The Southern Africa Flow Database, established between 1992 and 1997 to support rainfall-runoff modelling, contains flow time series data from about 815 stations across Southern Africa (SA). Initially hosted at the University of Dar es Salaam during the SA FRIEND Phase I and maintained by CEH in Wallingford in Phase II, the SA Flow Database is operated by GRDC since November 2010.

The Arctic-HYCOS forms the Arctic region component of the the World Hydrological Cycle Observing System (WHYCOS) implemented to support existing international initiatives. The objective of the Arctic-HYCOS Project is to allow the collection and sharing of hydrological data to evaulate freshwater fluxes to the Arctic Ocean and Seas, monitor the changes and enhance understanding of the hydrological regime of the Arctic region. GRDC hosts this dataset on behalf of the Arctic-HYCOS member countries.

The GEMStat Data Portal provides access to freshwater quality data and statistical vizualisations at different spatial scales. The data are voluntarily provided by countries and organizations worldwide within the framework of the GEMS/Water Programme of the United Nations Environment Programme (UNEP) .

The Global Runoff Data Centre is an International data centre operating under the auspices of the World Meteorological Organization (WMO). Its primary objective consists in supporting the water and climate related programmes and projects of the United Nations, its specialised agencies and the scientific research community by collecting and disseminating hydrological data across national borders in a long-term perspective.

Large-sample datasets are essential in hydrological science to support modelling studies and global assessments. This dataset is an extension to Caravan, a global community dataset of meteorological forcing data, catchment attributes, and discharge data for catchments around the world (Kratzert et al. 20231). The extension includes a subset of those hydrological discharge data and station-based watersheds from the Global Runoff Data Centre (GRDC), which are covered by an open data policy (Attribution 4.0 International; CC BY 4.0). In total, the dataset covers stations from 5357 catchments and 25 countries worldwide with a time series record from 1950 – 2022. GRDC is an international data centre operating under the auspices of the World Meteorological Organization (WMO) at the German Federal Institute of Hydrology (BfG). Established in 1988, it holds the most substantive collection of quality assured river discharge data worldwide. Primary providers of river discharge data and associated metadata are the National Hydrological and Hydro-Meteorological Services of WMO Member States. 1Kratzert, F., Nearing, G., Addor, N. et al. Caravan - A global community dataset for large-sample hydrology. Sci Data 10, 61 (2023). https://doi.org/10.1038/s41597-023-01975-w

The European Water Archive (EWA) collected long-term daily flow data and catchment information from more than 4000 river gauging stations in 30 countries. In October 2014 the EURO-FRIEND-Water meeting in Montpellier concluded that the EWA will no longer be updated and will be "frozen at its current state". By release and on behalf of the data providers, the former EWA stations and flow data will be integrated in the Global Runoff Database. The archived data remain unchanged and will be provided by GRDC on special request by writing to grdc@bafg.de. Please use the GRDC station catalogue on the GRDC Portal for up-to-date data of stations in Europe.

WMO Basins and Sub-Basins (WMOBB) is an ongoing GIS project of the Global Runoff Data Centre (GRDC). This dataset was created for the generation of GRDC map products and will be updated from time to time whenever extensions are required by future GRDC projects. At present the dataset comprises GIS layers of WMO Basins 2020 and WMO River Networks 2020.

Objective weather types of Deutscher Wetterdienst derived from different Reanalysis and Global Climate Model simulations for the control run (1951-2000) and the projection period (2000-2100). On the one hand, the dataset is useful for evaluation of representative circulation statistics in Central Europe, on the other hand, for the analysis of future weather types due to climate change. Added temperature and precipitation data allow to study the weather type effectiveness for these important climate parameters.

The Watershed Boundaries of all GRDC Stations are generated on the basis of HydroSHEDS (Lehner et al., 2008) and the Multi-Error-Removed Improved-Terrain (MERIT) Hydro dataset (Yamazaki et al., 2019). It is updated as soon as changes in the metadata occur or new stations have to be implemented. The dataset is licensed under CC-BY-4.0. Source: Lehner, B., Verdin, K., and Jarvis, A.: New Global Hydrography Derived From Spaceborne Elevation Data, EOS, 89, 93-94, https://doi.org/10.1029/2008EO100001, 2008. Yamazaki, D., Ikeshima, D., Sosa, J., Bates, P. D., Allen, G. H., and Pavelsky, T. M.: MERIT Hydro: A High-Resolution Global Hydrography Map Based on Latest Topography Dataset, Water Resources Research, 55, 5053-5073, https://doi.org/10.1029/2019WR024873, 2019.

The Annual Characteristics and Long-Term Statistics offer basic hydrological statistics of timeseries data of the gauging stations being represented in the Global Runoff Database. Annual characteristics are derived from monthly discharge data, either through aggregated daily data or originally provided monthly data. Long-term statistics and long-term variability are derived from annual characteristics too.