THERE has been no general decline in rainfall in Australia due to global warming. But it is possible that the Murray Darling Basin, once regarded as the food bowl of Australia, will get even drier.
When farmers say that the region has never been as dry in their lifetime they are correct. However, the data clearly show that over south eastern Australia the first half of the 20th century was much drier than the second half and the recent ‘drought’ is a return to the conditions of the early 20th century. Also, the recent dry period is not yet as dry as the period from about 1935 through 1945.
The Bureau of Meteorology (BOM) have taken the station annual rainfall since 1900 and created maps of annual rainfall. They have then calculated the average annual rainfall within various regions, including the Murray Darling Basin region. At the website the BOM also have this map which shows the annual departure from the average (anomaly) together with the 11-year average plotted on the 6th year of the averaging period.
The data are available at:
Click on the graph for a better larger view.