WATER: Australia Flashcards
how has human activity contributed to an increased risk of drought in the Sahel Region?
a
millennium drought 1997-2009
longest uninterrupted series of years with below median rainfall in south-easter Australia since at least 1900
meteorological causes of millennium drought
El Nino events 2002-2003 and 2006-2007 caused two-thirds fo the rainfall deficit in eastern Australia
strengthened STR accounted for 80% of the rainfall decline in south-eastern Australia by blocking storm tracks (depressions), forcing them towards lower latitudes, reducing the frontal rainfall
human causes of millennium drought
changes to Hadley Cell and STR associated with anthropogenic global warming
STR intensified due to global surface temperature increase resulting from human emissions
anthropogenic warming reducing the temperature gradient between the Equator and the Poles, subsequently reducing the energy available for the mid-latitude storm systems and the polar front jet stream
‘Big Dry’ of 2006
this was assessed as a 1-1000 event
The Murray-Darling Basin (MDB)
home to more than 2 million people
contains two rivers, the Murray and the Darling
covers 14% of the Australian land mass
provides 75% of Australia’s water and 85% of the country’s irrigation water
provides 40% of the nation’s farm produce
environmental concerns of the IMD
increasing and competing demands which has increased by 5x since 1920, which has not always been well managed or co-ordinated
the difficulties are because the
