystem of middle altitude (Alt.= 1000 m) receiving around 1000mm of precipitation per year. Located close to Balagué village at 10 km West from Saint-Girons, the Baget catchment (13.25 km2) is drained by a karstic network which supplied the surface runoff of Lachein stream (specific discharge: 36 l.s-1.km-2). It is a tributary of the Lez which joins the Salat River, right tributary of the Garonne River. From 1968, this experimental site was intensively equipped by the CNRS underground Laboratory of Moulis (today SETE). The device is composed of one main weir at the outlet, 3 full excess controls, 3 piezometers of which one inside the abyss, and one subterranean loss. This karstic watershed has been surveyed since 1968 for some hydro-climatic parameters, particularly air temperature, precipitations and stream discharge at the outlet. Some geochemical parameters (pCO2, chemical and isotopic compositions of waters) and some hydro-biological and ecological data (invertebrates, particularly Crustacea) have been surveyed for periods during the last 40 years by the CNRS underground Laboratory of Moulis. Since 2011, Baget catchment belongs to the French Network of Catchments (RBV) and it is included in the certified National Observatory Service SNO Karst. Then, new parameters are measured twice a month or with higher frequencies during some flood events (major cations and anions, alkalinity, pH, conductivity, dissolved organic carbon, total suspended matter, H, O, C isotopes…). Since 2014, a multi-parameter probe has been installed with different sensors to measure continuously water level, pH, conductivity, turbidity, dissolved oxygen, nitrate and chloride. These continuous measurements are calibrated twice a month with laboratory analyses. The water discharge is measured by BRGM-Occitania because the Baget karst is part of the French patrimonial network of ground-waters and it belongs to the piezometric network managed by BRGM. The Baget catchment is very sensitive to limit conditions of surface drainage and to land covers. It offers the possibility to develop an eco-systemic survey, which integrates the hydrology, the geochemistry and the ecology of a mountain ecosystem in the SW of France. In this region, climate and land use changes will have significant impacts on biodiversity, ecosystem functioning and biogeochemical cycles for the next decades The Baget catchment is an international field site of the Critical Zone Exploration Network CZEN (http://www.czen.org/content/aurade-experimental-catchment) and it is one of the sites of the French SNO-KARST (Service National d'Observation) labellised by INSU-CNRS. It belongs to the French Research Infrastructure OZCAR and it is also a site of the French LTSER ZA PYGAR "Zone Atelier Pyrénées-Garonne".

Draix-Bleone observatory was created in 1983 to study mountain erosion and sediment transport. It is located in the French South Alps, upstream of Digne, on the left side (Draix site) and right side (Galabre site) of the Bleone river. Several catchments are equipped to measure water and sediment fluxes, at spatial scales ranging from 0.001 km2 to 34 km2, with contrasted land use and land cover. The smallest catchments are entirely situated on black marl that are very sensitive to weathering and erosion, resulting in a badland topography. The Bouinenc and Galabre catchments integrate a larger diversity of lithologies and land use that are characteristic of the Pre-Alps. The climate is mountainous and Mediterranean. These sites are characterized by their intense erosion and intermittent sediment fluxes. The variables that are monitored on the long-term include rainfall and meteorology, high-frequency water discharge and suspended sediment concentration (1-10 minutes), event-scale bedload transport, some physico-chemical properties of stream water and sediments. Draix-Bleone Observatory is managed by IGE and is funded by INRAE, INSU and OSUG. It is a member of the French research infrastructure OZCAR. The GIS Draix-Bleone gathers all research teams involved on these sites.