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A description of salinity in both the rivers and on the land

Type of salinity and their prevention There are different types of salinity, each with different causes and varying treatment.

Related terms:

Dryland salinity Dryland salinity is the accumulation of salts in the soil surface and groundwater in non-irrigated areas. It is usually the result of three broad processes: Often it results from replacing deep-rooted native vegetation with shallower-rooted crops and pastures, which take up less water. Unused rainwater leaks into the ground causing groundwater to rise and dissolve salts stored deep in the soil.

The salty water may: Rising groundwater alone does not automatically cause salinity, but the wide distribution of saline soils in Australia means it is likely that it will mobilise salt stored in the soil. Treatment expand The NSW Government is working with the Australian Government, local government, farmers and the broader community to treat and prevent the different types of salinity. The key to addressing dryland salinity is managing excess water in the landscape.

water salinity

This can be done by: Under appropriate conditions, salt-affected sites can be treated by: The NSW Government also provides other detailed resources for land managers who need to assess and manage salinity on the Department of Primary Industries Salinity webpage.

Modelling dryland salinity allows us to: Models help us to understand salinity processes in a landscape. We need to know: Several models have been used in NSW to help answer these questions: PERFECT Used at a property scale, this well-established tool estimates surface runoff, lateral flow, recharge and the impacts of vegetation changes on the water cycle.

In 2015, this model was used to forecast the impacts of climate change on surface runoff and recharge.

Understanding Salinity

In NSW, it has been applied in the: CERAT risk assessment tool to help identify and prioritise land use planning decisions to protect and preserve the health of coastal estuaries. The model predicts the impacts of various land use scenarios on catchment water yield and salinities to stream.

This predicts land use impacts at paddock, hillslope and catchment scales. It can be used for modelling water balance, solute balance, vegetation growth, recharge-discharge dynamics, lateral flow and streamflow.

Irrigation salinity Irrigation salinity is the rise in saline groundwater and the build-up of salt in the soil surface in irrigated areas. It is caused by using large volumes of irrigation water that locally raise groundwater levels and mobilise salt. Irrigation salinity is made worse when water used to irrigate is from salty sources.

Type of salinity and their prevention

Irrigation salinity can be controlled by using water efficiently. Crops should receive only the amount of water they can actually use. Reducing water usage in irrigated areas generally requires changes to irrigation infrastructure and technology, and better matching of crops to soil types.

Management and engineering practices that might be used include: Urban salinity Urban salinity is a combination of dryland and irrigation salinity processes and is mainly caused by rising groundwater bringing salts to the land surface.

The rise in groundwater is caused by blocked or changed natural drainage paths due to: In the urban environment, other sources of salt that can contribute to urban salinity include: