中国大陆市域人类活动净氮输入量(NANI)评估

基于NANI模型, 采用中国大陆358个地区级市行政单元的统计数据和本土参数, 核算中国大陆市域尺度的人类活动净氮输入量(NANI)。结果表明: 2010年中国大陆地区NANI总量达到45.15 Tg, 折合单位面积输入强度为4716 kg/km², 是全球平均水平的3倍; 在氮源结构上, 氮肥施用是最大的输入源, 占输入总量的65.0%, 其他依次为食品/饲料净输入(21.4%)、大气沉降(7.3%)和作物固氮(6.5%); 在空间分布上, 市域单元的NANI分布呈现明显区域化特征, 耕地或人口集中的地区NANI强度偏高; 与省域尺度数据对比发现, 市域数据在识别重点控制区域上具有明显优势, 市域尺度数据能够以更小的区域控制面积实现更大的氮源输入控制量。

Evaluating City-Scale Net Anthropogenic Nitrogen Input (NANI) in Mainland China

Based on NANI calculator, statistic data and parameter from 358 cities of China (Hong Kong, Macao and Taiwan are not included) are applied to assess net anthropogenic nitrogen input (NANI) at China’s city scale. On average, NANI of Mainland China has reached to 45.15 Tg in 2010, and on a per area basis the value is 4716 kg/km², which is 3 times than world average level. Nitrogen fertilizer input dominates NANI budget items, which accounts for 65.0% of the total, net food and feed input (21.4%), oxide N deposition (7.3%) and crop fixation (6.5%) follow. On geographical basis, NANI of the 358 cities has an obvious characteristic of regionalization, and high value areas appear in cropland and population concentrated places. Compared to province scale data, data on city scale is more effective to assist in discerning key regions, which is able to control more nitrogen input with smaller control area.