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| Titel |
Smooth regional estimation of low-flow indices: physiographical space based interpolation and top-kriging |
| VerfasserIn |
S. Castiglioni, A. Castellarin, A. Montanari, J. O. Skøien, G. Laaha, G. Blöschl |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 15, no. 3 ; Nr. 15, no. 3 (2011-03-04), S.715-727 |
| Datensatznummer |
250012676
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| Publikation (Nr.) |
 copernicus.org/hess-15-715-2011.pdf |
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| Zusammenfassung |
| Recent studies highlight that spatial interpolation techniques of point data
can be effectively applied to the problem of regionalization of hydrometric
information. This study compares two innovative interpolation techniques for
the prediction of low-flows in ungauged basins. The first one, named
Physiographical-Space Based Interpolation (PSBI), performs the spatial
interpolation of the desired streamflow index (e.g., annual streamflow,
low-flow index, flood quantile, etc.) in the space of catchment descriptors.
The second technique, named Topological kriging or Top-kriging, predicts the
variable of interest along river networks taking both the area and nested
nature of catchments into account. PSBI and Top-kriging are applied for the
regionalization of Q355 (i.e., a low-flow index that indicates the
streamflow that is equalled or exceeded 355 days in a year, on average) over
a broad geographical region in central Italy, which contains 51 gauged
catchments. The two techniques are cross-validated through a leave-one-out
procedure at all available gauges and applied to a subregion to produce a
continuous estimation of Q355 along the river network extracted from a
90m elevation model. The results of the study show that Top-kriging and PSBI
present complementary features. Top-kriging outperforms PSBI at larger river
branches while PSBI outperforms Top-kriging for headwater catchments.
Overall, they have comparable performances (Nash-Sutcliffe efficiencies in
cross-validation of 0.89 and 0.83, respectively). Both techniques provide
plausible and accurate predictions of Q355 in ungauged basins and
represent promising opportunities for regionalization of low-flows. |
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