近地面大气汞的垂直分布

以金粒管富集气汞法研究了蔬菜地、农田、果园、林地等植被类型的近地面气汞的分布特性。结果表明，在近地面0cm,50cm,100cm,150cm4个层次的气汞浓度平均值菜地以50cm层次气汞浓度最高，显著高于贴地面的气汞浓度；油菜地、果园及林地的气汞浓度峰值出现在植物枝叶密集分布层上部的一定范围内；夜间近地面气汞浓度却表现为近地面0cm,50cm层次低于100cm以上层次的气汞浓度；降雨可降低气汞浓度，但不改变近地面气汞的垂直分布特性。

VERTICAL DISTRIBUTION OF MERCURY IN THE AIR CLOSE TO THE EARTH SURFACE

Vertical distribution of air-Hg above vegetable gardens,farmland,orchards and woodland was studieds with the gold-pipe air-Hg accumulation method.Air-Hg was determined at 0,50,100 and 150 cm above the ground,and its concentration over the vegetable garden was found to be the highest at the 50-cm layer,significantly higher than that at the 0-cm layer.Over the rapeseed field,fruit tree orchard and woodland,the highest concentration of air-Hg appeared somewhere in the canopy of the plants.During the night,the mean concentration of air-Hg was lower at the 0-cm and 50-cm layers than at the 100-cm and 150-cm layers.Rainfall reduced air-Hg concentration,but brought about no change in the distribution pattern of air-Hg.