Water resources and environment in Australia

Abstract

Australia is the driest inhabited continent in the world: the mean annual rainfall is only about 465 mm. The country has also one of the most variable climates in the world: tropical in the north to arid in the middle to temperate in the south, and still others (e.g. continental, oceanic). As a consequence, there is significant variability in hydrology and water resources (e.g. rainfall, streamflow) in both space and time: for instance, more than 80 % of the country gets an annual rainfall of \600 mm, but the tropical far north receives over 4,000 mm; and rainfall is generally more in winter than in summer, but it is the opposite in the far north. The extreme spatial and temporal variability in rainfall also contributes to frequent floods and droughts in different parts of the country: the 2010‐2011 floods in the northeast state of Queensland (QLD) and the 2001‐2009 drought (the Millennium Drought) in the southeast states of New South Wales (NSW), Victoria (VIC), and Tasmania (TAS) and also the Australian Capital Territory (ACT) are just two of the many recent examples. Australia is an island continent, far away from much of the rest of the world. It is also home to some unique ecosystems and species. The Great Barrier Reef is the world’s largest coral reef system, composed of over 2,900 individual reef systems and 900 islands stretching for over 2,600 km over an area of *344,000 km 2 , located in the Coral Sea off