GEMStat hosts a large variety of water quality data from countries worldwide. The regional subdivision follows the classification of UNEP-Regions (i.e. where the United Nations Environment Programme has Regional Offices).
In the following you find background information about the geographic and temporal coverage of GEMStat as well as available station types and parameters.
The Global Environment Monitoring System for Freshwater (GEMS/Water) was founded as a global network for water quality monitoring in 1978. Overall, data is available for the time period from 1965 to 2019, covering a total time frame of 54 years. The longest time series are currently available from Europe, North America and Asia and the Pacific.
Parameters in GEMStat are classified following the CUAHSI Hydrosphere Ontology. In total, about 300 parameters are available, which are classified into a hierarchical system of groups and subgroups.Download Parameter catalogue (XLS-File, 140 KB)
Currently, most GEMStat data falls within the category chemical parameters, followed by physical parameters, while biological parameters represent only a minor proportion. The largest proportion is thereby contributed by inorganic compounds and nutrients.