Countries and organisations voluntarily provide water quality data from their own monitoring networks.
Data supply to the GEMS/Water Data Centre is voluntary. Data suppliers are requested to use the following Excel templates, where possible, to report stations and measured values.
Following a quality and consistency check, the supplied data are included in the GEMStat database.Excel-File
Data submission form for water quality monitoring dataExcel-File
To identify the measuring methods including their specific detection limits, a reference work, Analytical Methods for Environmental Water Quality Dictionary, has been developed. It contains a compilation of methods already used for data collection by the participating countries and institutions. Its current version comprises information on procedure, units, number of decimal places and literature references. The methods are referenced in the GEMStat database via an index. The latest version of the document can be found in the download area.Download PDF
The water quality data available in GEMStat can be used for status evaluation, research purposes or within the scope of education and training initiatives.
The data contained in the GEMStat database are the property of the respective data providers. Interested parties are therefore invited to submit a written request stating the planned data use and application to .
Most of the GEMStat data sets, maps and posters are freely available for download by users. GEMS/Water does not place any restrictions on the use of these data, but does request that users cite UNEP GEMS/Water Programme (and any other sources mentioned in the documentation of the data provided) as data provider(s). Users of data sets supplied through GEMStat are requested to incorporate in their products and reports acknowledgements to the originator of the data and to the fact that they were acquired through UNEP GEMS/Water Programme.
Users do not obtain title to the intellectual property of the data held in this website, nor any copyright or propriety rights to its content. As the data provided are the intellectual property of the organisations which supplied the information, the original source of the data must be fully acknowledged. Please refer to the respective organisations for further inquiries regarding copyright and user limitations.
Users are not allowed to transfer, sublicense, rent, lease or sell the data herein.
For data sets not available on-line, requests made by non-commercial and non-private persons (i.e. those with no affiliation) will be filled at no cost, but will depend on data availability, UNEP GEMS/Water Programme workload and the nature of the data set/product being requested.
Requests will be queued with priority given to those related to joint activities with UNEP programme areas and other UN agencies. Data sets with a “restricted access” rating will not be distributed; however, information about such data sets, including the distributor’s name, will be sent to eligible institutions upon request.
Cite Data as:
United Nations Environment Programme (2017). GEMStat database of the Global Environment Monitoring System for freshwater (GEMS/Water) Programme. International Centre for Water Resources and Global Change, Koblenz. Accessed DD MONTH YYYY. Available upon request from GEMS/Water Data Centre:
Global Water Quality information System GEMStat
The GEMS/Water Data Centre implements further data analyses and evaluations. The results can be retrieved by the users. At present, previous products are being revised and adapted. Information on statistical evaluations, maps and the expert system for load estimation (Loading Estimate Guide) is continuously updated.
The water quality index suggested by Carr & Rickwood has been integrated into the Environmental Performance Index (EPI) in 2008. It is based on a “proximity to target“ approach, estimating the quality of all inland waters with regard to human and ecosystem health. Various parameters are consulted during this analysis.
Based on this work, the indicator for monitoring the water quality of the sustainable development goal (SDG) 6.3.2 has been developed within the scope of the GEMI network.
GEMI, the cross-sectoral initiative on the coherent monitoring of the sustainable development goals, operates under the auspices of UN-Water.
Focusing on water, wastewater and sanitation, GEMI will establish guidelines on monitoring the goals 6.3 to 6.6, while offering the member states support in developing relevant capabilities. This is in support of existing initiatives.
GEMS/Water and the Federal Institute of Hydrology (BfG) will mainly contribute to developing the indicator 6.3.2. It is defined as share of water bodies (area) in a country with a good water quality compared to all water bodies.
A one-year pilot service providing satellite monitoring for GEMStat, using the Copernicus programme’s Sentinel satellites, is being installed. The resulting and checked products will be integrated into the GEMStat database.
The two-year SPONGE programme is part of the ESA Data User Element Innovators III projects. SPONGE is to demonstrate simplifications of the information management within the UN Water Community, of which GEMS/Water is a member. The project is headed by Odermatt & Brockmann Co. in Zurich (Switzerland).
Further information on SPONGE:www.odermatt-brockmann.ch/sponge
The WWQA project aims at identifying areas with current or future problems associated with freshwater quality as well as analysing options for action. The GEMS/Water Data Centre provides measured data from the GEMStat database to perform these tasks.
The assessment of the global water quality (World Water Quality Assessment, WWQA) is directed by UNEP in cooperation with GEMS/Water, and the Helmholtz Centre for Environmental Research (UFZ) in Leipzig. The Center for Environmental Systems Research (CESR) in Kassel is responsible for the analyses.
The GEMS/Water programme was founded as a global network for water quality monitoring in 1978. Under the auspices of UNEP, the United Nations Environment Programme, GEMS involves the World Health Organisation (WHO), the World Meteorological Organisation (WMO) and UNESCO. The programme has been restructured and reorganised in 2014.
The GEMS/Water Programme aims at improving water quality monitoring in freshwater ecosystems. The data and information on water quality provided by participating countries provide a global overview of the condition of water bodies and statements on changes and trends at global, regional and local levels.
In February 2011, the UNEP Governing Council called on the governments and organisations in the member states to participate in the GEMS/Water Programme. The first UN Environment Assembly (UNEA) in July 2014 recommended GEMS/Water as a supporting mechanism to monitor the Sustainable Development Goals (SDGs). Special focus is on sub-target 6.3, aiming at improving water quality, and the corresponding indicator 6.3.2.
The GEMS/Water Programme comprises the following elements:
- Global Programme Coordination Unit (GPCU)
GPCU, located at the UNEP Division of Early Warning (DEWA) in Nairobi/Kenya, is responsible for the overall coordination of the programme and for providing information to decision-makers.
- GEMS/Water Capacity Development Centre (CDC)
- GEMS/Water Global Data Centre (DC)
The data centre of GEMS/Water is based on a treaty between UNEP and the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety. It is located at the Federal Institute of Hydrology in Koblenz.
- Regional Hubs
At the regional level, several Regional Hubs are planned to support the GEMS/Water Programme in communicating with the partners and in implementing programme activities especially in the field of capacity development in the individual regions. Currently, one Regional Hub for Latin America, the Caribbean and Portuguese-speaking countries has been established at the National Water Agency (ANA) of Brazil.
- Global Network
The worldwide GEMS/Water network currently comprises more than 80 countries with more than 3000 stations. The water quality data are provided by National Focal Points located at government authorities, and by Collaborating Focal Points from scientific and other institutions.