Heretic Posted January 31, 2013 I have seen reports on " Landline " and elsewhere that the problem of increasing soil salinity is a result of rising ground-water levels , which bring brackish / salty water close to the surface where evaporation increases the salinity . It was reported that before invasion / colonisation / farming and land clearing , the ground water levels were much lower than they are today because the original native trees and vegetation transpired much groundwater , creating the lower water levels . Furthermore , irrigation is said to exacerbate the high levels of groundwater and salinty . . . Whenever I travel by air between Brisbane - Sydney - Melbourne - Adelaide I am astonished , appalled and saddened at the extent of the cleared bush land below . It seems that apart from a few mountainous regions , virtually all of S.E . Australia is paddocks and farm land . I am wondering now that if the de-foliation of Australia , and the rising groundwaters , are exacerbating the recent floods to any significant extent ??? ... Any ideas and / or opinions ?? Share this post Link to post Share on other sites
Distracted Posted January 31, 2013 I think that the urban scrawl has a massive impact on extreme weather events. A very unscientific view but one none the less. This is somewhat related WASHINGTON -- Heat rising up from cities such as New York, Paris and Tokyo might be remotely warming up winters far away in some rural parts of Alaska, Canada, and Siberia, a surprising study theorizes. In an unusual twist, that same urban heat from buildings and cars may be slightly cooling the autumns in much of the Western United States, Eastern Europe and the Mediterranean, according to the study published Sunday in the scientific journal Nature Climate Change. Meteorologists long have known that cities are warmer than rural areas, with the heat of buildings and cars, along with asphalt and roofs that absorb heat. That's called the urban heat island effect and it's long been thought that the heat stayed close to the cities. But the study, based on a computer model and the Northern Hemisphere, now suggests the heat does something else, albeit indirectly. It travels about half a mile up into the air and then its energy changes the high-altitude currents in the atmosphere that dictate prevailing weather. http://www.wunderground.com/news/urban-heat-island-study-20130127 3 Share this post Link to post Share on other sites
Halcyon Daze Posted January 31, 2013 Native veg slows the flow of runoff water, even into the soil itself ( a cause of salinity). Rivers such as the Murray ran clear before ' white man' came and rain in one area would take much longer to reach it's final destination into the sea. 1 Share this post Link to post Share on other sites
Zen Peddler Posted February 3, 2013 An old person once said to me that the best way to fix the economy was to chop down more trees. People thought about it very differently in the old days Share this post Link to post Share on other sites