1.1 The physical environment of NSW
New South Wales, Australia's most populous state, is located in the south-east of the Australian continent. The state has an area of 800,642 square kilometres, approximately 10% of the total Australian landmass (Geoscience Australia 2008). Management of the NSW environment is made challenging by the diversity and complexity of the state's landscapes and ecosystems. The fertile agricultural areas along the coast and on the western slopes of the Great Dividing Range contrast with the semi-arid plains in the state's west, while the alpine and highland areas along the Great Dividing Range contrast with the coastal lowlands. NSW also boasts a diverse network of marine parks, including the World Heritage-listed Lord Howe Island.
Map 1.1: Relief map of NSW
Climatic conditions
The climate of NSW is highly variable. While annual total rainfall across the state has generally decreased over the past 60 years (Map 1.2), NSW has also experienced a variety of extreme weather events, including storms and floods. The north-east of the state experiences predominantly summer rainfall and relatively dry winters. By contrast, agriculture in the south depends on regular rainfall from the cold fronts and cut-off lows that pass through south-eastern Australia during the winter growing season.
Map 1.2: Trend in annual total rainfall, 1950–2008
NSW has four distinct climate zones due to the influence of the Great Dividing Range: the high country, the coast, the western slopes of the range and the western plains. Temperature and rainfall vary greatly across these regions: for example, the higher elevations of the range are the coldest areas, while the north-west plains are the hottest; the east coast receives the most precipitation and the western areas of the state the least.
Natural variations in temperature and rainfall in NSW are influenced by the combined pressures on the eastern Australian climate of the El Niño – Southern Oscillation (ENSO), the Southern Annular Mode and the Indian Ocean Dipole (IOD).
It is now widely accepted that climate change also affects weather patterns, causing drier-than-average conditions and an increase in extreme weather events, such as heatwaves and droughts (CSIRO & BoM 2008); see the Climate Change Chapter for more details. Other atmospheric issues, including air quality, are discussed in the Atmosphere Chapter.
Hydrology
Hydrological issues are closely linked to changes in the climate of NSW. In early 2009, over half of NSW was classified as being in drought (Map 1.3). Drought levels have fluctuated over the past three years, with the worst conditions seen in February 2007 when 96.3% of the state was classified as being in drought. The impact of drought on water flows and the condition of rivers, wetlands, estuaries and coastal lakes in NSW is discussed in the Water Chapter.
Map 1.3: Drought declared areas in NSW, July 2009
Land
Australian soils are among the oldest and most fragile in the world. The health of our soil has a direct impact on the health of the state's biodiversity, water systems and agricultural productivity. There are many complex problems associated with NSW soils, including desertification, soil degradation, salinity, acidification and land contamination. The Land Chapter analyses the pressures, impacts and responses of soil-related issues in further detail.
Biodiversity
Australia's extreme conditions and geographic isolation have resulted in a unique and diverse range of flora and fauna inhabiting the continent. Australia is home to more than one million species of native plants and animals, but modification of the natural environment since European settlement, including large-scale clearing and the introduction of invasive species, has resulted in high rates of extinction, particularly of mammals. In NSW, over 1000 native species, populations and ecological communities are currently listed as threatened with extinction. Further issues concerning biodiversity in NSW are explored in the Biodiversity Chapter.
Mineral and energy resources
NSW has substantial mineral resources, yielding a broad range of mineral and energy products, including coal, metals, and industrial and construction minerals. The total value of mining production in 2006–07 was $12.3 billion. The minerals industry is the state's largest export industry with coal, copper and gold as minerals and iron, steel and aluminium as processed metals the main mineral industry exports (DPI 2008).
Coal production accounted for approximately 66% of the total value of NSW mineral production in 2006–07. The Sydney–Gunnedah Basin contains most of the coal resources of NSW, with smaller quantities in the Gloucester and Oakland basins. Recoverable coal reserves are estimated to be over 12 billion tonnes. The NSW coal mining industry produced around 170.3 megatonnes (Mt) of raw coal in 2006–07, yielding 131.3 Mt of saleable coal, reflecting a 6% increase from the previous year's production (DPI 2009).
Coal and energy consumption is discussed further in Human Settlement 3.2.
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