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52-429: The stream is about 25 miles (40 km) long and heads in the mountain mass dominated by Pyramid Peak, from which Chititu Creek, Dan Creek, and Canyon Creek receive much of their waters. The water of Young Creek is derived in part from melting snow and glacier ice, and during the warm summer days is discolored with glacial silt. Young Creek occupies a typical glacial valley of broad U-shaped cross section. The upper part of

104-484: A sink , which may be a permanent lake, a dry lake , or 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

156-414: A watershed , though in other English-speaking places, "watershed" 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

208-446: A basin they form centripetal or inland drainage pattern. A deranged drainage system is a drainage system in drainage basins where there is no coherent pattern to the rivers and lakes. These can form in areas with extensive limestone deposits, where surface streams can disappear into the groundwater via caves and subterranean drainage routes. They can also form in areas where there has been much geological disruption. A classic example

260-603: A central playa . An axial river existed in the Espanola Basin as early as 13 million years ago, reaching the Santo Domingo Basin by 6.9 million years ago. However, at this time, the river drained into a playa in the southern Albuquerque Basin where it deposited the Popotosa Formation . The upper reach of this river corresponded to the modern Rio Chama , but by 5 million years ago, an ancestral Rio Grande draining

312-504: A central high point. Volcanos usually have archetypal features on which this commonly develops are modest or hard domes pattern develops when streams flow in many general directions (meaning quite long-term) In India, the Amarkantak range and Ramgarh crater are most archetypal; and Dogu'a Tembien in Ethiopia . When the streams converge at a point, which is generally a depression or

364-424: A depth of about 500 feet (150 m). From this point westward, the canyon becomes broader and shallower till the creek reaches the bars of Nizina River. The Nizina gold field includes the drainage basins of three southeast tributaries of the upper Nizina River—Young Creek, Chititu Creek, and Dan Creek. Young Creek is the largest of the three streams, and its crescent-shaped basin surrounds that of Chititu Creek on

416-449: 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

468-540: 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

520-406: A drainage system develops on a surface composed of 'younger' rocks, but due to denudation activities this surface of younger rocks is removed and the river continues to flow over a seemingly new surface, but one in fact made up of rocks of old geological formation. Dendritic drainage systems (from Greek δενδρίτης , dendrites , "of or like a tree") are not straight and are the most common form of

572-403: A long distance, much of it from the upper Chitina Valley. 61°21′55″N 142°43′32″W  /  61.3653°N 142.7256°W  / 61.3653; -142.7256 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

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624-573: A single lower base level. An example of an integrated drainage is the area drained by the Rio Grande River . The sedimentary basins forming the modern Rio Grande Valley were not integrated into a single river system draining into the Gulf of Mexico until relatively recent geologic time. Instead, the basins formed by the opening of the Rio Grande rift were initially bolsons , with no external drainage and

676-822: A tangential or greater concentric path along a belt of weak rock so, with others, a roughly traced out ring can be seen. It is best displayed by streams draining a maturely dissected structural dome or basin where erosion has exposed rimming sedimentary strata of greatly varying degrees of hardness, as in the Red Valley , which nearly encircles the domal structure of the Black Hills of South Dakota . Astroblemes and mud diapirs are also thought to be able to cause this kind of drainage pattern. Angular drainage patterns form where bedrock joints and faults intersect at angles other than rectangular drainage patterns. Angles can be more or less than 90 degrees. An integrated drainage

728-429: Is a mature drainage system characteristic of arid climates. It is formed by coalescing of individual basins formerly separated by high ground, such as mountains or ridges. Headward erosion from a lower basin may breach the barrier, as may spilling over from a higher basin due to aggradation (accumulation of sediments in the basin). The effect of integration of a drainage system is to replace local higher base levels with

780-480: 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

832-447: Is separated from adjacent basins by a perimeter, 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

884-491: Is the Canadian Shield . During the last ice age , the topsoil was scraped off, leaving mostly bare rock. The melting of the glaciers left land with many irregularities of elevation and a great deal of water to collect in the low points, resulting in the region's many lakes. The drainage basins are young and are still sorting themselves out; eventually the system will stabilize. In an annular drainage pattern, streams trace

936-600: 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

988-682: 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

1040-792: 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,

1092-681: 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

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1144-433: The groundwater . A drainage basin is an area of land where 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. Drainage system (geomorphology) In geomorphology , drainage systems , also known as river systems , are the patterns formed by the streams , rivers , and lakes in a particular drainage basin . They are governed by

1196-598: 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

1248-406: 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

1300-501: The bulk rock so erosion tends to preferentially open the joints and streams eventually develop along the joints. The result is a stream system in which streams consist mainly of straight line segments with right-angle bends and tributaries join larger streams at right angles. This pattern can be found with the Arun River in Nepal. In a radial drainage system, the streams radiate outwards from

1352-449: The creek channel within the canyon; and flood-plain gravels, over which the stream flows in times of high water. In addition to these deposits, which were transported and deposited chiefly by running water, or by water and ice, there is a thin veneer of morainal debris that is found throughout the valley, and even on the mountain tops. This deposit is made up of material that is in large part foreign to Young Creek and that has been transported

1404-430: 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

1456-441: 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

1508-692: 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

1560-749: The drainage system. In this, there are many sub-tributaries (analogous to the twigs of a tree), which merge into tributaries of the main river (the branches and the trunk of the tree, respectively). They are seen to feed a river channel that matches and is strongly accordant to the overriding gradient of the land. Truly dendritic systems form in V-shaped valleys ; as a result, the rock types must be impervious and non-porous . A parallel drainage system occurs on elongate landforms like outcropping resistant rock bands), typically following natural faults or erosion (such as prevailing wind scars). The watercourses run swift and straight, with very few tributaries, and all flow in

1612-486: The east, south, and west. Calamity Gulch and Gold Run are among the tributaries of Young Creek most frequently mentioned. These flow south from the ridge whose north slope is drained by branches of White Gulch, one of the forks of Chititu Creek. The dominant bedrock of the Young Creek valley is black shale, which is cut by many dikes and sills of light-colored granitic rock and is capped in the high mountains on both sides of

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1664-615: The eastern San Juan Mountains had joined the ancestral Rio Chama. The ancestral Rio Grande progressively integrated basins to the south, reaching the Palomas basin by 4.5 million years ago, the Mesilla basin by 3.1 million years, to Texas by 2.06 million years, and finally joining the Pecos River at 800,000 years to drain into the Gulf of Mexico. Volcanism in the Taos Plateau reduced drainage from

1716-821: 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

1768-567: 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 ,

1820-435: 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

1872-744: 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

1924-572: 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

1976-426: The larger and more detailed the topographic map , the more information is available. Per the lie of channels , drainage systems can fall into one of several categories, known as drainage patterns. These depend on the topography and geology of the land. All forms of transitions can occur between parallel, dendritic, and trellis patterns. A drainage system is described as accordant if its pattern correlates to

2028-506: 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

2080-418: 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

2132-625: 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

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2184-461: 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

2236-527: The same direction. This system forms on very long, uniform slopes, for instance, high rivers flowing southeast from the Aberdare Mountains in Kenya and many rivers of Myanmar . This sometimes indicates a major fault that cuts across an area of steeply folded bedrock. The geometry of a trellis drainage system is similar to that of a common garden trellis . Along a strike valley, smaller tributaries feed into

2288-418: 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

2340-786: The steep slopes of mountainsides. These tributaries enter the main river about perpendicular, causing a trellis-like appearance of the system. They form where hard and soft formations exist on both banks of the main river, and are reflective of height, accentuated by erosion. Trellis drainage is characteristic of folded mountains, such as the Appalachian Mountains in North America and in the north part of Trinidad . Rectangular drainage develops on rocks that are of approximately uniform resistance to erosion , but which have two directions of jointing at approximately right angles or 90 degrees. The joints are usually less resistant to erosion than

2392-452: The stream, formed by the union of two short forks, each a little more than 4 miles (6.4 km) long, flows over a flood plain between low brush-covered gravel benches. Below the big bend, where the stream turns to the west at a right angle to its upper course, Young Creek has intrenched itself in the valley floor and has cut a rather wide canyon that grows deeper and deeper downstream until, 4 miles (6.4 km) below Calamity Gulch, it attains

2444-487: The structure and relief of the landscape over which it flows. A discordant system or pattern does not correlate to the topography and geology of the area. Discordant drainage patterns are classified into two main types: antecedent and superimposed , while ante position drainage patterns combine the two. In antecedent drainage, a river's vertical incision ability matches that of land uplift due to tectonic forces. Superimposed drainage develops differently: initially,

2496-415: 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

2548-477: 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

2600-420: The topography of land, whether a particular region is dominated by hard or soft rocks, and the gradient of the land. Geomorphologists and hydrologists often view streams as part of drainage basins (and sub-basins ). This is the topographic region from which a stream receives runoff , throughflow , and its saturated equivalent, groundwater flow . The number, size, and shape of the drainage basins varies and

2652-427: The valley by conglomerate and sandstone. There are also a few beds of limestone and many limestone concretions. Except for a small area of sandstone near the big bend the numerous bedrock exposures along the creek are shale or the intruded dikes. The gravel deposits of Young Creek are of three classes—highbench gravels, which lie well above the stream levels and form in part the canyon wall; low-bench gravels, which adjoin

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2704-641: 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

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