Some Comments on Regionalization in Hydrologic Studies

Abstract

At the jth site, a choice must be made between Yi, a statisticM characteristic of the observed flows, and •i, a regionalized estimate of the characteristic, for use in the model for generating synthetic flows at the jth•site. The regional estimate is obtained from a regression of y on a set of basin characteristics. If Vii/Vii < 2 --O •, then •i instead of Yi is used in the generating model, where •rii and Vii are the variances of •i and Yi, respectively, and o' is a measure of the interstation correlations. This criterion is shown to be independent of the jth basin characteristics. The criterion is a function of the jth basin characteristics if the data at the jth site are not used in developing the regression relation. For an ungaged site, •i may be obtained with variance that depends upon the basin characteristics at the jth ungaged site. (

Regional frequency analysis of extreme precipitation in the eastern Italian Alps and the August 29, 2003 flash flood

“…The concept was continuously developed since, and new approaches were regularly developed by researchers (e.g. Benson, 1962;Matalas and Gilroy, 1968;Vicens et al, 1975;National Environment Research Council (NERC), 1975;Greiss and Wood, 1981;Rossi et al, 1984;Hosking et al, 1985;Lettenmaier et al, 1987;Burn, 1990;Buishand, 1991;Stedinger and Lu, 1995;Hosking and Wallis, 1997;Reed et al, 1999;Sveinsson et al, 2001;Koutsoyiannis, 2004). A common method for pooling summary statistics from different sites is the index variable procedure, referred to also as the ''index flood'' from early studies (Dalrymple, 1960) that used flood data when implementing the procedure.…”

Regional hydrologic analysis: Ordinary and generalized least squares revisited

“…Relationships between flow statistics and geomorphic, geologic, climatic, and topographic parameters have been formulated in many regions for low flows [Thomas and Benson, 1970;Thomas and Cervione, 1970;Riggs, 1972;Vogel and Kroll, 1992] and for flood flows [Benson, 1962;Matalas and Gilroy, 1968;Thomas and Benson, 1970; This paper is structured as follows. Section 2 presents the regional regression problem.…”

An Amplification Model for the Regional Estimation of Extreme Rainfall within Orographic Areas in Campania Region (Italy)

“…The probabilistic model is coupled with a three level hierarchical procedure for the regional estimation of the parameters. The regional model is a simple model of homogeneous region at each level [8].…”

“…A common solution to the problem is to split the region into homogeneous sub-regions in order to apply regression relationships with at site descriptors of topography within the homogeneous regions [3,[8][9][10]. A more sophisticated approach consists in coupling a regression model with a spatial, nonparametric model of the residuals [4,6,11].…”