Abstract
Dry deposition velocities of SO2 to various model surfaces were calculated from total flux of SO2 and SO42- measured on their surfaces assuming that dry deposition velocities of SO42- to various surfaces were 1/5 as large as SO2. Estimated dry deposition velocities of SO2 to water, soil, vegetation and building material surfaces ranged 0.01∼0.64 cm·s-1. The results of spatial distribution for dry deposition flux of sulfur estimated with dry deposition velocities of SO2 has indicated that the average value in 1995 was 9.4 gS·m-2·y-1. Considerably high the values over 12.5 gS·m-2·y-1 were estimated for urban, Banan and Nantong area where large amounts of SO2 had been emitted by coal combustion. In spite of the lowest dry deposition flux (4.4 gS·m-2·y-1) over Tongliang area, it was 2.2 times as high as that of Tokyo, Japan (2.0 gS·m-2·y-1). Higher dry deposition flux over eastern area than western area must be caused by the difference of weather, geographical conditions and sulfur emission. During 1986∼1995, the average dry deposition for sulfur accounted for 67% of sulfur emission in Chongqing. This result indicated that the difference between dry deposition and emission was deposited as precipitation and transported to other area.
