江苏句容小流域NH_3和NO_2干沉积数值模拟

Numerical Simulation for Dry Deposition of Ammonia and Nitrogen Dioxide in a Small Watershed in Jurong County of Jiangsu Province

为了进一步揭示江苏句容小流域NH3和NO2干沉积规律,本文利用当地自动气象站及L波段雷达探空资料和地面气体浓度实测资料,采用气体干沉积阻力模型,并考虑下垫面排放对NH3干沉积的补偿作用,对句容小流域NH3和NO2的干沉积速率、干沉积通量及其影响因子进行数值模拟分析。结果表明:随着稳定度、太阳辐射强度、季节和下垫面的改变,NH3和NO2的干沉积速率均有着较为明显的变化,表面阻力是影响气体干沉积速率变化的主要因子。考虑了下垫面对NH3干沉积的补偿作用后发现,下垫面越富饶的地方,其影响越显著。最后对句容小流域NH3和NO2的干沉积通量进行了估算,发现句容约4556.02hm2的小流域,NH3干沉积通量的月变化范围为13.37～66.29kg·d-1,NO2干沉积通量的月变化范围为21.43～98.92kg·d-1。

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 NH3and 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