Atmospheric S and N deposition relates to increasing riverine transport of S and N in southwest China: Implications for soil acidification. (November 2016)

• Record Type: Journal Article
• Authors: Duan, Lei; Chen, Xiao; Ma, Xiaoxiao; Zhao, Bin; Larssen, Thorjørn; Wang, Shuxiao; Ye, Zhixiang
• Is Part Of: Environmental pollution. Volume 218(2016)
• Page Start: 1191
• Page End: 1199
• Publication Date: 2016-11
• Subjects: Sulfur budget -- Nitrogen budget -- Acidification -- Sulfate adsorption -- N saturation; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2016.08.075
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Following Europe and North America, East Asia has become a global hotspot for acid deposition, with very high deposition of both sulfur (S) and nitrogen (N) occurring in large areas of southwest and southeast China. This study shows that the outflow flux of sulfate (SO4 2− ) in three major tributaries of the Upper Yangtze River in the Sichuan Basin in southwest China has been increasing over the last three decades, which implies the regional soil acidification caused by increasing sulfur dioxide (SO2 ) emissions. Since 2005, the outflow of SO4 2− to the Upper Yangtze River from the Sichuan Basin has even reached the atmospheric SO2 emission from the basin. In contrast to S emissions, the rapid increase in nitrogen (N) emissions, including nitrogen oxides (NOx) and ammonia (NH3 ), have resulted in only a slight increase in nitrate (NO3 − ) concentrations in surface waters, indicating a large retention of N in the basin. Although N deposition currently contributes much less than S to soil acidification in this area, it is possible that catchments receiving a high input of N may be unable to retain a large fraction of the N deposition over long periods. Graphical abstract: Highlights: The SO4 2− outflow flux from the Sichuan Basin is well-balanced with S deposition in the basin. The increasing SO4 2− outflow in the Yangtze River implies regional soil acidification. Nitrogen deposition currently contributes much less than S deposition to soil acidification. Abstract : The S and N budgets for Sichuan Basin, a very large catchment were preliminarily set up, which indicate regional soil acidification in southwest China.