| 摘要: |
| 根据1997–1998年长江和长江口河水和雨水的现场调查、历史资料以及相关文献,定量分析长江流域无机氮的主要来源和输送通量。估算表明,降水无机氮、农业非点源氮(化肥和土壤流失的氮)和点源污水氮的输入分别占长江口无机氮输出通量的62.3%、18.5%和14.4%。氮的降水输入是长江口高含量无机氮的主要来源,进入长江的降水氮仅仅大约占长江流域全部降水氮的36.8%。降水氮主要受控于化肥气态损失、化石燃料燃烧及动植物过程中释放的物质等。实际上,化肥N的气态损失和农业非点源流失大约占长江流域年化肥N使用量的60%,这是控制长江口高含量无机氮的关键因素。 |
| 关键词: 降水 化肥 无机氮 控制因素 长江和长江口 |
| DOI： |
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| 基金项目:中国科学院“九五”重点资助项目KZ952-S1-421号;国家自然科学基金资助项目49876020号;国家专项资助项目SX(97)-11-4号 |
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| THE DOMINANT CONTROLLING FACTORS OF HIGH CONTENT INORGANIC N IN THE CHANGJIANG RIVER AND ITS MOUTH |
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SHEN Zhi-Liang, LIU Qun, ZHANG Shu-Mei, MIAO Hui, ZHANG Ping
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Institute of Oceanology, The Chinese Academy of Sciences, Qingdao, 266071
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| Abstract: |
| Based upon the site investigations of river and rain waters in 1997–1998 in the Changjiang River and its mouth, together with historical data including those in the literature, the main sources and transport fluxes of inorganic N in the Changjiang River catchment were quantitatively estimated. The results show that the inorganic N coming from precipitation, agriculture non-point sources (lost from fertilizer and soil) and point sources sewages discharged were about 62.3%, 18.5% and 14.4% of the export flux of inorganic N in the Changjiang River mouth, respectively. The N from precipitation was the main source of the high content inorganic N in the Changjiang River mouth and the precipitation N entering the Changjiang River was only 36.8% of total precipitation N in the Changjiang River catchment. The N in precipitation was mainly controlled by the fertilizer losses, the combustion of fossil fuels and the released substances from animals and plants processes and so on. In fact, about 60% of consumption of annual fertilizer N were lost from gaseousness and agriculture non-point sources, this is a key factor to control the high content inorganic N in the Changjiang River mouth. |
| Key words: Precipitation, Fertilizer, Inorganic nitrogen, Control factors, The Changjiang River and its mouth |
