Custom data request

Water quality data available from GEMStat can be used for status evaluation, research purposes or within the scope of education and training initiatives.

For data sets not available online through the Data Portal or Statistics Portal, 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, UN Environment 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 UN Environment 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 and summary statistics on country level, can be sent to eligible institutions upon request.

Data policy

Users do not obtain title to the intellectual property of the data provided by GEMStat, nor any copyright or propriety rights to its content. As the data provided are the intellectual property of the organizations which supplied the information, the original source of the data must be fully acknowledged. Please refer to the respective organizations for further inquiries regarding copyright and user limitations.

Users are not allowed to transfer, sublicense, rent, lease or sell the data herein. The overall conditions for requesting data from GEMStat are summarized within a user declaration. Users are required to submit a scan of the signed user declaration with their data request in order to proceed.

Download User declaration (PDF-File, 16KB)

Information for custom data requests

In order to file a data request, please send an email to including the following information:

  1. Your contact details, affiliation and intended use of the requested data
  2. Description of the required water quality data, including
    • Required parameters or parameter groups
    • The monitoring locations or countries, for which the water quality data should be exported
    • The years for the beginning and end of the requested data
    • The desired format of the requested data (raw data or aggregated statistics)
  3. Carefully read and sign a printout of the user declaration and attach a scan of the signed document.
  4. Please keep in mind that if you publish any reports or other products based on the data from GEMStat, you are requested to acknowledge the originators of the data and the fact that they were acquired through UN Environment GEMS/Water Programme.

Please cite the data acquired from GEMStat as follows:

United Nations Environment Programme (2018). 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: gemstat.org

You can get an overview of the monitoring locations and parameters available within GEMStat with the help of the Data Portal as well as our Parameter and Station catalogues:

Download Station catalogue (XLS-File, 1,3MB)
Download Parameter catalogue (XLS-File, 140 KB)

Parameter Catalogue

The Parameter Catalogue summarizes all the water quality parameters that are available in GEMStat. It organizes the water quality parameters in three hierarchical groups, loosely based on the CUAHSI-Ontology (http://edscvs.ccny.cuny.edu/cuahsi/index.php?tema=1), and provides the user with a description for almost every parameter in the database.

It offers a convenient filter for every column, which allows for narrowing down the shown parameters according to the selected criteria: Simply click on the small triangles that can be found at the right edge of every column header, and restrict the selection to the entries that you are most interested in. If you, for instance, wish to see only the water quality parameters that are classified as nutrients, click on the triangle in column “Group 2” and deselect all entries except “Nutrient”.

Download Parameter catalogue (XLS-File, 140 KB)
 DescriptionExample
Group 1Main group of the water quality parameter.
(Biological, Chemical and Physical)
Chemical
Group 2Secondary group of the water quality parameter. Nutrient
Group 3Tertiary group of the water quality parameter with the highest granularity. Some entries from Group 2 may repeat themselves in this group.Nitrogen
Parameter nameGeneral name of a water quality parameter, irrespective of actual speciation.Organic Nitrogen
Parameter long nameComplete parameter name, including speciation. For complex chemical compounds usually the IUPAC name is used (if sufficiently concise).Total Organic Nitrogen
Parameter codeGEMS code of water quality parameter that is used for unique identification of a given water quality parameter and its species in the GEMStat database.TON
RemarkShort description of the water quality parameter. For complex chemical compounds, this includes the empirical formula and optionally the IUPAC name (if too expansive for the "Parameter Long Name" column).
Number: CASCAS registry number (https://www.cas.org/content/chemical-substances)
7727-37-9
Number: ECEC registry number
(https://echa.europa.eu/information-on-chemicals/ec-inventory)
231-783-9
Number: ChEBIChEBI registry number
(https://www.ebi.ac.uk/chebi/)
25555

Station Catalogue

The Station Catalogue provides the user with an overview of all monitoring locations that are registered in GEMStat.

The worksheet “Map” offers an overview of the global distribution of monitoring locations and their type.

The worksheet “Stations” presents a table with all relevant information for every single monitoring location, together with Latitude and Longitude coordinates to allow the user to plot the locations with the help of a GIS-software.

It offers a convenient filter for every column, which allows for narrowing down the shown monitoring locations according to the selected criteria: Simply click on the small triangles that can be found at the right edge of every column header, and restrict the selection to the entries that you are most interested in. If you, for instance, wish to see only monitoring locations that are located in the Indus basin, click on the triangle in column “Catchment_name” and deselect all entries except “Indus”.

Download Station catalogue (XLS-File, 1,3MB)
 DescriptionExample
Country_codeISO 3166-1 ALPHA-3 code of country, where the station is located.DEU
Station_numberInternal code of the monitoring location in GEMStat.DEU00005
Station_characteristicType of water body, at which the monitoring location is situated.RIVER
Monitoring_typeType of monitoring activity:
Baseline - determination of natural freshwater qualities in the absence of significant direct human impact
Trend - determination of long-term trends
Impact - determination of short term impacts of potential sources on water quality
Flux - determination of the fluxes of toxic chemicals, nutrients, suspended solids and other pollutants from major river basins to the continent/ocean interfaces
TREND
Catchment_nameName of major river basin (river with highest Strahler-order), where the monitoring location is situated.Rhine-Meuse
Station_nameName of the monitoring location.Moselle River - at Koblenz/Moselle
RemarkDescription of monitoring location and special conditions.2 km upstream of the confluence with the Rhine River
LatitudeCartesian y-Coordinates in WGS84 coordinate reference system.50.35
LongitudeCartesian x-Coordinates in WGS84 coordinate reference system.7.552778
HeightFor surface waters: mean elevation of water surface above mean sea level.
For groundwaters: ground elevation above mean sea level.
135
Old_GEMS_numberHistorical GEMS code of monitoring location, as in use prior to 2014.135005