Great Dividing Range

The Great Dividing Range, or the Eastern Highlands, is Australia's most substantial mountain range and the third longest land-based range in the world. The range stretches more than 3,500 kilometres (2,175 mi) from Dauan Island off the northeastern tip of Queensland, running the entire length of the eastern coastline through New South Wales, then into Victoria and turning west, before finally fading into the central plain at the Grampians in western Victoria. The width of the range varies from about 160 km (100 mi) to over 300 km (190 mi).

The sharp rise between the coastal lowlands and the eastern uplands has affected Australia's climate, mainly due to orographic precipitation, and these areas of highest relief have revealed an impressive gorge country.

Terminology

The Dividing Range does not consist of a single mountain range. It consists of a complex of mountain ranges, plateaus, upland areas and escarpments with an ancient and complex geological history. The physiographic division name for the landmass is called the East Australian Cordillera. In some places the terrain is relatively flat, consisting of very low hills. Typically the highlands range from 300 m to 1,600 m in height.

Drainage divide

A drainage divide, water divide, divide, ridgeline,watershed, water parting, or (in Canada) height of land, is the line that separates neighbouring drainage basins. In hilly country, the divide lies along topographical ridges, and may be in the form of a single range of hills or mountains, known as a dividing range. In flat country—especially where the ground is marshy—the divide may be harder to discern.

A valley floor divide is a low drainage divide that runs across a valley, sometimes created by deposition or stream capture.

Since ridgelines are easy to see and agree about, drainage divides are often natural borders defining political boundaries, as with the 18th century North America Royal Proclamation of 1763 that preceded the American Revolution.

Types

Drainage divides can be grouped in three types:

Valley-floor divides

A valley-floor divide occurs on the bottom of a valley and arises as a result of subsequent depositions, such as scree, in a valley through which a river originally flowed continuously.