Alligator Rivers
Alligator | |
---|---|
mouth in the Northern Territory | |
Location | |
Country | Australia |
Territory | Northern Territory |
Physical characteristics | |
Mouth | |
• location | Australia |
• coordinates | 12°14′22″S 132°24′11″E / 12.23944°S 132.40306°E |
[1] |
Alligator Rivers is the name of an area in an
Rivers
The East Alligator River is about 160 km (99 mi) long. After rising in the northern part of the Arnhem Land Plateau, it flows with tributary streams towards the northwest, through canyons towards the Van Diemen Gulf, which it meets at Point Farewell. The river has a total catchment area of 15,876 km2 (6,130 sq mi)[2] and has many tributaries, including Magela Creek, Tin Camp Creek, and Cooper Creek.[3] The catchment is surrounded by the South Alligator River catchment to the west and Goomadeer and Liverpool River catchments to the east and the Daly River catchment to the south. The river has an annual average discharge of 6,870 gigalitres (8.986×109 cu yd) per year.[4]
The South Alligator River is also about 160 km (99 mi) long. It rises north of Mount Stow, on the Arnhem Land Plateau. It flows northwesterly in a valley containing a number of disused uranium mines developed between 1955 and 1965. It also flows out into the Van Diemen Gulf of the Timor Sea. The catchment area occupies an area of 11,917 km2 (4,601 sq mi) and has the East Alligator River catchment to the east, the Wildman and Mary River catchments to the west, and the Daly River catchment to the south.[2]
The West Alligator River rises in the lowlands and is 80 km (50 mi). The
The rivers have created the alluvial plains, including the mangrove swamps, in the past 20,000 years.
Climate
Like much of northern Australia, the Alligator Rivers region has a monsoon climate. The dry season lasts between May and September while the wet season lasts between November and March. April and October are transitional periods between the two seasons. Annual rainfall at Jabiru is around 1.54 m (5.1 ft), with almost all of it falling during the wet season. During the wet season, the prevailing winds are westerly to northwesterly, while they are easterly to southeasterly during the dry season.
The three Alligator Rivers are
During the wet season, the savanna turns green, the wildlife spreads out, the bird life returns, and the streams flood into adjacent lands turning them into swamps. The flood plains leave behind silt when they gradually dry up during the wet season.
During the wet season, the water has a higher temperature and is relatively low in turbidity. In the dry season, an increase in turbidity occurs, especially in the shallower water sources.
The Alligator Rivers region is also subject to cyclones between October and May, like other parts of the Australian Indian Southeast region.
Wildlife
The region takes its name from the crocodiles in the lower reaches of the rivers. However, the region features a wide diversity of plant and animal habitats. More than 1,500 species of
The region also features high populations of the
Some threat to the
Birds
Aboriginal culture
The southern part of Kakadu contains a number of sites relating to Bula,[7] a god associated with creation, and these sites are considered to be both sacred and dangerous to the aboriginal people because of this association. Also, art relating to contact with Makassan traders and Europeans is found there.
At Ubirr Rock near Cahill's Crossing on the East Alligator River, some paintings dating from 20,000 years ago have figures throwing spears and wearing headdresses to first contact with European settlement.
The
The Jawoyn people live in the South Alligator and South Mary regions, as well as around Katherine. The Jawoyn negotiated an agreement in 1993 for the Coronation Hill uranium mine where they would allow further exploration of the area in return for employment and training for the Jawoyn and a partnership arrangement.
The
Modern history
Exploration
The explorer
Ludwig Leichhardt was the first European explorer to visit the area in 1845 en route to Port Essington. Leichhardt followed a creek down from the Arnhem Land escarpment before crossing the South and East Alligator Rivers. John McDouall Stuart also visited the area in 1862.
Settlement
See Kakadu National Park for more information on settlement.
The settlement of the area by Europeans was slow and sporadic as it was very remote and illnesses were also a problem. The commercial harvesting of
Paddy Cahill had established his cattle station at Oenpelli by 1906, and by 1913, it had become successful. Indeed, Cahill's success at Oenpelli was often cited as an example for others to follow. Other stations were set up, but did not always enjoy the same success. Goodparla operated as a cattle and buffalo station and operated with mixed success until the federal government acquired the land as part of Kakadu National Park.
Small-scale gold mining started in the region in the 1920s at Imarlkba near Barramundi Creek and at Moline in the 1930s. However, the discovery of uranium at the headlands of the South Alligator River in 1953 started the mining industries. By 1957, 13 uranium mines were operating, employing 150 people including at Coronation Hill. Following the discovery of large uranium mines at
See also
- List of rivers of Northern Territory
References
- ^ "Map of South Alligator River, NT". Bonzle Digital Atlas of Australia. Retrieved 5 May 2015.
- ^ Commonwealth of Australia. 2005. Archived from the original(PDF) on 1 April 2015. Retrieved 7 May 2015.
- ^ Mike Saynor and Wayne Erskine. "Downstream changes in river reaches from the catchment to the sea in the East Alligator River basin, northern Australia". Retrieved 7 May 2015.
- ^ Murray Smith; Dr Mohsin Hafeez. "Optimising Australia's contribution to Asia's food bowl" (PDF). Archived from the original (PDF) on 18 May 2015. Retrieved 9 May 2015.
- ^ "Moth joins Kakadu weed battle". CSIRO. Archived from the original on 21 October 2013. Retrieved 14 August 2013.
- ^ "IBA: Alligator Rivers Floodplains". Birdata. Birds Australia. Archived from the original on 19 July 2011. Retrieved 19 May 2011.
- ^ Garde, Murray. "bula". Bininj Kunwok online dictionary. Bininj Kunwok Regional Language Centre. Retrieved 16 June 2019.
- ^ Garde, Murray. "ngalyod". Bininj Kunwok online dictionary. Bininj Kunwok Regional Language Centre. Retrieved 16 June 2019.
- ^ Lieutenant Phillip Parker King, Narrative of a Survey of the intertropical and western coasts of Australia 1826 entry for 6 May 1818 cited in Webster World 23 October 2005
External links
- Australian Government Department of the Environment and Heritage Introduction to the Alligator Rivers Region
- Kakadu National Park East Alligator River page
- Australian Government Department of the Environment and Heritage page on the South Alligator River
- Northern Territory Visitors Bureau page on Kakadu and Alligator Rivers tours
- CSIRO publication on Alligator Rivers birdlife
- "Arnhem Land tropical savanna". Terrestrial Ecoregions. World Wildlife Fund.
- Australian Government culture and recreation site about Kakadu
- Department of the Environment and Heritage article on Kakadu
- Alex Barlow and Marji Hill editors Encyclopedia of Australia's Aboriginal People Macmillan Education Australia 2000 accessed through MacquarieNet Online