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| Titel |
Spatially smooth estimation of low-flows: Canonical-Kriging and Top-Kriging |
| VerfasserIn |
Attilio Castellarin, Simone Castiglioni, Alberto Montanari, Jon O. Skøien, Gregor Laaha, Günter Blöschl |
| 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 |
250054380
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| Zusammenfassung |
| Recent studies highlight that geostatistical interpolation, which has been originally developed
for the spatial interpolation of point data, can be effectively applied to the problem of
regionalization of hydrometric information. This study compares two innovative and
kriging-based approaches for the prediction of low-flows in ungauged basins. The first one,
named Canonical-Kriging or Physiographic-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. Canonical-Kriging and Top-kriging are applied for the regionalization
of Q355 (i.e., 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. Both 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 DEM. The results of the study show
that Top-kriging and Canonical-Kriging present complementary features and 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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