 |
| Titel |
How does climate change affect mesoscale catchments in Switzerland? – a framework for a comprehensive assessment |
| VerfasserIn |
N. Köplin, D. Viviroli, B. Schädler, R. Weingartner |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7340
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrologic Modelling for the Assessment of Ecosystem Services and Landscape Functions ; Nr. 27 (2010-09-28), S.111-119 |
| Datensatznummer |
250016347
|
| Publikation (Nr.) |
 copernicus.org/adgeo-27-111-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
Within the framework of this study we identify mesoscale catchments in
Switzerland that exhibit sensitivity towards a change in climate with a focus
on alterations of the water balance and peak flow conditions. For this study,
the hydrological modelling system PREVAH is used, which is a semi-distributed
and conceptual yet process-oriented model forced with hourly meteorological
input on basis of a spatial resolution of 500×500 m2. We
calibrate the model where measured discharge records are available and
transfer the calibrated model parameters to ungauged catchments through
regionalisation, to arrive at a comprehensive set of model parameters for the
entire area of Switzerland. To assess future changes, we apply an extensive
set of 16 Regional Climate Models (RCMs) to the catchments. The RCM data are
downscaled to a dense network of meteorological stations for the period from
2021 to 2050 using the Delta Change Approach. This downscaling method
incorporates a bias correction of the RCM output and provides change rates
and values for precipitation and temperature.
In the present paper we describe the application of a calibration and
regionalisation procedure developed previously for Northern Alpine catchments
to Southern catchments. The necessity to differentiate between a Northern and
a Southern Alpine region, with their distinct climatologic and
physiogeographic features, has proved true as the calibrated parameter sets
show systematic differences between those regions, e.g. for the runoff
forming parameters percolation rate (PERC) or storage time for quick runoff
(KOH). For the Southern Alpine area, we calibrated two thirds of the
available catchments, i.e. 23 out of 36, successfully for standard and flood
conditions according to a combined model score of a linear and logarithmic
Nash-Sutcliffe-Efficiency (NSE, NSEln) and a mean annual volumetric
deviation (VDa). The rate of successfully calibrated catchments is
rather small in comparison with the results for the Northern Alpine
catchments, where 140 out of 159 calibrations have been successful, and the
distribution of the Southern catchments is more irregular. However, as the
median NSE and NSEln as well as the range of VDa show an
overall good model fit, a successful regionalisation may be expected. Next
steps are the regionalisation of the Southern Alpine model parameters and the
application of climate scenarios to the complete set of catchments,
i.e. about 200 Swiss mesoscale catchments with an average area of
150 km2. Thus we can identify process-based relationships between climate
sensitivity and catchment characteristics and provide quantitative
information on future water balance and peak flow conditions of Swiss
mesoscale catchments. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|