Abstract: Based on the observation data of the automatic weather station,the L-band radar sent,the gas concentration,the dry deposition rate,the dry deposition flux and the influencing factors of dry deposition of NH3 and NO2 in a small watershed in Jurong County of Jiangsu Province were calculated and analyzed,considered the compensation role of the dry deposition of NH3 from the surface emission. The results showed that with the change of stability,solar radiation intensity,season and surface,the dry deposition rate of ammonia and nitrogen dioxide obviously changed. The apparent resistance was the main factor affected the gas dry deposition rate. In consideration of the role of the surface compensation for the dry deposition of NH3,the more fertiler the surface compensation was,the more significant the impacts on the dry deposition of NH3. Finally,the dry deposition rate and the dry deposition flux of NH3 and NO2 in a small watershed in Jurong County were estimated. The monthly change of the dry deposition flux of NH3 was in the range of 13.37-66.29kg·day-1,while the monthly change of the dry deposition flux of NO2 was in the range of 21.43 -98.92kg·day-1.

Key words: Ammonia, Ammonia, Nitrogen dioxide, Dry deposition model, Compensation