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.