Soil salinity is a major environment problem in Australia caused by both biophysical human factors. It affects many parts of the country, both rural and urban. Unless speedy actions are taken by the government, community and individuals, the problem is going to spread and get worse. The map on the right shows the distribution of the problem in Australia.

What is Salinity?

There is salt in many parts of the Australian landscape. Salinity is the presence of salt in the land surface, in soil or rocks, or dissolved in water in rivers or groundwater. Salinity can develop naturally, but where human intervention has disturbed natural ecosystems, the movement of salt into rivers and onto land has been accelerated. There are different types of salinity according to their causes, including irrigation, dryland, and urban.

Causes of Dryland Salinity

Dryland salinity occurs where removal or loss of native vegetation, and its replacement with crops and pastures that have shallower roots. This results in more water reaching the groundwater system. The groundwater rises to near the surface in low-lying areas. It carries dissolved salts from the soil and bedrock material through which it travels. As saline groundwater comes close to the soil surface (within 2m), salt enters the plant root zone. Even where the groundwater does not bring much salt with it, the waterlogging of the plant root zone alone can damage or kill vegetation.

Trees are like pumps. They help to discharge water through transpiration.

Effects of Dryland Salinity

Dryland salinity has many environmental, economic and social impacts. The costs associated with salinity are potentially enormous and are borne not only by the rural community, but also ultimately by the whole country and its environment. The effects of dryland salinity may impact on:

  1. Agriculture
  2. Water quality
  3. Public infrastructure and urban households
  4. Biodiversity and the environment

Agricultural impacts

The impacts of dryland salinity on soil have adversely affected agriculture in Australia. The consequences include:

Impacts on water usage Dryland salinity may increase salt concentrations in streams and rivers, and has a significant impact on a wide range of uses, including:
Impacts on public infrastructure, buildings and houses

Dryland salinity also affects rural towns. Apart from land clearing, salinity there is partly caused by human activities such as over watering of gardens and sports grounds. It has potential effects on infrastructure, buildings and domestic houses. The impacts include:

Impacts on biodiversity and the environment

Rising water tables and increasing salinity have serious impacts on native vegetation, in the same way as they do for crops and pastures. Remnant vegetation may be threatened and with this, a variety of animal species and their habitats.


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