Net Anthropogenic Nitrogen Accumulation in the Beijing Metropolitan Region in 2003 to 2007
北京地区2003～2007年人类活动氮累积状况研究

Nitrogen input and accumulation caused by human activities potentially influences the regional environment,especially the water environment.This paper introduces the concept of net anthropogenic nitrogen accumulation,NANA and defines it as the difference between N input and N output caused by human activities,which are estimated from the accumulation in atmospheric N deposition,N fertilizer use,N accumulation of human food and animal feed,N fixation and riverine N accumulation.It is found in the study that ...