Groundwater Isoscape for India (δ¹⁸O, δD, d-excess)

This dataset provides gridded stable isotope compositions (δ¹⁸O, δD, and d-excess) of groundwater across India at 0.25° × 0.25° spatial resolution. The data were generated using kriging-based geostatistical interpolation of 5,928 groundwater samples collected from diverse climatic regions across India, compiled from 20 independent sources. Each raster is stored as a GeoTIFF file in WGS84 coordinates (EPSG:4326). Uncertainty (standard deviation) layers accompany each isotope map. These data support an upcoming manuscript, "Are groundwater isotope linearly associated with climateic and geographical variables? An invedstigation using the Generalised Additive Model" intended for submission to Journal of Hydrology, and are publicly available for open scientific use and citation. File Overview: o18.tif — Oxygen isotope composition (δ¹⁸O, ‰, VSMOW) o18_sd.tif — Standard deviation (uncertainty) for δ¹⁸O dD.tif — Hydrogen isotope composition (δD, ‰, VSMOW) dD_sd.tif — Standard deviation (uncertainty) for δD d-excess.tif — Deuterium excess (δD – 8 × δ¹⁸O, ‰) d-excess_sd.tif — Standard deviation (uncertainty) for d-excess Dataset Information: Field Details Format GeoTIFF (.tif) Projection EPSG:4326 (WGS84) Spatial Resolution 0.25° (~27 km) Extent 68.12°E – 97.37°E, 6.75°N – 37.00°N Variables δ¹⁸O, δD, d-excess, and respective SD layers Units per mil (‰, relative to VSMOW) NoData Value NaN Data Type Float32 Usage Notes:The rasters can be visualized and analyzed using GIS software (QGIS, ArcGIS) or Python libraries such as rasterio, xarray, and matplotlib. The uncertainty layers quantify the spatial prediction error from the kriging interpolation. Embargo Information:The dataset is currently restricted. Citation:Sarkar, M., et al. (2025). Groundwater Isotope Raster Maps for India (δ¹⁸O, δD, d-excess) [Data set, Version 2]. Zenodo. https://doi.org/10.5281/zenodo.17472967