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| Titel |
Anthropogenic point-source and non-point-source nitrogen inputs into Huai River basin and their impacts on riverine ammonia–nitrogen flux |
| VerfasserIn |
W. S. Zhang, D. P. Swaney, X. Y. Li, B. Hong, R. W. Howarth, S. H. Ding |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 12, no. 14 ; Nr. 12, no. 14 (2015-07-22), S.4275-4289 |
| Datensatznummer |
250118029
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| Publikation (Nr.) |
 copernicus.org/bg-12-4275-2015.pdf |
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| Zusammenfassung |
| This study provides a new approach to estimate both anthropogenic non-point-source and point-source nitrogen (N) inputs to the landscape, and determines
their impacts on riverine ammonia–nitrogen (AN) flux, providing a foundation
for further exploration of anthropogenic effects on N pollution. Our study
site is Huai River basin of China, a water–shed with one of the highest levels
of N input in the world. Multi-year average (2003–2010) inputs of N to the
watershed are 27 200 ± 1100 kg N km−2 yr−1. Non-point
sources comprised about 98 % of total N input, and only 2 % of inputs
are directly added to the aquatic ecosystem as point sources. Fertilizer
application was the largest non-point source of new N to the Huai River basin
(69 % of net anthropogenic N inputs), followed by atmospheric deposition
(20 %), N fixation in croplands (7 %), and N content of imported food
and feed (2 %). High N inputs showed impacts on riverine AN flux:
fertilizer application, point-source N input, and atmospheric N deposition
were proved as more direct sources to riverine AN flux. Modes of N delivery
and losses associated with biological denitrification in rivers, water
consumption, interception by dams may influence the extent of export of
riverine AN flux from N sources. Our findings highlight the importance of
anthropogenic N inputs from both point sources and non-point sources in
heavily polluted watersheds, and provide some implications for AN prediction
and management. |
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