Influence of recent climate on sedimentation in Burrinjuck Reservoir

Abstract

Rainfall, runoff and peak discharge data were used to attmept to explain a declining sedimentation rate in the Burrinjuck Reservoir. A statistically significant increase in rainfall was observed for the period after 1948 compared to the pre-1948 period. Runoff and peak discharge data did not indicate any significant increase in mean. The behaviour of the drainage basin with regard to wetness and potential vegetation was simulated using a simple water balance model and the computer program GROWEST. The drainage basins were slightly wetter in the latter period and a significant increase in growth index was observed, but the increase was not statistically significant. The observed decreased rate of sedimentation in the reservoir since 1948 is attributed to a relatively wet drainage basin in which erosion of the land surface was unchanged but in which tributary channels have become progressively less important sources of sediment. (Authors) Show more