LAND

In 2000, about 46,500 square kilometres (4.65 million hectares) of agricultural land had a high salinity hazard or were at high risk from shallow watertables. About 11,800 kilometres of streams and lake edges, as well as 1,600 kilometres of rail and 19,900 kilometres of roads were at risk.

ABOUT THIS INDICATOR

MAP reports on three dimensions of the natural landscape: biodiversity, land and inland waters.

Australia's soils are old and shallow and are susceptible to degradation by agricultural activities. Dryland salinity for example, occurs when trees or other deep-rooted vegetation are replaced with vegetation that use less water. This causes the water table to rise bringing natural salts to the surface. These salts, in sufficient quantity, are toxic to most plants and thus can reduce agricultural productivity. Dryland salinity threatens biodiversity, through loss of habitat on land and in water, and also impacts on water resources. The salt contained in rising groundwater levels can damage bitumen and concrete and so affect roads, footpaths, housing, pipelines and other assets. Areas near water are often worst affected because they occupy the lowest parts of the landscape where saline groundwater first reaches the surface.

The effects of dryland salinity are considered an important measure of environmental progress. However, the salinity data presented above for this headline indicator have not been updated since the first release of MAP in 2002, as there is no more recent data available.

SEE ALSO

State and territory spreadsheets
The natural landscape: land - Measures of Australia's Progress, 2006
Themes - Environment & Energy
State of the Environment reporting

LINK TO THE DETAILED SUMMARY