 |
Long-Term Climate Variability in AustraliaVariation in Australian Climate Long-Term Global Climate Variations Long-Term Temperature Variations in Australia Long-Term Rainfall Variations in Australia Other Climate Variations in Australia Long-Term Rainfall Variations in AustraliaPaleoclimate records
indicate that Australia's rainfall has been highly variable for many
thousands of years. This is also supported by the fact that many native
plants and animals have evolved to cope with extended periods of drought.
The number of heavy rainfall events has also increased over some areas of the continent. However, a decreasing trend in winter rainfall has been observed over southwestern Australia in the last 50 years. Not only is Australian rainfall highly variable with time, but its fluctuations also exhibit high spatial variability. This means that, whilst some regions might be unusually wet, at the same time, other parts of the country might be much drier than normal. This spatial variability is evident at both short and long time-scales. Maps of decadal mean rainfall also indicate that some decades are very wet whilst others are much drier than the long-term average. For example, the 1970s are noted for being a wet decade due to several very wet years during this time, whereas the 1930s were a relatively dry decade for much of Australia. Decadal mean rainfall departures from the long-term mean |
|
|
Because
of the large year-to-year changes it is hard to detect any long-term
trends in Australian rainfall. However, some weak trends in rainfall
have been identified. The percentage area of Australia experiencing
extreme wet conditions has increased slightly this century while the
area of extreme dryness has reduced. 