Dissolved Gaseous Mercury (DGM) Flux at the Water/Air Interface over The Negro River Basin, Amazon, Brazil

摘要

The amount of dissolved gaseous mercury (DGM) released annually to the atmosphere by water bodies in each of the 18 major sub-basins of the Negro River tributaries has been estimated for the wet season. Using Remote Sensoring (RS) and Geographic Information System (GIS), the total flooded area was estimated during the wet season period (May-July), being its maximum value around 10 percent of the total basin area. DGM evasive fluxes values estimated in the last 4 scientific excursions varied between 0.45 and 7.9 pmol m~(-2) h~(-1). Considering the flooded area of the Negro River Basin as 69,000 km~2, the total amount of mercury emitted by all water bodies reaches nearly 0.26 ton y~(-1), what represents not more than 2 percent of the total mercury found in the wet deposition in this same area.