Abstract The isotopic compositions of oxygen ( δ 18 O) and hydrogen ( δ 2 H) are widely used to locate the geographical origin of biological remains or manufactured products. In this paper, we analyse the distributions of δ 18 O and δ 2 H in tap waters sampled across France, and in precipitation interpolated with the Online Isotopes in Precipitation Calculator and modelled with the isotope-enabled ECHAM6-wiso model. Our aim is to provide isoscapes usable in archaeology and forensics and evaluate whether the modelled data could be surrogates for measured ones. The δ 18 O and δ 2 H in the 396 tap waters sampled varied spatially within a range of 10‰ and 77‰, respectively. Their consistent distributions followed rules summarized by the effects of altitude and distance from the coast. Their variations along the year were small. Therefore, the database provides a solid reference for δ 18 O and δ 2 H of the water supply system at the regional scale. The areas with the most uncommon oxygen and hydrogen isotopic compositions (Atlantic coast south of Brittany and the highest elevations in the Alps) are the most accurately traceable areas in provenancing studies. The isotopic compositions of modelled precipitation have the same spatial distributions but different absolute values from those of tap waters. Therefore, our results favour the use of statistical isoscapes rather than general circulation model-based isoscapes in provenancing studies.

Abstract To investigate the influence of local climate and transboundary circulation of moisture on the stable isotope of precipitation in Ramnicu Valcea, Romania, monthly values of δ 2 H, δ 18 O, deuterium excess (d excess ), temperature, relative humidity and precipitation were determined between January 2012 and December 2018. Monthly analysis showed differences in d excess varying between 24.2‰ (October 2015) and −23.7‰ (July 2013) with a multi-annual average of 6.1 ± 5.9‰, suggesting an Atlantic origin of moisture with episodic Mediterranean transport. Also a significant correlation between the North Atlantic Oscillation on the local temperature during winter season was noticed. The local meteoric water line (LMWL) for the entire period showed slope and intercept values similar to those for neighbouring localities with the same altitude. When the analysis was extended to summer (April–October) and winter (November–March) seasons, the LMWL slope and intercept were different, reflecting the summer–winter difference in temperatures and air circulation. The monthly values of all parameters formed equal-spaced time series whose detailed analysis confirmed at p < 0.01 that δ 2 H, δ 18 O, temperature and relative humidity show a well-evidenced one-year periodicity. In contrast, precipitation and d excess seasonality were almost unrecognizable, most probably owing to the reduced number of observations.

Abstract The isotopic composition of water has been widely used to investigate groundwater dynamics and recharge processes. In the present study, we have analysed the isotopic composition of groundwater, and of Sutlej River, Yamuna River, Ghaggar River and canal water from the Sutlej-Yamuna plain in NW India. We document spatial and depth-related variations in δ 18 O and deuterium excess (d-excess) values of groundwater in three zones based on topography and slope (zones I–III) from NE to SW. In Zone I, precipitation is the main recharge source for groundwater, as indicated by the isotopic values. We infer mixed recharge from precipitation and irrigation return flow in Zone II. Zone III records depleted δ 18 O and higher d-excess values in most of the groundwater samples, suggesting active recharge from canals. Further, we have calculated the contribution of canal water in groundwater using the hydrograph separation approach and have also quantified the uncertainty in its estimation. We note significant spatial and depth-related variability in the canal water contribution to groundwater recharge. The canal contribution is as high as 83 ± 10% at 18 m below ground level (bgl) in Zone III, and as low as 5 ± 3% at 43 m bgl in Zone II. The present study provides the baseline data on recharge processes in NW India, which is critical for developing sustainable management strategies for groundwater resources in this region.