The Distributional Characteristics of Ions in the Bulk Precipitation and the Forested Throughfall in Shaoshan,Hunan Province

The distributional characteristics of chemical compositions of the bulk precipitation and the forested throughfall in Shaoshan area are summarized based on the monitoring data from January 2001 to June 2002.The results show that the dominant anion is SO\-4\+\{2-\} both in the bulk precipitation and the forested throughfall,accounting for 5287% and 4892% respectively,and the dominant cation is Ca\+\{2+\},accounting for 3762% and 42\^81% respectively.The ion concentrations in the forested throughfall significantly increase.Compared to the bulk precipitation,the largest concentration of ions increases up to 9\^7 times in the forested throughfall.The chemical constituents of the bulk precipitation and the forested throughfall are analyzed using the principal component analysis to find the possible sources of the measured chemical species.Two major componets that account for 92\^76% in total variance are extracted in the bulk precipitation and three major components that account for 96\^70% in total variance are extracted in the forested throughfall.