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| Titel |
Different sensitivity of streamflow components to spatial variability in complex topography |
| VerfasserIn |
Silvia Simoni, Amilcare Porporato, Simone Padoan, Marc Parlange |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250043568
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| Zusammenfassung |
| A complex field experiment was conducted in a 20 km2 Alpine catchment to investigate the
impact of spatial variability on stream flow generation. 10 Sensorscope stations were installed
over a wide range of elevations and aspects to capture the spatial variability of different
hydrological forcing parameters including: precipitation, air temperature, relative humidity,
wind speed and direction, solar radiation and skin temperature, among other soil-atmosphere
variables. Streamflow at the exit of the catchment was also monitored with high temporal
resolution.
Data analysis revealed different degrees of sensitivity to spatial variability. Snow and ice melt
streamflow components, showing a diurnal trend of different amplitudes and duration
declining to ward the summer, were practically unaffected by the spatial variability in their
forcing, as air diurnal temperature was adequately described  regardless of the complex
topography. On the contrary, rainfall-run off resulted to be dominated by the highly random
spatial occurrence of convective rainfall events. Similarly, the long-term seasonal decreasing
trend of the groundwater drainage appeared to be strongly affected by spatial variability in
precipitation and topography.
To complement the data analysis, streamflow was also modeled with two models of different
complexity: a 3D-physically based model (GEOtop) proved to be more suitable for
reproducing rainfall-run off response, whereas a simple lumped degree-day type
of model reproduced the snow melt more accurately than the 3D model. This is
likely due to a lack of information on the initial conditions on snow depth over the
catchment and the fact that the snow melt for this watershed was mainly controlled
by the average daily temperature which did no vary significantly over the study
area. |
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