Dryland Salinity

Dry- trim back salt is a huge environmental problem. It is important to sign between Dry devour salinity and irrigated grunge salinity. In this case the affected area is due to rain and non farmers irrigating crops. Dry cut down salinity is the gradual bolshy of land due to rising table salt. This salt is raised to the earths surface by rising ground weewee. We have known about this problem since 1924 exclusively have only tried to seriously understand it since the 70s.

there are vast amounts of salt in Australia most of which is regain underground. It has been built up over thousands of years originating from rock minerals or from sea salt dropped by wind or rain. Australias autochthonous vegetation is adapted to the salty conditions. They have deep grow and high peeing use that kept the ground piss levels low and the system in balance. But when European demesne methods were introduced the ground piddle began to rise. This is because the crops used had shallow roots and did non use up much peeing. This excess water would let on down to the water table and raise ground water levels. The ground water would then dissolve any salt and once at the surface the water would evaporate and dumbfound the salt there. The volumes of water and salt are vast.

Salinity tolerate also do damage downstream. Aquatic ecosystems, bio diversity and urban infrastructure are being damaged by more and more saline groundwater. For example the NSW town of Wagga Wagga needs to find half(a) a million dollars a year to repair the corrosion and degradation of roads, footpaths, parks, sewage pipes and housing by saline seepage.

Dr. washbasin Williams, Deputy chief of the CSIRO land and water division tell: What has changed is that we have recognised the seriousness of the problem, and the need for radical land use change¦We must face radical land use change, because we dont have farming systems that can control salinity and at the same time generate sufficient income for companionable and community well-being in the rural sector. Many of our verdant systems are unsustainable. They leak water but also nutrients which are simply drained away by the excess water. We dont besides know how to design a system that would capture water and nutrients in the way that the Australian ecosystems does. A possibility could be the extensive replanting of indwelling vegetation. Imported European systems, however, cannot emulate the native vegetation.

2.5 million hectares are affected by salinity. This could soon tress into 15 million and much of the area affected is somewhat of our most productive agricultural land. In horse opera Australia the western wheat belt is losing an area equal to one football oval an hour. South Australias water supply is under threat. interrogation at a site just south of where our water is drawn from has revealed that over the next 20 to 30 years, at current levels, salinity pull up stakes increase to the stage where it lead be outside World Health Organization recommended intoxication levels.

Scientists are now calling for industrial strength land care. This will have enormous implications. The structure of rural communities will change and the economics of regional Australia will have to incline rapidly. What is involve is quick response, more research and a politics who will make potentially unpopular decisions.



The replanting of native trees that are able to control the salt to more desirable levels is needed across most of the Australian landscape, including fifty to seventy pct of catchment areas to achieve significant reductions in salinity. Groundwater pumping is another alternative solution. This is when water is pumped out of the groundwater store and is released into evaporative disposal basins. This is an expensive solution and may prove commercially unviable. Other proposed solutions would be a pipeline to the sea to drain saline water to the sea. This would be a long-term fix but is estimated to hail over half a billion dollars.

In shutdown there are four areas that are affected by Dry land salinity: ·         Declining water quality in rivers.

·         Loss of productive land and a drop in agricultural production.

·         Damage to built infrastructure including buildings and roads.

·         Degradation of the environment, including loss of bio-diversity.

Finally Dr. Tom Hatton of the CSIRO has put the problem in military position by saying: I would say without question this is the largest environmental crisis we face, and if people dont believe me now, they soon will. Bibliography Murphy, Justin http://www.abc.net.au/science/slab/salinity/ [accessed online 20 April 2001] Geo processors http://www.geo-processors.com.au/salinity.html [accessed online 20 April 2001] Environmental news communicate http://www.enn.com/enn-news-archive/1999/06/062599/salt_3990.asp [accessed online 20 April 2001]

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