A global dataset of groundwater nitrate concentration from 1979–2022

This study presents a global nitrate concentration dataset with annual temporal resolution. The dataset integrates publicly available groundwater quality databases and data compiled from 190 published studies over the past two decades. Based on this compilation, a decadal dataset of mean nitrate concentrations for the 1980s–2010s was further derived at the aquifer scale using an Interquartile Range (IQR)-based Winsorization procedure. These datasets support the assessment of global groundwater nitrate dynamics and related management efforts. The final data product consists of two components. The first is a global nitrate concentration dataset comprising 167,152 measurements from 40,913 locations during 1979–2022. The dataset is provided in .xlsx format, with each record including seven fields: ID, latitude, longitude, year, nitrate concentration (mg L⁻¹), study area, and data source. Reference information for the data sources is provided in Measured nitrate dataset references.docx. The second component is a decadal dataset of aquifer-based mean nitrate concentrations for the 1980s–2010s. This dataset includes four raster files (.tif) representing decadal mean nitrate concentrations (mg L⁻¹) and one raster file defining the global aquifer zonation. Detailed descriptions of these files are provided in Dataset Description.docx.