 |
| Titel |
Catchment classification based on a comparative analysis of time series of natural tracers |
| VerfasserIn |
Christian Lehr, Gunnar Lischeid, Doerthe Tetzlaff |
| Konferenz |
EGU General Assembly 2014
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250094005
|
| Publikation (Nr.) |
 EGU/EGU2014-9280.pdf |
|
|
|
|
|
| Zusammenfassung |
| Catchments do not only smooth the precipitation signal into the discharge hydrograph, but
transform also chemical signals (e.g. contaminations or nutrients) in a characteristic way.
Under the assumption of an approximately homogeneous input signal of a conservative tracer
in the catchment the transformation of the signal at different locations can be used to infer
hydrological properties of the catchment. For this study comprehensive data on geology,
soils, topography, land use, etc. as well as hydrological knowledge about transit times, mixing
ratio of base flow, etc. is available for the catchment of the river Dee (1849 km2) in Scotland,
UK. The Dee has its origin in the Cairngorm Mountains in Central Scotland and flows
towards the eastern coast of Scotland where it ends in the Northern Sea at Aberdeen.
From the source in the west to the coast in the east there is a distinct decrease in
precipitation and altitude. For one year water quality in the Dee has been sampled
biweekly at 59 sites along the main stem of the river and outflows of a number of
tributaries. A nonlinear variant of Principal Component Analysis (Isometric Feature
Mapping) has been applied on time series of different chemical parameters that were
assumed to be relative conservative and applicable as natural tracers. Here, the
information in the time series was not used to analyse the temporal development
at the different sites, but in a snapshot kind of approach, the spatial expression
of the different solutes at the 26 sampling dates. For all natural tracers the first
component depicted > 89 % of the variance in the series. Subsequently, the spatial
expression of the first component was related to the spatial patterns of the catchment
characteristics. The presented approach allows to characterise a catchment in a spatial
discrete way according to the hydrologically active properties of the catchment on the
landscape scale, which is often the scale of interest for water managing purposes. |
|
|
|
|
|
|