上海地区大气氮湿沉降及其对湿地水环境的影响

Atmospheric nitrogen wet deposition and its effects on wetland water environment of Shanghai area.

根据1998～2003年上海地区雨水中NO3^- -N、NH4^＋ -N浓度,采用单因子评估模式评价了降雨对湿地水环境的影响,并结合降雨量数据,研究了大气湿沉降氮通量.结果表明,上海地区雨水中氮浓度较高,6年雨水平均硝态氮浓度为2.59 mg·L^-1,铵态氮浓度为2.16 mg·L^-1,总无机氮（TIN）浓度4.74 mg·L^-1,远大于水体富营养水中氮浓度阀值（0.2 mg·L^-1）,依据降水中的氮浓度,降水已达到地表水V类、劣V类水平.6年湿沉降氮通量平均值为58.1 kg·hm^-2·yr^-1,其中NO3^- -N占54%.大气氮沉降对湿地水体富营养化影响值得关注.

Based on the observation data of the rainfall and its NO3^- -N and NH4^＋ -N concentrations in Shanghai area from 1998 to 2003, and by the method of single factor evaluation, this paper studied the flux of atmospheric nitrogen wet deposition and its effects on wetland water environment of this area. The results showed that in the six years, the nitrogen content in the rainwater was rather high, with an average concentration of NO3^- -N and NH4^＋ -N being 2.59 mg·L^-1 and 2.16mg·L^-1, respectively, and a total inorganic nitrogen of 4.74mg·L^-1, which exceeded the water eutrophication level （ 0.2mg·L^-1 ）. According to the nitrogen concentration, the rainwater belonged to V and inferior V types of surface water quality. The nitrogen flux by wet deposition in the six years was 58.1 kg ·hm^-2·yr^-1, among which, NO3^- -N accounted for 54%. The effects of atmospheric nitrogen wet deposition on the eutrophication of the wetland water environment should be paid more attention.