Streamflow characteristics of northeastern Tasmania: I. regional flood flows

Abstract

Based on streamflow records from thirteen stations, regional equations are developed which enable the estimation of mean annual discharge and various flood flows at ungauged sites along rivers in northeastern Tasmania. The area around Swansea is shown to be hydrologically distinct, at least as far as flood discharges are concerned, and the analysis subsequently focuses on the rest of the region. Despite the wide range of climatic and physiographic conditions there, relationships are highly significant, with drainage area explaining more than 97% of the variation in flood discharge. Rates of change are not only relatively high but increase with flood magnitude, suggesting rapid downstream transmission of flood waters. Network magnitude may be a viable alternative to drainage area as an estimator. Its use has the advantage that the downstream pattern of flow addition can be readily charted for major rivers, as illustrated for the Ringarooma and George.