Deposition Patterns of SO4 2- NO3 - and H+ in the Brazilian Territory

SO₄2- NO₃- and H+ depositions are estimated in the Brazilian territory based on the existing rainfall chemical data and on annual rainfall distribution over the whole territory. Local and regional depositions are estimated. Rainfall chemical data over the Brazilian territory shows that the average pH values are usually low (between 4.0 and 5.5). These values are observed in the tropical Amazon forest as well as in urban areas. However, the rainwater acidity in the tropical forests are due to organic acids naturally produced by the vegetation while in urban areas the acidity is mainly due to acidic anion deposition (NO₃- and SO₄2-). In some Amazonian areas, the average input values through rainfall for NO₃- is about 0.06 keq.ha.yr-1 and for SO₄2- is between 0.23 and 0.54 keq.ha-1.yr-1. On the other hand, in some urban centers, such as São Paulo, values of .072 keq.ha-1.yr-1 for NO₃- and 1.16 keq.ha-1.yr-1 of SO₄2- are found and in sites where sulfate sources (coal mining) are present, as for the area of Florianópolis, values as high as 5.59 keq.ha-1. yr-1 for SO₄2- are found.