Deforestation
When forests are cut, the salinity of the soil can greatly increase. As a result, saline water draining from such areas can affect downstream or downslope water quality. It is estimated that around 7% of the agricultural area of western Australia is suffering from this problem following deforestation.
Moreover, studies in Australia's wet tropics show that soils have limited capacity to recover from deforestation. This adds to deforestation's price tag. Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO) estimates that land degradation costs about $1 billion annually.