Characteristics and Variations Analysis on Chemical Composition of Atmospheric Precipitation of Kunming

In order to examine the chemical characteristics and variations of atmospheric precipitation of Kunming, the parameters of rainfall, pH, electrical conductivity and concentrations of anions(SO₄^2-, NO₃^-, Cl^-,F^-) and cations (K⁺, Na⁺, Ca²⁺, Mg²⁺, NH₄⁺)were analyzed with samples collected from January to December2019. The results indicated that the rainfall was mainly concentrated from June to October in 2019 with 87.6% of the whole year. There was no acid rain during the whole year, because the range of pH values was from 6.93to 7.70. SO₄^2- was the major anion with 53.7% of the total ions while Ca²⁺ was the main cations with 65.4% of all.Compared to 2018, the concentration of SO₄^2- reduced while the concentration of Ca²⁺ increased significantly.