Application of a LRT model to acid rain control in China

For further control of acid rain and SO2 pollution in China, acid rain control zones and sulfur dioxide pollution control zones were designated where acid rain or serious SO2 pollution occurs or may occur. In this study, sulfur deposition in east China was computed through a policy-oriented, two-dimensional Eulerian model for long-range transport and deposition of SO2 and SO4(2-). The model predictions were in accordance with the wet deposition monitored. Results show that concentrations of SO2 and SO4(2-) are higher in north China than those in the south, and high deposition of sulfur occurs in most areas of North China, in the lower reaches of the Changjiang (Yangtze) River and around Chongqing and Guiyang in southwest China. Total emission of SO2 from the modeling region (from 19 degrees N to 42 degrees N, and from 104 degrees E to 124 degrees E) was about 20 million tons in 1995. The model predicts that 48% of this deposits within the region as dry deposition, 38% deposits as wet deposition, and only about 14% was transported out of the region. The modeling results of sulfur deposition were directly applied in designating acid rain control zones in China, and the emission-deposition relationship derived was also used to formulate middle- and long-range planning programs for regional acid rain control in China.