The Surface Water Chemistry (SWatCh) database: a standardized global database of water chemistry to facilitate large-sample hydrological research

[摘要] Openly accessible global-scale surface water chemistrydatasets are urgently needed to detect widespread trends and problems, tohelp identify their possible solutions, and to determine critical spatial datagaps where more monitoring is required. Existing datasets are limited with respect toavailability, sample size and/or sampling frequency, and geographic scope. Theselimitations inhibit researchers from tackling emerging transboundary water chemistryissues – for example, the detection and understanding of delayed recoveryfrom freshwater acidification. Here, we begin to address these limitationsby compiling the global Surface Water Chemistry (SWatCh) database, availableon Zenodo ( https://doi.org/10.5281/zenodo.6484939 ; Rotteveel and Heubach, 2021). We collect, clean, standardize, andaggregate open-access data provided by six national and internationalprograms and research groups (United Nations Environment Programme; Hartmannet al., 2019; Environment and Climate Change Canada; the United States ofAmerica National Water Quality Monitoring Council; the European EnvironmentAgency; and the United States National Science Foundation McMurdo DryValleys Long-Term Ecological Research Network) in order to compile a databasecontaining information on sites, methods, and samples, and a geospatialinformation system (GIS) shapefileof site locations. We remove poor-quality data (e.g., values flaggedas “suspect” or “rejected”), standardize variable naming conventions andunits, and perform other data cleaning steps required for statisticalanalysis. The database contains water chemistry data for streams, rivers,canals, ponds, lakes, and reservoirs across seven continents, 24 variables,33 722 sites, and over 5 million samples collected between 1960 and 2022.Similar to prior research, we identify critical spatial data gaps on theAfrican and Asian continents, highlighting the need for more data collectionand sharing initiatives in these areas, especially considering that freshwaterecosystems in these environs are predicted to be among the most heavilyimpacted by climate change. We identify the main challenges associated withcompiling global databases – limited data availability, dissimilar samplecollection and analysis methodology, and reporting ambiguity – and providerecommended solutions. By addressing these challenges and consolidating datafrom various sources into one standardized, openly available, high-quality,and transboundary database, SWatCh allows users to conduct powerful androbust statistical analyses of global surface water chemistry.

[学科分类] 眼科学