Landform Regions of Australia

•Australia has 4 main landform regions classified by climate, geology, tectonics, and elevation.

1.Eastern Highlands - Great Dividing Range, high mountains and gorges cut by rivers

2.Interior Lowlands – Dry, low lying desert in the centre of Australia

3.Western Plateau – Geologically old, tectonically stable and flat landscape

4.Coastal Plains – Cape York to Victoria, low lying, estuaries and deltas, dense populations

The Australian landscape owes its distinct form to its geological and climate history.

The processes that change the landscape can be broadly placed into two classes: weathering and erosion.

Weathering is the breakdown and dissolution of rocks via mechanical or chemical means. Weathering weakens rocks and allows for erosion processes to further fragment and transport material across the continent.

Erosion refers to the surface processes that remove soil, rock, or any material (e.g. dissolved salts) from one location and then transport it to another. The surface processes are generally associated with wind (aeolian) and water (fluvial and marine).

Coastal Regions

Coastal regions are more active and have combined marine, aeolian and fluvial processes. Waves erode cliffs, move sediment around and build the beaches. Winds create the dune fields, such as those found on North Stradbroke Island, QLD, and the rivers gouge out valleys, create flood plains, and transport sediment towards the coast.

Click on the numbers below to explore some coastal processes and formations.

Eastern Highlands:

The highland region of Australia features higher rainfall than most of the continent. The combination of rain and river flow leads to the erosion of the landscape and the creation of river valleys, escarpments and flood plains.

Interior Lowlands:

The interior lowlands feature rivers that flow from the mountains in the Great Dividing Range towards the southwest.

Rivers like the Murray or the Darling have sufficient water (due to ground water) year round to permanently flow. The higher elevation at the start of these rivers means the rivers flow faster than in the nearly flat landscapes in the semi-arid and arid regions of Australia (such as the Lake Eyre Basin). In these regions fluvial (or river) processes drive most of the change on the landscape, especially in the flood plains. Flood events are important in both recharging the flood plains with water and in changing the geomorphology of the flood plains and the river channels.

The lowlands also feature flat arid environments where the low gradient leads to slow flowing rivers when there is water even available. The high interannual variability in rainfall, the high evapotranspiration and the low flow in the rivers leads to a flat landscape without the distinctive river channels like the Murray or the Darling. The water that does flow in basins like Lake Eyre is usually evaporated before reaching the coast. This contributes to the flat landscape as sediment that is eroded is redistributed into areas with lower elevation but not discharged to the coast.

Winds in the interior lowlands can create sand dunes in the semi arid environment even in locations nearby some of the major rivers.

Western Plateau

The climate in the Western Plateau is arid with very little rainfall and fluvial processes. Winds are the main driver of erosion and change as evidenced by the large longitudinal dunes systems.