Identification of the sources and fate of NO3−-N in shallow groundwater around a plateau lake in southwest China using NO3− isotopes (δ15N and δ18O) and a Bayesian model

Pollution by NO3−-N seriously threatens the quality of shallow groundwater (SG) around Erhai Lake, which is the 2nd largest source of freshwater in the plateau area in southwest China; further, NO3−-N affects the lake water quality and human health. We collected SG samples during the dry and wet seasons in 2018 and 2019, and the potential NO3−-N sources and their fates were identified in SG by NO3− isotopes and hydrochemical methods. Our results...