近15年北部湾西部近岸大气湿沉降中无机氮的研究

Inorganic Nitrogen of the Atmospheric Wet Deposition in the Western Coast of the Beibu Gulf in Recent 15 Years

本文利用2000~2014年北部湾西部近岸的两个城市（河内和太平）的湿沉降无机氮（NO_3^--N和NH_4~＋-N）数据,分析了湿沉降无机氮的浓度和通量的长期变化规律,并结合北部湾海水中的无机氮浓度讨论了湿沉降对海水生态系统的影响。结果表明,近15年来河内和太平两个区湿沉降无机氮的月平均浓度总体上在5~9月较低,在10月至次年4月较高;这两个区域湿沉降无机氮的年平均浓度总体呈上升趋势。估算结果表明的湿沉降给北部湾带来的NO_3^--N和NH_4~＋-N的量分别为46448.6和83220.5 t/a。湿沉降可能对于近年来北部湾海水中NH_4~＋-N的相对含量升高及N过剩有重要影响。

In this study,data of the inorganic nitrogen（NO3^--N and NH4^＋-N） in the wet deposition of two cities of Vietnam（Hanoi and Hoa Binh） located in the western coast of the Beibu Gulf during the period from 2000 to 2014 were utilized to study the long-term variation regularities of concentrations and fluxes of the inorganic nitrogen in the atmospheric wet deposition and then to discuss the influence of the eco-system of sea water by the atmospheric wet deposition with the combination of the concentration of inorganic nitrogen in sea water of the Beibu Gulf.The results show that the monthly mean concentrations of the inorganic nitrogen in wet deposition of the above two cities were generally low during the period from May to October,but were relatively high during the period from November to the next April.In addition,their annual mean concentrations are generally increased from 2000 to 2014.The estimated fluxes of NO3^--N and NH4^＋-N in the wet deposition in the Beibu Gulf are 46448.6 and 83220.5 t/a,respectively.Therefore,it is suggested that the wet deposition may strongly influenced the increase of the relative concentrations of NH4^＋-N and the excess of nitrogen in the sea water of the Beibu Gulf.