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.

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

Watershed Boundaries of approx. 7500 GRDC Stations generated on the basis of the HydroSHEDS drainage network (Lehner et al., 2008). The "Watershed Boundaries of GRDC Stations" are provided in GeoJSON format.

The Global Terrestrial Network for River Discharge (GTN-R) is the river discharge component of the Global Terrestrial Network - Hydrology (GTN-H) to support the Global Climate Observing System (GCOS) and the Hydrology and Water Resources Programme of the WMO (HWRP). The basic idea of the GTN-R project is to draw together the already available discharge data provided by the National Hydrological Services (NHS) and to redistribute it in a standardised way. Core component is the GCOS Baseline River Network of gauging stations located near the mouth of the world's major rivers. In cooperation with the Hydrological Services of the WMO Member States this network is continually being extended by confirmation of additional stations.GRDC contributes to the GTN-H by collection of discharge data. Access to GTN-R data follows GRDC's data policy of free and unrestricted but identified access and is limited to noncommercial applications. Use the GCOS/GTN-R stations catalogue to create your individual list of project stations for download via GRDC Data Portal.

The GRDC "Major River Basins of the World" is a web application provided by the Global Runoff Data Centre (GRDC) to present the "Major River Basins of the World" data product. The "Major River Basins" and "Major River Networks" layers represent 520 river/lake basins considered “major” in basin size, or in their hydro-political importance or interest. 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 the GIS layers of GRDC Major River Basins 2020, GRDC Major River Networks 2020 and GRDC Major Rivers 2007.

BALTEX (the Baltic Sea Experiment) was launched in 1992 as a Continental-scale Experiment (CSE) of the Global Energy and Water Exchanges Project (GEWEX) within the World Climate Research Program (WCRP). The research focus of BALTEX was primarily on the hydrological cycle and the exchange of energy between the atmosphere and the surface of the Earth. The study region of BALTEX is the Baltic Sea and its huge catchment region. In 2015, the BALTEX Hydrological Dataset moved from Swedish Meteorological and Hydrological Institute (SMHI) to the GRDC in order to ensure sustainable operation and regular updates as an integral part of the Global Runoff Database. By release and on behalf of the National Hydrological Services, the former BALTEX stations and flow data are integrated in the Global Runoff Database.

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.

The GRDC Freshwater Fluxes into the World’s Oceans is a web application provided by the Global Runoff Data Centre (GRDC) to present the Freshwater Fluxes into the World’s Oceans data product. Continental freshwater input into the oceans is computed by the GRDC at irregular intervals, most recently in December 2020 referencing the time period 1901–2016. Previous data sets prepared in 2004, 2009 and 2014 are integrated into the service.

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 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.