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| Titel |
Importance of long-term monitoring for detecting environmental change: lessons from a lowland river in south east England |
| VerfasserIn |
T. P. Burt, N. J. K. Howden, F. Worrall, M. J. Whelan |
| 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 ; 5, no. 6 ; Nr. 5, no. 6 (2008-11-11), S.1529-1535 |
| Datensatznummer |
250002920
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| Publikation (Nr.) |
 copernicus.org/bg-5-1529-2008.pdf |
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| Zusammenfassung |
| Rising nitrate concentrations in rivers and groundwater in regions with
intensive agriculture have been of concern for several decades. Long records
of nitrate concentration are rare; in the UK, few pre-date 1974. Records
from the River Stour from 1937 are analysed using moving-windows to explore
the effects of window width on trend detection and process inference.
Nitrate concentrations rose sharply from the late 1950s in response to
widespread ploughing of grassland, but have fallen since the early 1980s,
suggesting that widespread nitrogen control measures, which were introduced
after the start of the downward trend, may not be the principal driver for
recent change. Short windows (5 years) are too noisy; longer windows (10, 15
and 30 years) identify signals (i.e. trends) more reliably. Since system
response times can be of the order of 20–30 years, management decisions made
on shorter data sets (even up to 15 years) could be misleading. |
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