Rising water tables and ocean salt carried in rain have created destructive levels of salinity in Australia, according to a report released this week. The levels have risen at such a rate that scientists have predicted an area larger than Ireland will be eaten up by salt within the next half century.

Information released in a government- sponsored report by the National Land and Water Resources Audit said the salinity is primarily concentrated in the country's coastal regions, from northern Cape York Peninsula and stretching through prime agricultural areas in Queensland, New South Wales and Victoria and into South Australia.

The salt is corroding roads, railways and pipes as well killing crops and destroying habitats. The report warned that nearly 620,000 acres (250,000 hectares) of land are being ruined annually. It stated, "Much of the area at risk is Australia's most productive land." Wheat and wool industries are at the greatest risk from the increased salinity.

The researchers said, "Salt stores have developed because there is little capacity to drain the continent of salt and water." But they also blamed European settlers for replacing native vegetation with crops with shallower roots and different seasonal growth, saying the cultivation practices had adversely affected water use.

Cities are at risk because concrete is also vulnerable to salt, and 68 rural communities have already been directly affected. The study reported that 1,000 miles (1,600 km) of railway were currently threatened along with 12,500 miles (19,900 km) of roadways.

Source : National Land and Water Resources