Author(s): U. Piock-Ellena; R. Merz; G. Bloschl; D. Gutknecht

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Keywords: Regionalisation; Seasonality of hydrological data; Cluster analysis; Catchment similarity; Homogeneous regions

Abstract: In this paper an approach towards flood regionalisation is presented, in which homogeneous regions are defined based on seasonality measures of floods and of the runoff regime. The rationale behind this approach is that we believe that similarities in the seasonality of hydrologic variables are often a consequence of similarities in the underlying hydrological and meteorological processes and hence are a rational basis for identifying homogeneous, hydrologically similar flood frequency regions. We use cluster analyses to identify eight regions in Austria. These are one glacier melt dominated region, two regions dominated by Alpine snow melt, one region dominated by orographic and/or synoptic rainfall, one region dominated by convective storms, and three regions dominated by a combination of rainfall and snow melt in winter and spring. The regions found here are clearly more appropriate for flood regionalisations than a catchment grouping based on the coefficient of variation and the skewness of the flood record sample alone. The regions are consistent with expert judgment of the important flood processes but have been found by a more objective method.

DOI:

Year: 1999