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47-692: The Mawson Plateau is a 71 km granite batholith at a height of between 600 and 750 m. It is dissected by Saucepan Creek and the Granite Plateau Creek; both are tributaries of the Hamilton Creek. The plateau is bounded by the Hamilton Creek on the north and west, the Granite Escarpment on the east and Freeling Heights in the south. Originally known as the Freeling Heights lower granite plateau, it

94-454: A drainage basin, and there are different ways to interpret that data. In the unlikely event that the gauges are many and evenly distributed over an area of uniform precipitation, using the arithmetic mean method will give good results. In the Thiessen polygon method, the drainage basin is divided into polygons with the rain gauge in the middle of each polygon assumed to be representative for

141-540: A drainage boundary is referred to as watershed delineation . Finding the area and extent of a drainage basin is an important step in many areas of science and engineering. Most of the water that discharges from the basin outlet originated as precipitation falling on the basin. A portion of the water that enters the groundwater system beneath the drainage basin may flow towards the outlet of another drainage basin because groundwater flow directions do not always match those of their overlying drainage network. Measurement of

188-426: A point where surface water is lost underground . Drainage basins are similar but not identical to hydrologic units , which are drainage areas delineated so as to nest into a multi-level hierarchical drainage system . Hydrologic units are defined to allow multiple inlets, outlets, or sinks. In a strict sense, all drainage basins are hydrologic units but not all hydrologic units are drainage basins. About 48.71% of

235-869: Is a large mass of intrusive igneous rock (also called plutonic rock), larger than 100 km (40 sq mi) in area, that forms from cooled magma deep in the Earth's crust . Batholiths are almost always made mostly of felsic or intermediate rock types, such as granite , quartz monzonite , or diorite (see also granite dome ). Although they may appear uniform, batholiths are in fact structures with complex histories and compositions. They are composed of multiple masses, or plutons , bodies of igneous rock of irregular dimensions (typically at least several kilometers) that can be distinguished from adjacent igneous rock by some combination of criteria including age, composition, texture, or mappable structures. Individual plutons are solidified from magma that traveled toward

282-443: Is a major tributary of the Granite Plateau Creek. The name refers to the discovery of two abandoned, or lost, saucepans found at different times, and at separate locations along the creek. One was found hanging from a river red gum at the junction (Saucepan Junction) of Saucepan Creek and the Granite Plateau Creek 30°5′18.9″S 139°27′43.7″E  /  30.088583°S 139.462139°E  / -30.088583; 139.462139 ,

329-400: Is a remote and inaccessible wilderness and it is very unusual to find any modern human artifacts on the plateau. When they are found at, or near significant locations they occasionally contribute to the place name: Stardrop Waterhole is a periodic waterhole upstream of Tee Junction Waterhole and is named after the solitary steel "star dropper" fence post found at the site. Saucepan Creek

376-525: Is a small peak high on the central plateau with 360-degree panoramic views of the plateau, and is named after Lorraine Edmunds, Arkaroola's former information officer, National Parks employee, and conservationist. There are numerous trough-like waterholes along the creeks on the Mawson Plateau, many are ephemeral being subject to adequate rainfall in creek catchments. Ray's Waterhole is a picturesque permanent waterhole on Saucepan Creek. The plateau

423-465: Is fairly clean and rounded rock faces. A well-known result of this process is Half Dome in Yosemite Valley . Drainage basin A drainage basin is an area of land in which all flowing surface water converges to a single point, such as a river mouth , or flows into another body of water , such as a lake or ocean . A basin is separated from adjacent basins by a perimeter,

470-487: Is referred to as " watershed management ". In Brazil , the National Policy of Water Resources, regulated by Act n° 9.433 of 1997, establishes the drainage basin as the territorial division of Brazilian water management. When a river basin crosses at least one political border, either a border within a nation or an international boundary, it is identified as a transboundary river . Management of such basins becomes

517-614: Is the Dead Sea . Drainage basins have been historically important for determining territorial boundaries, particularly in regions where trade by water has been important. For example, the English crown gave the Hudson's Bay Company a monopoly on the fur trade in the entire Hudson Bay basin, an area called Rupert's Land . Bioregional political organization today includes agreements of states (e.g., international treaties and, within

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564-875: Is the Sierra Nevada Batholith , which is a continuous granitic formation that makes up much of the Sierra Nevada in California. An even larger batholith, the Coast Plutonic Complex , is found predominantly in the Coast Mountains of western Canada; it extends for 1,800 kilometers and reaches into southeastern Alaska. A batholith is an exposed area of (mostly) continuous plutonic rock that covers an area larger than 100 square kilometers (40 square miles). Areas smaller than 100 square kilometers are called stocks . However,

611-404: Is used only in its original sense, that of the drainage divide line. A drainage basin's boundaries are determined by watershed delineation , a common task in environmental engineering and science. In a closed drainage basin, or endorheic basin , rather than flowing to the ocean, water converges toward the interior of the basin, known as a sink , which may be a permanent lake, a dry lake , or

658-465: The drainage divide , made up of a succession of elevated features, such as ridges and hills . A basin may consist of smaller basins that merge at river confluences , forming a hierarchical pattern . Other terms for a drainage basin are catchment area , catchment basin , drainage area , river basin , water basin , and impluvium . In North America, they are commonly called a watershed , though in other English-speaking places, "watershed"

705-713: The African Great Lakes , the interiors of Australia and the Arabian Peninsula , and parts in Mexico and the Andes . Some of these, such as the Great Basin, are not single drainage basins but collections of separate, adjacent closed basins. In endorheic bodies of water where evaporation is the primary means of water loss, the water is typically more saline than the oceans. An extreme example of this

752-828: The Continental Divide , northern Alaska and parts of North Dakota , South Dakota , Minnesota , and Montana in the United States, the north shore of the Scandinavian peninsula in Europe, central and northern Russia, and parts of Kazakhstan and Mongolia in Asia , which totals to about 17% of the world's land. Just over 13% of the land in the world drains to the Pacific Ocean . Its basin includes much of China, eastern and southeastern Russia, Japan,

799-714: The Korean Peninsula , most of Indochina, Indonesia and Malaysia, the Philippines, all of the Pacific Islands , the northeast coast of Australia , and Canada and the United States west of the Continental Divide (including most of Alaska), as well as western Central America and South America west of the Andes. The Indian Ocean 's drainage basin also comprises about 13% of Earth's land. It drains

846-545: The brown toadlet ( Pseudophryne bibroniiand ), water spiders ( Dolomedes spp. ) and small populations of unidentified fish. The fish are possibly spangled perch, ( Leiopotherapon unicolor ) a widely distributed desert fish common in much of the Hamilton Creek Catchment, or Lake Eyre Hardyhead, ( Craterocephalus eyresii ) the most common and widely distributed fish in the Flinders Ranges. Despite

893-465: The Mawson Plateau at ~700m, rainfall averages are likely to be higher than those at Arkaroola. Maier and Wright found that increased rainfall at altitude was predominantly winter rainfall, however the area is strongly influenced by summer storms. The influence of these unpredictable summer storms is reflected in the differences between the highest and lowest annual rainfall records recorded at Arkaroola (56mm – 949mm). Similar variations certainly occur on

940-479: The Mawson Plateau. The plateau is a drainage basin for the Granite Plateau Creek, and its major tributary, Saucepan Creek. Both of these creeks flow only briefly after rain and as the region receives highly variable rainfall, water is scarce for most of the year and both creeks are ephemeral . In places the creeks have cut deep gorges and valleys into the plateau’s granite creating permanent and semi-permanent waterholes that support numerous species of frogs including

987-623: The US, interstate compacts ) or other political entities in a particular drainage basin to manage the body or bodies of water into which it drains. Examples of such interstate compacts are the Great Lakes Commission and the Tahoe Regional Planning Agency . In hydrology , the drainage basin is a logical unit of focus for studying the movement of water within the hydrological cycle . The process of finding

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1034-412: The base of the cliff there are permanent waterholes containing water spiders ( Dolomedes spp. ). The name of the cliff refers to the spider’s habit of submerging below the surface to hunt, or avoid predation, while breathing from bubbles of air attached to hairs on its abdomen. Edmunds Hill 30°6′12.4″S 139°25′17.2″E  /  30.103444°S 139.421444°E  / -30.103444; 139.421444

1081-406: The basin, it can form tributaries that change the structure of the land. There are three different main types, which are affected by the rocks and ground underneath. Rock that is quick to erode forms dendritic patterns, and these are seen most often. The two other types of patterns that form are trellis patterns and rectangular patterns. Rain gauge data is used to measure total precipitation over

1128-430: The discharge of water from a basin may be made by a stream gauge located at the basin's outlet. Depending on the conditions of the drainage basin, as rainfall occurs some of it seeps directly into the ground. This water will either remain underground, slowly making its way downhill and eventually reaching the basin, or it will permeate deeper into the soil and consolidate into groundwater aquifers. As water flows through

1175-441: The drainage area is dependent on the soil type. Certain soil types such as sandy soils are very free-draining, and rainfall on sandy soil is likely to be absorbed by the ground. However, soils containing clay can be almost impermeable and therefore rainfall on clay soils will run off and contribute to flood volumes. After prolonged rainfall even free-draining soils can become saturated , meaning that any further rainfall will reach

1222-697: The drainage basin to the mouth, and may accumulate there, disturbing the natural mineral balance. This can cause eutrophication where plant growth is accelerated by the additional material. Because drainage basins are coherent entities in a hydrological sense, it has become common to manage water resources on the basis of individual basins. In the U.S. state of Minnesota , governmental entities that perform this function are called " watershed districts ". In New Zealand, they are called catchment boards. Comparable community groups based in Ontario, Canada, are called conservation authorities . In North America, this function

1269-577: The early 1980s by the owners of the Arkaroola pastoral lease. The Granite Escarpment also appears on the Yudnamutana 1:50000 topographical map. It is a high ridge of exposed and weathered granite overlooking Lake Frome. In a gorge on Granite Plateau Creek there is a high granite cliff known to bushwalkers as Aqualung Wall 30°5′12.5″S 139°27′51.3″E  /  30.086806°S 139.464250°E  / -30.086806; 139.464250 . At

1316-857: The eastern coast of Africa, the coasts of the Red Sea and the Persian Gulf , the Indian subcontinent , Burma, and most parts of Australia . The five largest river basins (by area), from largest to smallest, are those of the Amazon (7 million km ), the Congo (4 million km ), the Nile (3.4 million km ), the Mississippi (3.22 million km ), and the Río de la Plata (3.17 million km ). The three rivers that drain

1363-583: The greatest portion of western Sub-Saharan Africa , as well as Western Sahara and part of Morocco . The two major mediterranean seas of the world also flow to the Atlantic. The Caribbean Sea and Gulf of Mexico basin includes most of the U.S. interior between the Appalachian and Rocky Mountains , a small part of the Canadian provinces of Alberta and Saskatchewan , eastern Central America ,

1410-435: The ground and along rivers it can pick up nutrients , sediment , and pollutants . With the water, they are transported towards the outlet of the basin, and can affect the ecological processes along the way as well as in the receiving water body . Modern use of artificial fertilizers , containing nitrogen (as nitrates ), phosphorus , and potassium , has affected the mouths of drainage basins. The minerals are carried by

1457-781: The ground at its terminus, the area can go by several names, such playa, salt flat, dry lake , or alkali sink . The largest endorheic basins are in Central Asia , including the Caspian Sea , the Aral Sea , and numerous smaller lakes. Other endorheic regions include the Great Basin in the United States, much of the Sahara Desert , the drainage basin of the Okavango River ( Kalahari Basin ), highlands near

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1504-639: The islands of the Caribbean and the Gulf, and a small part of northern South America. The Mediterranean Sea basin, with the Black Sea , includes much of North Africa , east-central Africa (through the Nile River ), Southern , Central, and Eastern Europe , Turkey , and the coastal areas of Israel , Lebanon , and Syria . The Arctic Ocean drains most of Western Canada and Northern Canada east of

1551-455: The majority of batholiths visible at the surface (via outcroppings) have areas far greater than 100 square kilometers. These areas are exposed to the surface through the process of erosion accelerated by continental uplift acting over many tens of millions to hundreds of millions of years. This process has removed several tens of square kilometers of overlying rock in many areas, exposing the once deeply buried batholiths. Batholiths exposed at

1598-514: The most water, from most to least, are the Amazon, Ganges , and Congo rivers. Endorheic basin are inland basins that do not drain to an ocean. Endorheic basins cover around 18% of the Earth's land. Some endorheic basins drain to an Endorheic lake or Inland sea . Many of these lakes are ephemeral or vary dramatically in size depending on climate and inflow. If water evaporates or infiltrates into

1645-599: The other was found near a major waterfall on Saucepan Creek. The plateau is located within one of Australia ’s major bioclimatic regions-the arid Eyrean region. Average rainfall on the adjoining pastoral lease of Arkaroola is 265 mm; however the Gammon Ranges Rainfall Project (Maier and Wright 1996), which began monitoring rainfall on the nearby Gammon Plateau at 930m in 1988 indicated that rainfall and number of rain days increases with altitudes greater than 400m above sea level in this area. With

1692-418: The rainfall on the area of land included in its polygon. These polygons are made by drawing lines between gauges, then making perpendicular bisectors of those lines form the polygons. The isohyetal method involves contours of equal precipitation are drawn over the gauges on a map. Calculating the area between these curves and adding up the volume of water is time-consuming. Isochrone maps can be used to show

1739-680: The relative abundance of permanent water, mammals and birds are sparse on the plateau, but there are small populations of euros ( Macropus robustus ), echidnas ( Tachyglossus aculeatusand ) and a few species of bats. Feral goats are rare. Common birds include willie wagtail ( Rhipidura leucophrys ), wedge-tailed eagle ( Aquila audax ), and the Australian boobook ( Ninox boobook ). Reptiles have fared better than mammals and there are numerous species of snakes, skinks and dragons. Batholith A batholith (from Ancient Greek bathos  'depth' and lithos  'rock')

1786-631: The responsibility of the countries sharing it. Nile Basin Initiative , OMVS for Senegal River , Mekong River Commission are a few examples of arrangements involving management of shared river basins. Management of shared drainage basins is also seen as a way to build lasting peaceful relationships among countries. The catchment is the most significant factor determining the amount or likelihood of flooding . Catchment factors are: topography , shape, size, soil type, and land use (paved or roofed areas). Catchment topography and shape determine

1833-461: The river rather than being absorbed by the ground. If the surface is impermeable the precipitation will create surface run-off which will lead to higher risk of flooding; if the ground is permeable, the precipitation will infiltrate the soil. Land use can contribute to the volume of water reaching the river, in a similar way to clay soils. For example, rainfall on roofs, pavements , and roads will be collected by rivers with almost no absorption into

1880-418: The speed with which the runoff reaches a river. A long thin catchment will take longer to drain than a circular catchment. Size will help determine the amount of water reaching the river, as the larger the catchment the greater the potential for flooding. It is also determined on the basis of length and width of the drainage basin. Soil type will help determine how much water reaches the river. The runoff from

1927-465: The surface are subjected to huge pressure differences between their former location deep in the earth and their new location at or near the surface. As a result, their crystal structure expands slightly over time. This manifests itself by a form of mass wasting called exfoliation . This form of weathering causes convex and relatively thin sheets of rock to slough off the exposed surfaces of batholiths (a process accelerated by frost wedging ). The result

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1974-405: The surface from a zone of partial melting near the base of the Earth's crust. Traditionally, these plutons have been considered to form by ascent of relatively buoyant magma in large masses called plutonic diapirs . Because the diapirs are liquified and very hot, they tend to rise through the surrounding native country rock , pushing it aside and partially melting it. Most diapirs do not reach

2021-652: The surface to form volcanoes , but instead they slow down, cool, and usually solidify 5 to 30 kilometers underground as plutons (hence the use of the word pluton ; in reference to the Roman god of the underworld Pluto ). An alternate view is that plutons are formed by aggregation of smaller volumes of magma that ascend as dikes . A batholith is formed when many plutons converge to form a huge expanse of granitic rock. Some batholiths are mammoth, paralleling past and present subduction zones and other heat sources for hundreds of kilometers in continental crust . One such batholith

2068-415: The time taken for rain to reach the river, while catchment size, soil type, and development determine the amount of water to reach the river. Generally, topography plays a big part in how fast runoff will reach a river. Rain that falls in steep mountainous areas will reach the primary river in the drainage basin faster than flat or lightly sloping areas (e.g., > 1% gradient). Shape will contribute to

2115-477: The time taken for runoff water within a drainage basin to reach a lake, reservoir or outlet, assuming constant and uniform effective rainfall. Drainage basins are the principal hydrologic unit considered in fluvial geomorphology . A drainage basin is the source for water and sediment that moves from higher elevation through the river system to lower elevations as they reshape the channel forms. Drainage basins are important in ecology . As water flows over

2162-673: The world's land drains to the Atlantic Ocean . In North America , surface water drains to the Atlantic via the Saint Lawrence River and Great Lakes basins, the Eastern Seaboard of the United States, the Canadian Maritimes , and most of Newfoundland and Labrador . Nearly all of South America east of the Andes also drains to the Atlantic, as does most of Western and Central Europe and

2209-553: Was renamed The Mawson Plateau after Sir Douglas Mawson . The main creek on the plateau has been known by successive owners of the Mount Freeling pastoral lease as the Granite Plateau Creek. T Junction Waterhole appears on the Yudnamutana 1:50000 topographical map and is ~100m downstream from a distinctive T-junction on Granite Plateau Creek. The waterhole is the location of an old emergency rations cache put there in

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