Fig. 4
From: Entropy and seasonal isotopic duality reveal the sustainability paradox of the upper Ganga River
Stable isotope process diagnostics and seasonal water quality assessment. In (e–f), monsoon samples are solid circles and post-monsoon are hollow circle while from (a-d, g–l), monsoon panels have transparent backgrounds and post-monsoon panels are grey-shaded. (i) (a–b) δ¹⁸O–δD relationships with altitude effects, (c–d) δ¹⁸O versus elevation illustrating systematic depletion upstream, e) d-excess versus δ¹⁸O illustrating evaporative modification and moisture source variability, (f) d-excess versus Cl⁻ indicating evaporation-driven solute enrichment, (g-h) d-excess versus TDS for highlighting seasonal evaporative concentration effects, (i–l) Coupling of δ18O with HCO3− and NO3− highlighting anthropogenic imprints. (ii) EWQI values for monsoon and post-monsoon samples.
