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| Titel |
Long-term low-frequency or short-term high-frequency monitoring: are both necessary? |
| VerfasserIn |
Sarah Halliday, Andrew J. Wade, Colin Neal, Brian Reynolds, Dave Norris, Richard Skeffington |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250045678
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| Zusammenfassung |
| This paper describes the patterns observed in a high-frequency (7-hourly) streamwater
chemistry data set obtained for the Plynlimon Catchment, Wales from 2007-2009. Plynlimon
is an upland site underlain by lower Palaeozoic mudstones, greywackes and sandstones
that are overlain by thin acidic soils comprised mainly of stagnopodzols and peats.
Vegetation cover is dominated by acid grassland (Nardus-Festuca) and heath land with
plantation forestry in the lower parts of the catchment (mainly Sitka spruce Picea
sitchensis). The site has a long history of environmental monitoring which started in
earnest in the early 1980s and continues to the present day to look at the issues
of evapotranspiration from coniferous forest and the impacts of clear felling and
acid deposition on soil and streamwater quality. The new dataset is explored using
time-series analysis and this talk will focus on a sub-set of determinands including pH,
aluminium, chloride, nitrate, calcium, sulphate, silicon, DOC, iron and conductivity.
The results are compared with a longer-term (1983-2010) hydrochemical dataset
from the same study area which was sampled at lower frequency (weekly). This
comparison provides an opportunity to assess the value and information content of both
long-term, low frequency and short-term, high-frequency datasets. The results will be
discussed in terms of the catchment hydrological and hydrochemical processes
operating at different spatial and temporal scales. The discussion will also focus on the
information content of high-frequency water quality data versus the cost of collection. |
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