摘要
长江源区作为亚洲第一长河的发源地,探究其氮沉降特征,对于保护我国水源地安全具有十分重要的意义.本文在野外采样、数理分析的基础上,利用氮源分析及后向轨迹模型判断氮沉降的环境意义.结果表明:(1)2016年4月-2018年7月,NO_(2)^(-)-N、NO_(3)^(-)-N、NH_(4)^(+)-N的平均浓度分别为1.01 mg/L、2.45 mg/L、1.30 mg/L;NO_(2)^(-)-N、NO_(3)^(-)-N、NH_(4)^(+)-N的平均沉降量分别为0.02 kg/hm^(2)、0.09 kg/hm^(2)、0.30 kg/hm^(2).曲麻莱氮浓度占源区比重最高,沱沱河次之,直门达最小,且春、夏季氮沉降量高于秋、冬季.(2)氮沉降浓度与降水量之间呈对数函数关系,沉降量与降水量之间呈正向幂函数关系;NO_(2)^(-)-N、NO_(3)^(-)-N沉降量与温度呈负相关性,NH_(4)^(+)-N与温度呈正相关性.(3)长江源区夏季NH_(4)^(+)-N沉降增加主要源于牧民放牧,冬季NO_(x)^(-)-N沉降增加主要源于煤炭燃烧,且污染物传递还受到西风环流及局地环流影响,境外来源更多集中在西亚地区.
As the source of the longest river in Asia,the source region of the Yangtze River is great significance to explore its nitrogen deposition characteristics for protecting the safety of water sources in China.The result shows:(1)From April 2016 to July 2018,the average concentrations of NO_(2)^(-)-N、NO_(3)^(-)-N and NH_(4)^(+)-N were 1.01 mg/L,2.45 mg/L and 1.30 mg/L respectively,the average deposition of NO_(2)^(-)-N、NO_(3)^(-)-N and NH_(4)^(+)-N were 0.02 kg/hm^(2)、0.09 kg/hm^(2)、0.30 kg/hm^(2).Qumalai had the highest proportion to the overall nitrogen deposition concentration in the source region of the Yangtze River,followed by the Tuotuo River,Zhimenda was the smallest,and the nitrogen deposition in spring and summer was higher than that in autumn and winter.(2)There was a logarithmic function relationship between nitrogen concentration and precipitation,and a positive power function relationship between deposition and precipitation;NO_(2)^(-)-N and NO_(3)^(-)-N deposition were negatively correlated with temperature,and NH_(4)^(+)-N was positively correlated with temperature.(3)The increase in NH_(4)^(+)-N deposition in the source region of the Yangtze River in summer is mainly due to grazing by herdsmen,and the increase in NO_(x)^(-)-N deposition in winter is mainly due to coal combustion,and the transmission of pollutants is also affected by westerly circulation and local circulation,and overseas sources are more concentrated in West Asia.
作者
赵越
李宗省
李中平
张百娟
崔乔
Zhao Yue;Li Zongxing;Li Zhongping;Zhang Baijuan;Cui Qiao(Observation and Research Station of Eco-Hydrology and National Park by Stable Isotope Tracing in Alpine Region/Key Laboratory of Ecohydrology of Inland River Basin/Ecological Environment Research Center of Qilian Mountain,Gansu Province,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;Oil and Gas Research Center,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2023年第3期1179-1194,共16页
Earth Science
基金
国家自然科学基金项目(No.42077187)
第二次青藏高原综合科学考察研究项目专题(No.2019QZKK0405)
中国科学院青年交叉团队项目(No.JCTD-2022-18)
中国科学院“西部之光”交叉团队项目-重点实验室合作研究专项
国家重点研发计划项目专题(No.2020YFA0607702)
甘肃省创新群体项目(No.20JR10RA038)。
关键词
长江源区
氮沉降
大气降水
大气化学
生态学
the source region of Yangtze River
nitrogen deposition
atmospheric precipitation
atmospheric chemistry
ecology
