Burdekin River
From Wikipedia, the free encyclopedia
| Burdekin River | |
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| Origin | Seaview Range near Ingham, Queensland |
| Mouth | Pacific Ocean at Upstart Bay, near Ayr, Queensland |
| Basin countries | Australia |
| Length | 710km |
| Source elevation | 1200m (3800 feet) |
| Avg. discharge | 380m3/s (mean) 240/3/s (median annual) - can range from nothing to over 40,000m3/s |
| Basin area | 129,700 km² |
The Burdekin River in Queensland, Australia rises on the western slope of the Seaview Range and flows into the Pacific Ocean at Upstart Bay over 200 km to the southwest of the source. The river was discovered by the expedition led by Ludwig Leichhardt in 1845 and named for Mrs. Thomas Burdekin, who had provided assistance to the expedition.
Apart from the Murray River, it is economically the most important river in Australia, and has the fourth-largest watershed of any exorheic drainage system in Australia. It is also the fourth-largest river in Australia by volume of flow[1], but is so erratic that its discharge can reach the mean discharge of the Yangtze (after two severe cyclones in 1958) or have as many as seven months with no flow whatsoever (as in 1923). This exceedingly erriatic flow is due to the extreme variability of precipitation throughout the entire basin. Annual rainfall at most gauges within the basin can range from 200mm (8 inches) to over 1,600mm (64 inches) depending on the monsoon and the number of cyclones that cross the coast[2]. On the coast itself, the variability is even higher: at Bowen not far from the river's mouth, the annual rainfall has ranged from 216mm in 1915 to over 2,200m in 1950.
Major tributaries feeding the Burdekin River include the Clarke, Sutter, Bowen, Belyando and Cape rivers. The source of the Belyando river in central western Queensland is almost 500 km from the mouth of the Burdekin River, and extends into the typical black-soil grassland of Central Queensland. The Burdekin itself almost reaches the Wet Tropics in its upper reaches.
The Burdekin falls dam, the largest dam in Queensland was constructed west of Ayr and Home Hill and completed in 1987 to form what is also known as Lake Dalrymple. In the delta around Ayr and Home Hill, groundwater is used extensively to irrigate crops of sugar cane, which produce the highest quality sugar from anywhere in Australia. This groundwater is recharged artificially during the extreme flood events that occasionally occur, usually due to a La Niña event.
Although on paper most of the basin of the Burdekin appears perfect for rainfed crops like cotton and maize, in fact the rainfall is so erratic that in almost every year a would-be farmer will experience either too little or too much rain for the crop to mature properly. Thus, most of the basin of the Burdekin can be used only for low-density grazing of sheep and cattle which is less likely to be damaged economically and ecologically by the extreme risks of an extraordinarily erratic climate. The natural vegetation away from the coast is a grassland dominated by perennial Mitchell and annual Flinders grasses, whilst near the coast there are patches of dry eucalypt forest on the typically infertile laterised soils characteristic of most of Australia.
| Burdekin River |
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| Burdekin River |
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