Tracing the Origin of Groundwater Nitrate in an Area Affected by Acid Rain Using Dual Isotopic Composition of Nitrate

Figure 2

Precipitation ion compositions (% in meq/L). The ion compositions are the weighted average values from Jinyunshan, Beibei District, Chongqing, from 2013 to 2017. SO₄^2-, NO₃^-, Ca²⁺, NH₄⁺, and H⁺ are the main ions in precipitation (>15%). The data are from [9].