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 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.

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.

The GEMStat Dashboard visualizes the water quality of global water bodies on different spatial and temporal scales, based on data from the GEMStat Database . Available data includes the parameters dissolved oxygen, nitrogen, phosphorus and pH, all core parameters of the UN SDG 6.3.2 water quality indicator. 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) .

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 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 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 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.

National Hydrological Services have identified “climate sensitive” stations on request of the WMO Commission for Hydrology in order to assess the variability and trends in hydrological data associated with climate variability and change. GRDC has offered to integrate this dataset into the Global Runoff Database.

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.