长江三角洲氮收支的估算及其环境影响

根据2002年基本统计数据和相关参数,对长江三角洲经济区氮的收支及人为扰乱了的氮循环对环境的影响进行了估算与分析.结果表明,2002年长江三角洲经济区输入的氮量达2.94 Yg·a-1(1Tg=1012g),单位国土面积接收的氮量(291 kg·hm-2·a-1)4.5倍于全国平均水平,陆地氮通量(224 kg·hm-2·a-1)不仅高于全国和长江流域,也远远高于北大西洋沿岸的欧美国家.大部分输入氮源与农业有关.2002年该经济区支出氮量1.66～1.95 Tg·a-1,盈余氮0.99～1.28 Tg·a-1.可以预测,长江三角洲经济区将面临氮过量引发的严重环境问题.

Nitrogen budgets of the Yangtse delta region and their effect on the environment

This study estimated the nitrogen budget of the Yangtse River delta region and evaluated the effect of the human-altered nitrogen cycle on the environment.The total nitrogen input to the region was 2.94 Tg in 2002,and the average nitrogen input per unit area was 291 kg·hm^-2·a^-1,4.5 times the national average.The nitrogen flux on land was 224 kg·hm^-2·a^-1,not only far higher than that of the Euramerican countries around the North Atlantic Ocean,but also higher than that of the whole Yangtse River region and of the rest of China.Most of the nitrogen input was associated with agriculture.Total nitrogen output from the region was 1.661.95 Tg·a^-1,resulting in a nitrogen surplus of 0.991.28 Tg·a^-1.The Yangtse delta region,therefore,will face a series of serious environmental problems caused by this nitrogen overflow.