Figure 3: Example outputs of the metrics from the two key locations used in the development of the metrics. Barossa Valley gorge uses data from the Yaldara gauging station, Lower Flaxman Valley uses data from the Penrice gauging station. Red – observed data, blue – modelled no dams data, green – current modelled data.

Metric correlation

To ensure that there was no excessive correlation between metrics, a Pearson’s correlation was undertaken between the six metrics. While a degree of correlation between the metrics was expected driven by climatic drivers (e.g. wet/dry years), the objective was to produce metrics that were no more that 75% correlated. The results of the correlation assessment (Table 4) showed that the highest correlation was 70.4% between medium and high flow days. This was followed by flowing days and low flow days over the low flow season with a correlation of 67.9%. The remaining metrics were well below the level of concern.
Table 4: Correlation assessment between the six identified metrics using Pearson correlation.