Regional Variations in Flow-Duration Curves for Rivers in British Columbia, Canada

Abstract

The estimation of flow quantiles and the regionalization of hydrologic characteristics are two major foci of current hydrologic research. A flow-duration curve represents the annual flow-frequency characteristics of rivers by depicting the cumula tive frequencies for average ranked flows in a river. Generally the process requires the empirical estimation of the mean flow at each of 365 ranks. A model requiring only five parameters is developed by combining the principles of order statistics and traditional flow-frequency analyses and is applied to flow-duration curves for rivers in the province of British Columbia, Canada. Results from the model may be interpreted both statis tically and physically and allow the identification of hydrologically similar regions. Streamflows in British Columbia are generated from a number of distinct physical processes operating in highly diverse environments. The mixture of the streamflowgenerating processes requires that the statistical model be capable of encompassing the different flow-frequency regimes. Identification of hydrologic regions also depends on the inclusion of these generating processes. The model presented incorporates the physical generating processes of streamflow in both the statistical representation of flow-duration curves and their interpretation. Similarly, the spatial model presents hydrologic regions that correspond to the known physical environment. [

Flow Regime Classification and Hydrological Characterization: A Case Study of Ethiopian Rivers

“…A number of studies presented different relationships of catchment descriptors with regional models of FDCs for various geographical areas of the world [21,[52][53][54][55][56][57][58][59]. Similarly, the linear relationships of catchment descriptors and FDC presented in Table 4 can serve as the basis for the estimation of FDC for ungauged catchments and also to characterize the flow regimes of ungauged catchments of the country.…”

An elusive search for regional flood frequency estimates in the River Nile basin

“…The relative performance of the clustering can be improved by application of an ensemble of clustering algorithms (Ramachandra Rao and Srinivas, 2005). Hierarchical Clustering (HC) is one of the widely used methods in hydrology (LeBoutillier and Waylen, 1993;Mosley, 1981) and consists of four different cluster algorithms. Once the homogeneous regions are delineated they can be tested for homogeneity (Wiltshire, 1986).…”

“…Regional flood frequency analysis using physical catchment characteristics have been shown to produce reliable results if the physical catchment characteristics, chosen objectively, influence the spatial variability of hydrological characteristics (Kjeldsen et al, 2001;Kachroo et al, 2000;Parida et al, 1998;Zrinji and Burn, 1996;Kim and Hawkins, 1993;LeBoutillier and Waylen, 1993;Cunnane, 1988;Wiltshire, 1986;Acreman and Sinclair, 1986;Mosley, 1981). One of the key steps in such analysis is the delineation of the study area into homogeneous regions.…”

Regional flow duration curves for ungauged sites in Sicily

“…Often these studies regard large catchments with perennial streamflows, as Canada (Leboutillier and Waylen, 1993), India (Singh et al, 2001), Italy (Castellarin et al, 2007Castellarin et al, 2004;Franchini and Suppo, 1996;Iacobellis, 2008;Ganora et al, 2009), Greece (Niadas, 2005), Taiwan (Yu et al, 2002), Philippines (Quimpo et al, 1983), South Africa (Smakhtin et al, 1997) and United States (Fennessey and Vogel, 1990). It is important to point out that analysis of FDC for small catchments with ephemeral streamflows, as in Portugal (Croker et al, 2003) are less frequent than studies for perennial streamflows.…”