A hydrological regionalization of streams in Victoria, Australia, with implications for stream Ecology

Annual, monthly, low and peak flow data were used to classify and ordinate 138 stream gauges in Victoria. Sixteen hydrological variables were used and low-flow and entire-flow regionalizations were derived. The low-flow regionalization was spatially indistinct and therefore unusable, but the entire-flow regionalization produced five distinctive and spatially significant regions. Least-squares relationships were calculated between mean annual runoff, catchment area and coefficient of variation of annual flows, and the 16 variables. Rivers in the dry western districts of Victoria exhibit high variability of annual, monthly and peak flows, and low specific low flows. The converse is true for rivers in the western highlands of Victoria. Stream regionalizations are a useful tool for stream ecologists, and may be used for generating hypotheses, for detecting representative rivers and for producing baseline stream surveys.