WQ4Nile: Water Quality Data for the Nile Basin

Overview This dataset was compiled to support the analysis of water quality monitoring data across the Nile Basin. It harmonizes and integrates observations from the FreshWater Watch programme, the UNEP GEMS/Water Global Freshwater Quality Archive (GEMStat), and several academic publications. The resulting database combines water quality measurements, metadata, sampling dates, monitoring locations, and subbasin classifications for sites located within the Nile River Basin. Data sources FreshWater Watch Global_Data_Set_XvsX_0.csv contains worldwide citizen-science water quality observations. The dataset includes measurements of approximately 140 parameters and 72,207 observations from monitoring sites across multiple countries. FreshWaterWatch_Input.csv served as the basis for the construction of the master database. Only variables relevant for the present study were retained and harmonized. Selected parameters were renamed to standardized variable names. In addition, a unique `Site_ID` identifier was assigned to each monitoring location. The original dataset is available at https://www.freshwaterwatch.org/pages/explore-our-data UNEP GEMS/Water Global Freshwater Quality Archive (GEMStat) The complete GEMStat archive contains more than 20 million measurements for 608 water quality parameters collected at 13,660 monitoring stations in 37 countries between 1906 and 2023. Data are provided by National Hydrological Services of UN member states. For the present project, only monitoring stations located within the Nile Basin and its subbasins were selected. Water quality measurements and associated station metadata were extracted and integrated into the master database. The original dataset is available at https://doi.org/10.5281/zenodo.13881899 Academic publications Additional water quality datasets were compiled from 21 peer-reviewed academic publications published 2007-2025 covering different regions of the Nile Basin. These datasets were harmonized and integrated to create a comprehensive basin-wide water quality database. Derived datasets/data files In4Nile_Metadata_Sources.csv - This metadata table provides detailed information on all literature and data sources used in the development of the IN4Nile database. For each source, metadata such as author(s), publication year, title, DOI, and source type are included where available. In4Nile_Metadata_Parameter.csv - This metadata table contains a comprehensive list of all water quality parameters included in the IN4Nile Master Data table. For each parameter, the file provides the parameter name, description, and additional information required for interpretation. This metadata table supports consistent parameter definitions across the harmonized database and facilitates data analysis and comparison between different sources. It additionally contains all columns used in the other metadata files and respective explanations. In4Nile_Metadata_Sampling_Sites.csv - This metadata table contains essential site-specific information for all sampling locations included in the database, such as site identifiers, site names, and geographic coordinates. In4Nile_Master_Data.csv - This data table contains the harmonized master dataset containing all collected measurements and more than 220 water quality, ecological, and environmental parameters compiled from the different data sources. Repository contents The repository includes: 1. Harmonized water quality observations from FreshWater Watch, GEMStat, and several academic publications. 2. Metadata describing monitoring sites. 3. Subbasin information for all monitoring sites within the Nile Basin. 4. Source information providing the origin of each observation. 5. Temporal information derived from sampling dates. License This dataset is released under CC BY 4.0. The license applies to our compiled, harmonized, curated, and documented dataset, including metadata. The dataset partially contains water-quality data extracted from cited scientific publications. Copyright in the original articles, including text, figures, publisher-formatted tables, and layouts, remains with the respective rightsholders and is not licensed by us. We urge all users of this data base to acknowledge and cite individual publications where applicable. Note that the provided data were created with greatest care, but we cannot guarantee correctness of the data.