中国南方典型地区油-稻轮作条件下大气SO2干沉降速率动态变化

以1998年11月～1999年10月中国科学院红壤生态试验站农田小气候观测站气象梯度资料(温度、风速、气压)，计算近地面湍流特征参数(u^*、θ^*、L)，然后采样阻力模式计算SO2干沉降速率(Vd)。研究了该地油-稻轮作条件下大气SO₂干沉降Vd动态变化．结果表明，一年中大气SO2干沉降Vd时平均年均值为0．124～0．897cm·s^-1(mean±SE=0．507±0．167cm·s^-1)．一年中大气SO2干沉降Vd存在如下规律性：白天>晚上．3～8月份SO2Vd平均值(0．611cm·s^-1)大于9～12、1～2月份SO2Vd平均值(0．401cm·s^-1)．水稻生长期间(0．605±0．093cm·s^-1)>油菜(0．491±0．166cm·s^-1)>休闲(0．342±0．174cm·s^-1)．

Dynamics of dry deposition velocities (Vd) of atmospheric SO2 on rapeseed/rice rotation systems in selected area of South China

With the profile meteorological data collected from the farmland micro-meteorological experimental substation, Experiment Station of Red Earth Ecology, Yingtan, Jiangxi, Chinese Academy of Sciences during rapeseed/rice rotation from Nov. 1998 to Oct. 1999, the surface layer turbulence characteristic parameters (u*, theta*, L) and the atmospheric SO2 dry deposition velocities (Vd) were calculated. The results indicated that the hourly mean Vd of SO2 dry deposition was ranged from 0.124 to 0.897 cm.s-1 (mean +/- SE = 0.507 +/- 0.167 cm.s-1), and its regular dynamic pattern was as follows: it was always higher at daytime than at night, and the mean Vd of SO2 dry deposition during March-August(0.611 cm.s-1) was obviously greater than that during Sept.-Dec. and Jan.-Feb. (0.401 cm.s-1). The mean Vd of SO2 dry deposition during various crop growth stages was decreased as the order of rice (0.605 +/- 0.093 cm.s-1) > rapeseed (0.491 +/- 0.166 cm.s-1) > follow (0.342 +/- 0.174 cm.s-1).