The effect of climate change on water resources has been an area of
continued research, especially in Australia. Previous studies have
suggested significant trends in rainfall, and these are amplified
causing larger changes in streamflow. However, most of the previous
analysis was based on annual time scales or modelled data and did not
account for changes in land cover, which could interact with changes in
climate. Climate data and streamflow data sourced from 13 fully forested
small catchments (<250 km2) was analysed for trends.
Non-parametric Mann-Kendall trend analysis, generalised additive mixed
modelling and rainfall-runoff modelling were combined for the analysis.
This indicates consistent increases in maximum temperature and varied
decreases in rainfall. Limited to a small number of catchments in south
eastern Australia there were small, but significantly amplified,
decreases in streamflow. In general, overall decreases are much smaller
than predicted in earlier research.