Quantification of eutrophic aerial compounds in Galicia (NW Spain): Part 2 – NOx inventory

Abstract

This study is the second part of a series where NH₃ and NO_x emission inventories for Galicia (NW Spain), a region with a great risk of eutrophication, have been developed. The principal sources of NO_x emissions in Galicia and their associated uncertainty have been calculated in this paper. The results prove that industrial and mobile sources produce 90% of the emissions, principally due to road transport, power and cogeneration plants. Use of fertilizers or fuels for residential purposes, burning of agricultural waste, soils, fires and lightning are minor sources of emissions. In the case of fires, in regions specially affected like Galicia, attention must be paid to variations in number and type of burnt areas from one year to another, because it can significantly change total NO_x emissions. The emissions produced by agricultural, fishery and forest vehicles and machines as well as by maritime and railway traffic are the main focus of uncertainty due to the lack of specific data for Galicia like type, age and power of the machines. Other important focuses of uncertainties are the emissions from soils and fires owing to the absence of a more specific methodology.