Indicator: A-02 Rainfall trends - annual mean rainfall

Data

Annual Rainfall for Australia

Annual Rainfall for Australia

Source: Bureau of Meteorology 2005, Annual all-Australian mean rainfall.

Trend in Annual Total Rainfall: 1900-2004 (mm/10yrs)

 1900-2004 (mm/10yrs)

Source: Bureau of Meteorology, Australia

Trends in annual total rainfall for three time periods, 1900-2005, 1950-2005 and 1970-2005

Trends in annual total rainfall for three time periods, 1900-2005, 1950-2005 and 1970-2005

Source: Bureau of Meteorology, 2006

What the data mean

Spatially, regional rainfall trends from 1900 to 2004 show both increases and decreases. Large increases (greater than 20 mm per ten years) since 1950, intensifying since 1970, have been observed in north-west Australia. Decreases since 1950, intensifying since 1970, have occurred in all the eastern states, South Australia and much of the Northern Territory.

The rainfall graph shows an increase in annual rainfall averaged across the continent over the reporting period 1900 to 2004. The increase from the mid 1970s is more pronounced. This is interesting given that the area affected by decreased rainfall seems to be greater than the area affected by increased rainfall. It also contrasts with the data relating to the Southern Oscillation Index, which shows that there have been more frequent and severe El Nino events (drier periods) since the mid 1970s.

Data Limitations

Nil

Issues for which this is an indicator and why

Atmosphere - Climate variability and change - Weather 

Australia is the driest inhabited continent on earth. Its interior has one of the lowest rainfalls in the world and about three-quarters of the land is arid or semi-arid. Rainfall trends are important from an environmental and an economic perspective. For thousands of years, Australia has experienced strong year-to-year variations in rainfall. These natural variations and any more extreme variations or changes in the normal scope of variation that may result from anthropogenic climate change that may result from anthropogenic climate change are important indicators for the condition of the atmosphere.

Other indicators for this issue:

Land - Contributions and pressures between the land and the atmosphere - Climate 

Australia is the driest inhabited continent on earth. Its interior has one of the lowest rainfalls in the world and about three-quarters of the land is arid or semi-arid. Rainfall trends are important from an environmental and an economic perspective. For thousands of years, Australia has experienced strong year-to-year variations in rainfall. These natural variations and any more extreme variations or changes in the normal scope of variation that may result from anthropogenic climate change are important indicators for the pressure of this change on the land.

Other indicators for this issue:

Inland Waters - Catchment scale influences - Influence of climate variability and change 

Australia is the driest inhabited continent on earth. Its interior has one of the lowest rainfalls in the world and about three-quarters of the land is arid or semi-arid. Rainfall trends are important from an environmental and an economic perspective. For thousands of years, Australia has experienced strong year-to-year variations in rainfall. These natural variations and any more extreme variations or changes in the normal scope of variation that may result from anthropogenic climate change are important indicators for the pressure of this change on inland waters.

Other indicators for this issue:

Biodiversity - Pressures on biodiversity - Climate variability 

Australia is the driest inhabited continent on earth. Its interior has one of the lowest rainfalls in the world and about three-quarters of the land is arid or semi-arid. Rainfall trends are important from an environmental and an economic perspective. For thousands of years, Australia has experienced strong year-to-year variations in rainfall. These natural variations and any more extreme variations or changes in the normal scope of variation that may result from anthropogenic climate change are important indicators for the pressure of this change on biodiversity.

Other indicators for this issue:

Further Information