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大气氮沉降作为人类面临的重大问题,越来越受到人们的重视,而大气湿沉降氮更是研究热点。本文以吉林省中部生态地区为例,通过研究该农区湿沉降氮的总体特征和输入氮相关参数(p H、总氮、铵氮、硝氮),明确了该区域大气湿沉降氮年际发生规律和季节分异特征,掌握了我省中部农区农田生态系统湿沉降氮的负荷情况,得出以下结论:(1)降雨年际间变异较大,极端年出现的频次高于平均年的频次,且降水量变化具有明显的季节性,最大降雨量集中6~9月,占全年降水的70%左右;(2)降雨p H值变化幅度较小,平均值为6.91。降雨氮浓度变异系数较大,且总氮浓度超过入湖库水浓度(2 mg L-1)2倍多,而铵氮浓度介于地表水III类与IV类之间,是地下水质铵氮标准的4倍;(3)年均湿沉降总氮量为18.3 kg hm-2,无机氮的沉降量为10.3 kg hm-2,对总氮贡献率为57%;(4)氮沉降量与降雨量和氮浓度呈显著或极显著正相关关系,对于湿沉降总氮来说,雨量的相关性好于浓度的相关性,而对于湿沉降的无机氮而言,浓度的相关性好于雨量的相关性。
Atmospheric nitrogen deposition as a major issue facing mankind, more and more people’s attention, and atmospheric wet deposition of nitrogen is a research hotspot. Taking the ecological areas in central Jilin Province as an example, this paper studied the general characteristics of wet depositional nitrogen and the related parameters of input nitrogen (p H, total nitrogen, ammonium nitrogen and nitrate nitrogen) Regularity and seasonality were observed, and the load of wet depositional nitrogen in farmland ecosystem in the central part of our province was grasped. The conclusions are as follows: (1) The variability of rainfall in the interannual period is larger and the frequency of extreme years is higher than that of the average year The frequency of precipitation is obviously seasonal. The maximum rainfall is concentrated from June to September, accounting for about 70% of the annual precipitation. (2) The variation of precipitation p H is small, with an average of 6.91. The coefficient of variation of rainfall nitrogen concentration was larger and the total nitrogen concentration was more than 2 times that of the lake water concentration (2 mg L-1). However, the ammonium nitrogen concentration was between surface water types III and IV, Standard 4 times; (3) The average annual wet deposition of total nitrogen is 18.3 kg hm-2, the amount of inorganic nitrogen is 10.3 kg hm-2, the contribution rate to total nitrogen is 57%; (4) There was a significant or very significant positive correlation between rainfall and nitrogen concentration. For wet deposition of total nitrogen, the correlation of rainfall was better than that of concentration, while for wet deposition of inorganic nitrogen, the correlation between concentration and rainfall was better than that of rainfall Relevance.