Resumen
In this series of articles, complete NH3 and NOx emission inventories have been calculated for the first time for Galicia (NW Spain), a region in serious danger due to the eutrophication produced by these emissions. In this first part, NH3 emissions corresponding to main sources (from agricultural and non-agricultural activities) have been estimated and the associated uncertainties have been quantified. The results have shown that livestock emissions (particularly by broilers and cattle) are especially relevant in this region, representing almost 90% of the total, the use of fertilizers being the second source in importance, while all the non-agricultural sources as a whole contribute less than 4%. The study of uncertainties has shown that future research in the region has to focus on the development of more specific emission factors for agricultural sources (especially for cattle, broilers and urea) to reduce this uncertainty.