杭嘉湖地区大气氮、磷沉降特征研究

通过2013年9月~2014年8月杭嘉湖地区杭州、嘉兴和湖州3个典型站点大气氮、磷沉降数据,探讨了杭嘉湖地区大气氮、磷沉降的污染特征.结果表明,目标地区内大气氮、磷沉降通量水平较高,分别为4950.74~5585.80,65.25~69.72kg/(km2·a);直接降入水域中的氮、磷素分别为6038.4,77.8t,分别相当于农业源的氮、磷入河量的39.6%和5.9%.氮沉降以湿沉降形式为主,磷沉降以干沉降形式为主;氮、磷湿沉降通量主要受降雨量影响,且随降雨量的增加而增加;氮、磷沉降存在时空差异性,大气氮干沉降通量以杭州、嘉兴地区为较高,大气磷干沉降通量以嘉兴地区为最高,大气氮湿沉降通量则以湖州、嘉兴地区为较高,大气磷湿沉降以湖州地区最高;时间尺度上,氮沉降夏秋两季最高,磷沉降以秋冬两季最高.

Atmospheric nitrogen and phosphorous deposition in Hangjiahu area

Available data of atmospheric nitrogen and phosphorous deposition during Sep, 2013 to Aug, 2014, were collected from three typical monitoring stations of Hang-Jia-Hu area, which are located at Hangzhou, Jiaxing andg Huzhou city respectively. The pollution characteristics of this area were discussed. Annual bulk deposition of nitrogen and phosphorous were significantly high in range of 4950.74~5585.80 and 65.25~69.72kg/(km2·a); Atmospheric deposition of nitrogen, phosphorus into the water were 6038.4 and 77.8 tons, respectively, equivalent to 39.6% and 5.9% input amount of nitrogen and phosphorus by agricultural. The principal deposition form for nitrogen was wet deposition, while for and phosphorous, it was dry deposition. Wet deposition of nitrogen and phosphorous were affected by rainfall situation, and usually increased along with the rainfall amount. The spatial ariation characteristics of nitrogen and phosphorous showed that high dry atmospheric deposition of nitrogen (Hangzhou, Jiaxing), high dry atmospheric deposition of phosphorous (Jiaxing), high wet nitrogen deposition (Huzhou, Jiaxing), and high wet phosphorous of Huzhou. On the time scale, nitrogen deposition was much higher in summer and autumn, while phosphorus deposition was much higher in autumn and winter.