Surface and groundwater stable isotope analysis using water samples taken from the Gandak River Basin, Bihar, India, 2017-2019

Stable isotope values for 108 water samples collected in the Gandak River Basin, in Bihar, India are presented, with accompanying values for SEC (specific electrical conductivity) for most of these samples. Samples were collected between February 2017 and February 2019, of surface water, groundwater and rainfall. Most groundwater samples were sampled from boreholes or wells that were in regular daily use. Samples were unfiltered and were bottled at source in Nalgene sample bottles, filled to brim to avoid air, and labelled at source. SEC was measured at source using a field SEC meter. Samples were analysed for the stable isotopes deuterium and oxygen-18 by mass spectrometry, at British Geological Survey laboratories in the UK. Further details can be found in the supporting information.

Samples were taken by staff from the British Geological Survey, Imperial College London, Tilka Manjhi Bhagalpur University, Bihar and Ashoka Trust for Research in Ecology and the Environment (ATREE).

The data were collected as part of the NERC sponsored project Coupled Human and Natural Systems Environment (CHANSE), grant number NE/N01670X/1.