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101-513: The river's drainage basin covers an area of 3,150 square kilometres (1,220 sq mi), and its mean annual flow is 21.7 cubic metres per second (770 cu ft/s). 30°24′46″S 59°34′47″W  /  30.41278°S 59.57972°W  / -30.41278; -59.57972 This article about a place in Corrientes Province , Argentina is a stub . You can help Misplaced Pages by expanding it . This article about

202-476: A lake or ocean . A basin 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

303-484: 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

404-414: 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

505-454: 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

606-540: 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

707-472: A fragile ecosystem known as the Southern Appalachian spruce–fir forest . Fraser fir rarely occurs below 5,500 ft (1,700 m), and becomes the dominant tree type at 6,200 ft (1,900 m). By contrast, balsam fir is found from near sea level to the tree line in the northern Appalachians, but ranges only as far south as Virginia and West Virginia in the central Appalachians, where it

808-735: A great thickness of sediment accumulated. Eventually, the tectonic forces pulling the two continents apart became so strong that an ocean formed off the eastern coast of the Laurentian margin. This was called the Iapetus Ocean and was the precursor of the modern Atlantic Ocean. The rocks of the Valley and Ridge province formed over millions of years, in the Iapetus. Shells and other hard parts of ancient marine plants and animals accumulated to form limey deposits that later became limestone. This

909-672: A new ocean opened up, the Rheic Ocean , during the Middle to Late Devonian, and subsequently its closure would result in the formation of the Alleghanian orogeny . As the continental plates moved closer together, fragments of oceanic crust, islands, and other continental masses collided with the eastern margin of ancestral North America. By this time, plants had appeared on land, followed by scorpions, insects, and amphibians. The ocean continued to shrink until, about 270 million years ago,

1010-504: A number of deciduous rhododendrons (azaleas), and smaller heaths such as teaberry ( Gaultheria procumbens ) and trailing arbutus ( Epigaea repens ). The evergreen great rhododendron ( Rhododendron maximum ) is characteristic of moist stream valleys. These occurrences are in line with the prevailing acidic character of most oak forest soils. In contrast, the much rarer chinquapin oak ( Quercus muehlenbergii ) demands alkaline soils and generally grows where limestone rock

1111-444: A number of serious insect and disease outbreaks. Among the most conspicuous is that of the introduced spongy moth ( Lymantria dispar ), which infests primarily oaks, causing severe defoliation and tree mortality. But it also has the benefit of eliminating weak individuals, and thus improving the genetic stock, as well as creating rich habitat of a type through accumulation of dead wood. Because hardwoods sprout so readily, this moth

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1212-532: A place in Entre Ríos Province , Argentina is a stub . You can help Misplaced Pages by expanding it . This article related to a river in Argentina is a stub . You can help Misplaced Pages by expanding it . 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

1313-544: A variety of oaks ( Quercus spp.), hickories ( Carya spp.) and, in the past, by the American chestnut ( Castanea dentata ). The American chestnut was virtually eliminated as a canopy species by the introduced fungal chestnut blight ( Cryphonectaria parasitica ), but lives on as sapling-sized sprouts that originate from roots, which are not killed by the fungus. In present-day forest canopies, chestnut has been largely replaced by oaks. The oak forests of

1414-672: Is "section". The Appalachian Uplands are one of the seven physiographic divisions in Canada . Canada's GSC does not use the same classification system as the USGS below the division level. The agency does break the divisions of the Appalachian Uplands into 13 subsections that are in four different political provinces of Canada. While the Appalachian Highlands and Appalachian Uplands are generally continuous across

1515-709: Is a 2,175-mile (3,500 km) hiking trail that runs all the way from Mount Katahdin in Maine to Springer Mountain in Georgia , passing over or past a large part of the Appalachian range. The International Appalachian Trail is an extension of this hiking trail into the Canadian portion of the Appalachian range in New Brunswick and Quebec . While exploring inland along the northern coast of Florida in 1528,

1616-483: Is a boreal species that forms a few high elevation outliers as far south as West Virginia. All of these species except white pine tend to occupy sandy, rocky, poor soil sites, which are mostly acidic in character. White pine, a large species valued for its timber, tends to do best in rich, moist soil, either acidic or alkaline in character. Pitch pine is also at home in acidic, boggy soil, and Table Mountain pine may occasionally be found in this habitat as well. Shortleaf pine

1717-403: Is found at high elevations in the northern Appalachians, and in bogs as far south as Pennsylvania. The Appalachians are also home to two species of fir, the boreal balsam fir ( Abies balsamea ), and the southern high elevation endemic, Fraser fir ( Abies fraseri ). Fraser fir is endemic to the highest parts of the southern Appalachian Mountains, where along with red spruce it forms

1818-533: Is generally found in warmer habitats and at lower elevations than the other species. All the species listed do best in open or lightly shaded habitats, although white pine also thrives in shady coves, valleys, and on floodplains. The Appalachians are characterized by a wealth of large, beautiful deciduous broadleaf (hardwood) trees. Their occurrences are best summarized and described in E. Lucy Braun 's 1950 classic, Deciduous Forests of Eastern North America (Macmillan, New York). The most diverse and richest forests are

1919-414: Is near the surface. Hence no ericaceous shrubs are associated with it. The Appalachian flora also include a diverse assemblage of bryophytes (mosses and liverworts), as well as fungi . Some species are rare and/or endemic. As with vascular plants , these tend to be closely related to the character of the soils and the thermal environment in which they are found. Eastern deciduous forests are subject to

2020-465: Is not as harmful as the hemlock woolly adelgid . Perhaps more serious is the introduced beech bark disease complex, which includes both a scale insect ( Cryptococcus fagisuga ) and fungal components. During the 19th and early 20th centuries, the Appalachian forests were subject to severe and destructive logging and land clearing, which resulted in the designation of the national forests and parks as well many state-protected areas. However, these and

2121-527: Is now the southern United States, the Ococee Basin was formed. Seawater filled the basin. Rivers from the surrounding countryside carried clay, silt, sand, and gravel to the basin, much as rivers today carry sediment from the midcontinent region to the Gulf of Mexico. The sediment spread out in layers on the basin floor. The basin continued to subside, and over a long period of time, probably millions of years,

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2222-606: Is one of the provinces of the Appalachian Highlands. The Appalachian range runs from the Island of Newfoundland in Canada, 2,050 mi (3,300 km) southwestward to Central Alabama in the United States; south of Newfoundland, it crosses the 96-square-mile (248.6 km ) archipelago of Saint Pierre and Miquelon , an overseas collectivity of France , meaning it is technically in three countries. The highest peak of

2323-552: Is possible that the cratons of Kalahari , and Rio Plato , were also part of that early collision since they were present as Rodinia broke up). Mountain-building referred to as the Grenville Orogeny occurred along the boundaries of the cratons. The present Appalachian Mountains have at least two areas which are made from rock formations that were formed during this orogeny - the Blue Ridge Mountains and

2424-487: Is present today. The Appalachian Mountains are a barrier to east–west travel, as they form a series of alternating ridgelines and valleys oriented in opposition to most highways and railroads running east–west. This barrier was extremely important in shaping the expansion of the United States in the colonial era. The range is the home of a very popular recreational feature, the Appalachian Trail . This

2525-487: 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

2626-706: Is subject to the hemlock woolly adelgid ( Adelges tsugae ), an introduced insect, that is rapidly extirpating it as a forest tree. Less abundant, and restricted to the southern Appalachians, is Carolina hemlock ( Tsuga caroliniana ). Like Canada hemlock, this tree suffers severely from the hemlock woolly adelgid. Several species of pines characteristic of the Appalachians are eastern white pine ( Pinus strobus ), Virginia pine ( Pinus virginiana ), pitch pine ( Pinus rigida ), Table Mountain pine ( Pinus pungens ) and shortleaf pine ( Pinus echinata ). Red pine ( Pinus resinosa )

2727-614: 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

2828-506: Is the same process by which limestone forms in modern oceans. The weathering of limestone, now exposed at the land surface, produces the lime-rich soils that are so prevalent in the fertile farmland of the Valley and Ridge province. During this continental break-up, around 600 million to 560 million years ago, volcanic activity was present along the tectonic margins. There is evidence of this activity in today's Blue Ridge Mountains. Mount Rogers , Whitetop Mountain , and Pine Mountain are all

2929-464: Is usually confined above 3,900 ft (1,200 m) asl, except in cold valleys. Curiously, it is associated with oaks in Virginia. The balsam fir of Virginia and West Virginia is thought by some to be a natural hybrid between the more northern variety and Fraser fir. While red spruce is common in both upland and bog habitats, balsam fir, as well as black spruce and tamarack, are more characteristic of

3030-628: The Adirondacks . After the Grenville orogeny, the direction of the continental drift reversed, and the single supercontinent Rodinia began to break up. The mountains formed during the Grenvillian era underwent erosion due to weathering, glaciation, and other natural processes, resulting in the leveling of the landscape. The eroded sediments from these mountains contributed to the formation of sedimentary basins and valleys. For example, in what

3131-713: 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

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3232-596: The Coal Region of northeastern Pennsylvania . The bituminous coal fields of western Pennsylvania , western Maryland , southeastern Ohio, eastern Kentucky, southwestern Virginia , and West Virginia contain the sedimentary form of coal. The mountain top removal method of coal mining , in which entire mountain tops are removed, is currently threatening vast areas and ecosystems of the Appalachian Mountain region. The surface coal mining that started in

3333-765: 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,

3434-758: The Gulf of Mexico . In the central section, north of the New River, the rivers, rising in or just beyond the Valley Ridges, flow through great gorges to the Great Valley, and then across the Blue Ridge to tidal estuaries penetrating the coastal plain via the Roanoke River, James River , Potomac River , and Susquehanna River . In the northern section the height of land lies on the inland side of

3535-734: The Iapetus Ocean , from the North America/Europe collision (See Caledonian orogeny ). By the end of the Mesozoic Era , the Appalachian Mountains had been eroded to an almost flat plain. It was not until the region was uplifted during the Cenozoic Era that the distinctive topography of the present formed. Uplift rejuvenated the streams, which rapidly responded by cutting downward into the ancient bedrock. Some streams flowed along weak layers that define

3636-714: 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

3737-491: The North American craton . Volcanoes grew along the continental margin coincident with the initiation of subduction . Thrust faulting uplifted and warped older sedimentary rock laid down on the passive margin. As the mountains rose, erosion began to wear them down over time. Streams carried rock debris downslope to be deposited in nearby lowlands. The Taconic orogeny ended after about 60 million years, but built much of

3838-723: The eastern seaboard of the United States and the Midwest region of the country. The Eastern Continental Divide follows the Appalachian Mountains from Pennsylvania to Georgia. The Appalachians, particularly the Central and Southern regions, is one of the most biodiverse places in North America. The north–south orientation of the long ridges and valleys contributes to the high number of plant and animal species. Species were able to migrate through these from either direction during alternating periods of warming and cooling, settling in

3939-502: 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. Appalachian Mountains The Appalachian Mountains , often called the Appalachians , are a mountain range in eastern to northeastern North America . The term "Appalachian" refers to several different regions associated with

4040-1552: The mixed-mesophytic or medium-moisture types, which are largely confined to rich, moist montane soils of the southern and central Appalachians, particularly in the Cumberland and Allegheny Mountains, but also thrive in the southern Appalachian coves. Characteristic canopy species are white basswood ( Tilia heterophylla ), yellow buckeye ( Aesculus octandra ), sugar maple ( Acer saccharum ), American beech ( Fagus grandifolia ), tuliptree ( Liriodendron tulipifera ), white ash ( Fraxinus americana ) and yellow birch ( Betula alleganiensis ). Other common trees are red maple ( Acer rubrum ), shagbark and bitternut hickories ( Carya ovata and C. cordiformis ) and black or sweet birch ( Betula lenta ). Small understory trees and shrubs include paw paw ( Asimina tribola ), flowering dogwood ( Cornus florida ), hophornbeam ( Ostrya virginiana ), witch-hazel ( Hamamelis virginiana ) and spicebush ( Lindera benzoin ). There are also hundreds of perennial and annual herbs, among them such herbal and medicinal plants as American ginseng ( Panax quinquefolius ), goldenseal ( Hydrastis canadensis ), bloodroot ( Sanguinaria canadensis ) and black cohosh ( Cimicifuga racemosa ). The foregoing trees, shrubs, and herbs are also more widely distributed in less rich mesic forests that generally occupy coves, stream valleys and flood plains throughout

4141-596: The 1940s has significantly impacted the central Appalachian Mountains in Kentucky , Tennessee , Virginia and West Virginia. Early mining methods were unregulated and mined land reclamation research, including acid base reaction , was led by the West Virginia University in the 1960s and 1970s. West Virginia developed rigorous mine reclamation standards for state coal mines in the late 1960s. Regulations were introduced by most federal states to protect

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4242-564: The Appalachian Basin. Some plateaus of the Appalachian Mountains contain metallic minerals such as iron and zinc . There are many geological issues concerning the rivers and streams of the Appalachians. In spite of the existence of the Great Appalachian Valley, many of the main rivers are transverse to the mountain system axis. The drainage divide of the Appalachians follows a tortuous course that crosses

4343-627: The Appalachian Mountains by the late 1960s. Social and political activism brought about the Surface Mining Control and Reclamation Act of 1977 . The 1859 discovery of commercial quantities of petroleum in the Appalachian Mountains of western Pennsylvania started the modern United States petroleum industry . Recent discoveries of commercial natural gas deposits in the Marcellus Shale formation and Utica Shale formations have once again focused oil industry attention on

4444-552: The Blue Ridge again reaches 2,000 ft (600 m) and higher. In the Virginia Blue Ridge, the following are some of the highest peaks north of the Roanoke River : Stony Man 4,031 ft (1,229 m), Hawksbill Mountain 4,066 ft (1,239 m), Apple Orchard Mountain 4,225 ft (1,288 m) and Peaks of Otter 4,001 and 3,875 ft (1,220 and 1,181 m). South of the Roanoke River, along

4545-738: The Blue Ridge, are Virginia's highest peaks including Whitetop Mountain 5,520 ft (1,680 m) and Mount Rogers 5,729 ft (1,746 m), the highest point in the Commonwealth. Chief summits in the southern section of the Blue Ridge are located along two main crests, the Western or Unaka Front along the Tennessee - North Carolina border and the Eastern Front in North Carolina, or one of several "cross ridges" between

4646-931: The Great Balsams. The Western Blue Ridge Front is subdivided into the Unaka Range , the Bald Mountains , the Great Smoky Mountains , and the Unicoi Mountains , and its major peaks include Roan Mountain 6,285 ft (1,916 m) in the Unakas, Big Bald 5,516 ft (1,681 m) and Max Patch 4,616 ft (1,407 m) in the Bald Mountains, Kuwohi 6,643 ft (2,025 m), Mount Le Conte 6,593 feet (2,010 m), and Mount Guyot 6,621 ft (2,018 m) in

4747-749: The Great Smokies, and Big Frog Mountain 4,224 ft (1,287 m) near the Tennessee- Georgia -North Carolina border. Prominent summits in the cross ridges include Waterrock Knob (6,292 ft (1,918 m)) in the Plott Balsams . Across northern Georgia, numerous peaks exceed 4,000 ft (1,200 m), including Brasstown Bald , the state's highest, at 4,784-and-4,696 ft (1,458-and-1,431 m) Rabun Bald . In north-central Alabama , Mount Cheaha rises prominently to 1,445 feet (440 m) over its surroundings, as part of

4848-521: The U.S./Canadian border, the St. Lawrence Valley area is handled differently in the physiographic classification schemas. The part of the St. Lawrence Valley in the United States is one of the second-level classifications, part of the Appalachian Highlands. In Canada, the area is part of the first-level classification, the St. Lawrence Lowlands . This includes the area around the city of Montreal, Anticosti Island , and

4949-623: 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

5050-457: The adjective Appalachian is / ˌ æ p ə ˈ l æ tʃ i ə n / , with the last two syllables "-ian" pronounced as in the word "Romanian". Perhaps partly because the range runs through large portions of both the United States and Canada, and partly because the range was formed over numerous geologic time periods, one of which is sometimes termed the Appalachian orogeny , writing communities struggle to agree on an encyclopedic definition of

5151-406: 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

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5252-457: The continent that are now exposed. The first mountain-building tectonic plate collision that initiated the construction of what are today the Appalachians occurred at least a billion years ago when the pre-North American craton called Laurentia collided with at least one other craton - Amazonia . All the other cratons of the earth also collided at about this time to form the supercontinent Rodinia and were surrounded by one single ocean. (It

5353-416: The continents that were ancestral to North America and Africa collided during the formation of the supercontinent Pangea . Because North America and Africa were once geographically connected, the Appalachians formed part of the same mountain chain as the Little Atlas in Morocco . This mountain range, known as the Central Pangean Mountains , extended into Scotland , before the Mesozoic Era opening of

5454-412: The deciduous needle-leaf conifer, the tamarack , or eastern larch ( Larix laricina ). The dominant northern and high elevation conifer is the red spruce ( Picea rubens ), which grows from near sea level to above 4,000 ft (1,200 m) above sea level (asl) in northern New England and southeastern Canada. It also grows southward along the Appalachian crest to the highest elevations of

5555-430: 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

5656-441: 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

5757-642: 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

5858-529: The driest sites are dominated by chestnut oak, or sometimes by scarlet or northern red oaks. In the northern Appalachians the oaks, except for white and northern red, drop out, while the latter extends farthest north. The oak forests generally lack the diverse small tree, shrub and herb layers of mesic forests. Shrubs are generally ericaceous , and include the evergreen mountain laurel ( Kalmia latifolia ), various species of blueberries ( Vaccinium spp.), black huckleberry ( Gaylussacia baccata ),

5959-432: 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

6060-440: The eight physiographic regions of the contiguous 48 United States. The Appalachian Uplands is the name of one of seven physiographic regions of Canada. The second level in the physiographic classification schema for the USGS is "province", the same word as Canada uses to divide its political subdivisions, meaning that the terminology used by the two countries do not match below the region level. The lowest level of classification

6161-425: The folds and faults created many millions of years earlier. Other streams downcut so rapidly that they cut right across the resistant folded rocks of the mountain core, carving canyons across rock layers and geologic structures. The Appalachian Mountains contain major deposits of anthracite coal as well as bituminous coal . In the folded mountains the coal is in metamorphosed form as anthracite , represented by

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6262-443: The formation of the Appalachian Mountains started 1.1 billion years ago. The first mountain range in the region was created when the continents of Laurentia and Amazonia collided, creating a supercontinent called Rodinia . The collision of these continents caused the rocks to be folded and faulted, creating the first mountains in the region. Many of the rocks and minerals that were formed during that event can currently be seen at

6363-412: 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 ,

6464-435: 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

6565-422: 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

6666-417: 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

6767-431: The land mass that is now New England and southwestward to Pennsylvania. The Taconic Orogeny was the second of four mountain building plate collisions that contributed to the formation of the Appalachians, culminating in the collision of North America and Africa (see Alleghanian orogeny ). The third mountain-building event was the Acadian orogeny which occurred between 375 and 359 million years ago. The Acadian orogeny

6868-469: The latter. However, balsam fir also does well in soils with a pH as high as 6. Eastern or Canada hemlock ( Tsuga canadensis ) is another important evergreen needle-leaf conifer that grows along the Appalachian chain from north to south but is confined to lower elevations than red spruce and the firs. It generally occupies richer and less acidic soils than the spruce and firs and is characteristic of deep, shaded and moist mountain valleys and coves . It

6969-473: The members of the Narváez expedition , including Álvar Núñez Cabeza de Vaca , found a Native American village near present-day Tallahassee, Florida whose name they transcribed as Apalchen or Apalachen [a.paˈla.tʃɛn] . The name was soon altered by the Spanish to Apalachee and used as a name for the tribe and region spreading well inland to the north. Pánfilo de Narváez 's expedition first entered Apalachee territory on June 15, 1528, and applied

7070-456: The microclimates that best suited them. The flora of the Appalachians are diverse and vary primarily in response to geology, latitude, elevation and moisture availability. Geobotanically, they constitute a floristic province of the North American Atlantic Region . The Appalachians consist primarily of deciduous broad-leaf trees and evergreen needle-leaf conifers, but also contain the evergreen broad-leaf American holly ( Ilex opaca ), and

7171-433: The more notable peaks in West Virginia. The Blue Ridge Mountains , rising in southern Pennsylvania and there known as South Mountain , attain elevations of about 2,000 ft (600 m) in Pennsylvania. South Mountain achieves its highest point just below the Mason-Dixon line in Maryland at Quirauk Mountain 2,145 ft (654 m) and then diminishes in height southward to the Potomac River . Once in Virginia ,

7272-514: 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

7373-666: The mountain range is Mount Mitchell in North Carolina at 6,684 feet (2,037 m), which is also the highest point in the United States east of the Mississippi River . The range is older than the other major mountain range in North America, the Rocky Mountains of the west. Some of the outcrops in the Appalachians contain rocks formed during the Precambrian era. The geologic processes that led to

7474-637: The mountain range, and its surrounding terrain. The general definition used is one followed by the United States Geological Survey and the Geological Survey of Canada to describe the respective countries' physiographic regions. The U.S. uses the term Appalachian Highlands and Canada uses the term Appalachian Uplands ; the Appalachian Mountains are not synonymous with the Appalachian Plateau , which

7575-410: The mountain range. However, each of the governments has an agency that informs the public about the major landforms that make up the countries, the United States Geological Survey (USGS) and the Geological Survey of Canada (GSC). The landforms are referred to as physiographic regions. The regions create precise boundaries from which maps can be drawn. The Appalachian Highlands is the name of one of

7676-787: The mountainous belt just north of the New River in Virginia. South of the New River, rivers head into the Blue Ridge, cross the higher Unakas, receive important tributaries from the Great Valley, and traversing the Cumberland Plateau in spreading gorges ( water gaps ), escape by way of the Cumberland River and the Tennessee River rivers to the Ohio River and the Mississippi River, and thence to

7777-550: The mountainous belt, and thus the main lines of drainage run from north to south, exemplified by the Hudson River . However, the valley through which the Hudson River flows was cut by the gigantic glaciers of the ice ages —the same glaciers that deposited their terminal moraines in southern New York and formed the east–west Long Island . The Appalachian region is generally considered the geographical divide between

7878-430: The name. Now spelled "Appalachian", it is the fourth-oldest surviving European place-name in the US. After the 1540 expedition of Hernando de Soto , Spanish cartographers began to apply the name of the tribe to the mountains themselves. The first cartographic appearance of Apalchen is on Diego Gutiérrez 's map of 1562; the first use for the mountain range is the map of Jacques le Moyne de Morgues in 1565. The name

7979-531: The northwest coastline of Newfoundland. The dissected plateau area, while not actually made up of geological mountains, is popularly called "mountains", especially in eastern Kentucky and West Virginia, and while the ridges are not high, the terrain is extremely rugged. In Ohio and New York, some of the plateau has been glaciated , which has rounded off the sharp ridges and filled the valleys to some extent. The glaciated regions are usually referred to as hill country rather than mountains. The Appalachian belt includes

8080-424: The oceans, but there were no plants or animals on land. Then, during the middle Ordovician Period about 500 to 470 million years ago, the motion of the crustal plates changed, and the continents began to move back toward each other. The once-quiet Appalachian passive margin changed to a very active plate boundary when a neighboring Iapetus oceanic plate containing a volcanic arc collided with and began sinking beneath

8181-738: The plateaus sloping southward to the Atlantic Ocean in New England , and southeastward to the border of the coastal plain through the central and southern Atlantic states; and on the northwest, the Allegheny and Cumberland plateaus declining toward the Great Lakes and the interior plains. A remarkable feature of the belt is the longitudinal chain of broad valleys, including the Great Appalachian Valley , which in

8282-418: 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

8383-631: 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

8484-488: The result of volcanic activity that occurred around this time. Evidence of subsurface activity, dikes and sills intruding into the overlying rock, is present in the Blue Ridge as well. For instance, mafic rocks have been found along the Fries Fault in the central Blue Ridge area of Montgomery County, VA. The Iapetus continued to expand and during that time bacteria, algae, and many species of invertebrates flourished in

8585-461: 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

8686-725: The same side of the Great Valley, south of the Potomac, are the Pinnacle 3,007 feet (917 m) and Pidgeon Roost 3,400 ft (1,000 m). In West Virginia, more than 150 peaks rise above 4,000 ft (1,200 m), including Spruce Knob 4,863 ft (1,482 m), the highest point in the Allegheny Mountains . A number of other points in the state rise above 4,800 ft (1,500 m). Cheat Mountain ( Snowshoe Mountain ) at Thorny Flat 4,848 ft (1,478 m) and Bald Knob 4,842 ft (1,476 m) are among

8787-409: The same trend as the system itself. None of the summits reaches the region of perpetual snow. In Pennsylvania , there are over sixty summits that rise over 2,500 ft (800 m); the summits of Mount Davis and Blue Knob rise over 3,000 ft (900 m). In Maryland, Eagle Rock and Dans Mountain are conspicuous points reaching 3,162 and 2,882 ft (964 and 878 m) respectively. On

8888-487: The southerly sections divides the mountain system into two unequal portions, but in the northernmost lies west of all the ranges possessing typical Appalachian features, and separates them from the Adirondack group. The mountain system has no axis of dominating altitudes, but in every portion, the summits rise to rather uniform heights, and, especially in the central section, the various ridges and intermontane valleys have

8989-416: The southern Appalachians, as in North Carolina and Tennessee . In the central Appalachians it is usually confined above 3,000 ft (900 m) asl, except for a few cold valleys in which it reaches lower elevations. In the southern Appalachians, it is restricted to higher elevations. Another species is the black spruce ( Picea mariana ), which extends farthest north of any conifer in North America,

9090-413: The southern and central Appalachians consist largely of black , northern red , white , chestnut and scarlet oaks ( Quercus velutina, Q. rubra, Q. alba, Q. prinus and Q. coccinea ) and hickories, such as the pignut ( Carya glabra ) in particular. The richest forests, which grade into mesic types, usually in coves and on gentle slopes, have predominantly white and northern red oaks, while

9191-511: The southern and central Appalachians at low and intermediate elevations. In the northern Appalachians and at higher elevations of the central and southern Appalachians these diverse mesic forests give way to less diverse northern hardwood forests with canopies dominated only by American beech, sugar maple, American basswood ( Tilia americana ) and yellow birch and with far fewer species of shrubs and herbs. Drier and rockier uplands and ridges are occupied by oak–chestnut forests dominated by

9292-544: The southernmost spur of the Blue Ridge Mountains. Sources written prior to the recognition of the concept of physiographic regions divided the Appalachian Mountains into three major sections: Plate tectonics over the period dating back at least 1 billion years led to geological creation of the land that is now the Appalachian Mountain range. The continental movement led to collisions that built mountains and they later pulled apart creating oceans over parts of

9393-418: 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

9494-504: The surface of the present Appalachian range. Around 480 million years ago, geologic processes began that led to three distinct orogenic eras that created much of the surface structure seen in today's Appalachians. During this period, mountains once reached elevations similar to those of the Alps and the Rockies before natural erosion occurred over the last 240 million years leading to what

9595-411: The third syllable sounding like "latch". In northern parts of the mountain range, it is pronounced / ˌ æ p ə ˈ l eɪ tʃ ɪ n z / or / ˌ æ p ə ˈ l eɪ ʃ ɪ n z / ; the third syllable is like "lay", and the fourth "chins" or "shins". There is often great debate between the residents of the regions regarding the correct pronunciation. Elsewhere, a commonly accepted pronunciation for

9696-415: 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

9797-477: 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

9898-628: The two main crests. Major subranges of the Eastern Front include the Black Mountains , Great Craggy Mountains , and Great Balsam Mountains , and its chief summits include Grandfather Mountain 5,964 ft (1,818 m) near the Tennessee-North Carolina border, Mount Mitchell 6,684 ft (2,037 m) in the Blacks, and Black Balsam Knob 6,214 ft (1,894 m) and Cold Mountain 6,030 ft (1,840 m) in

9999-666: 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

10100-661: Was caused by a series of collisions of pieces of crust from the Avalonia Terrane, sections broken off from continent of Gondwana , with the North American Plate. The collision initiating this orogeny resulted in the closing of the southern Iapetus Ocean and the formation of a high mountain belt. After the Acadian collision took place, Gondwana began to retreat from Laurentia with the newly accreted Avalonian terranes left behind. As Gondwana moved away,

10201-442: Was not commonly used for the whole mountain range until the late 19th century. A competing and often more popular name was the "Allegheny Mountains", "Alleghenies", and even "Alleghania". In the early 19th century, Washington Irving proposed renaming the United States either Appalachia or Alleghania. In U.S. dialects in the southern regions of the Appalachians, the word is pronounced / ˌ æ p ə ˈ l æ tʃ ɪ n z / , with

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