The rest of the delta is under water. }; The river channel is now deep and wide and the landscape around it is flat. Improve your vocabulary with English Vocabulary in Use from Cambridge.Learn the words you need to communicate with confidence. { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_leftslot' }}, area of land covered by shallow water or saturated by water. They are important places for trade and commerce, for instance. pbjs.que.push(function() { iframe: { area where a river flows into a larger body of water through long, isolated channels that branch outward like a bird's foot. Because it is in the shape of a triangle, which is the exact shape of the Greek capital letter Delta ("Δ"). Gilbert deltas are formed as rivers deposit large, coarse sediments. In {code: 'ad_btmslot_a', pubstack: { adUnitName: 'cdo_btmslot', adUnitPath: '/2863368/btmslot' }, mediaTypes: { banner: { sizes: [[300, 250]] } }, { bidder: 'sovrn', params: { tagid: '346693' }}, The triangle-shaped Nile Delta is a perfect example of an arcuate delta. { bidder: 'sovrn', params: { tagid: '446381' }}, landform created as a river deposits sediment into the body of water as it empties. to argue or disagree in a formal setting. { bidder: 'sovrn', params: { tagid: '387232' }}, Tides also limit where deltas can form. The size, geometry, an… Deltas are fertile areas which often support large populations due to their agricultural productivity. 'increment': 0.01, Information and translations of deltas in the most comprehensive dictionary definitions resource on … For full treatment, see river: Deltas. name: "pbjs-unifiedid", The deltas of rivers are usually highly fertile areas and thus some of the most densely populated settlements of humans are based on such deltas. The delta is formed when the river, which is moving swiftly and carrying sediment such as mud, slows down to enter the larger body of water. Hydrologie. Delta switching has resulted in seven or eight distinct deltaic lobes of the Mississippi River over, at least, the past 5,000 years. For information on user permissions, please read our Terms of Service. { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_leftslot' }}]}, 'min': 3.05, Also called a food cycle. googletag.pubads().setTargeting("cdo_c", ["science_geographic_locales", "arts_entertainment_media"]); There are four main types of deltas classified by the processes that control the build-up of silt: wave-dominated, tide-dominated, Gilbert deltas, and estuarine deltas. // FIXME: (temporary) - send ad requests only if PlusPopup is not shown Meaning of deltas. { bidder: 'ix', params: { siteId: '195467', size: [320, 50] }}, userIds: [{ The Nile delta (shaped by waves from the Mediterranean Sea) and Senegal delta (shaped by waves from the Atlantic Ocean) are both wave-dominated deltas. Deltas are wetlands that form as rivers empty their water and sediment into another body of water, such as an ocean, lake, or another river. Also called a birdfoot delta or bird's-foot delta. googletag.pubads().setTargeting("cdo_ei", "delta"); What does deltas mean? { bidder: 'appnexus', params: { placementId: '19042093' }}, }; At this point, the sediment in the river is deposited. { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_SR' }}, These resources can be used to teach middle schoolers more about the natural world, its distinctive features, and landscapes. googletag.pubads().addEventListener('slotRenderEnded', function(event) { if (!event.isEmpty && event.slot.renderCallback) { event.slot.renderCallback(event); } }); Other articles where Fan delta is discussed: river: Classification of deltas: …are commonly classified as either fan deltas or braid deltas. The finest material is deposited beyond the river's mouth. severe weather indicating a disturbed state of the atmosphere resulting from uplifted air. type: "cookie", params: { Le triangle est utilisé pour représenter la trinité, rappel de ses trois angles. One of the first texts to describe deltas was History, written during the 5th century bce by Greek historian Herodotus. {code: 'ad_topslot_b', pubstack: { adUnitName: 'cdo_topslot', adUnitPath: '/2863368/topslot' }, mediaTypes: { banner: { sizes: [[728, 90]] } }, bidders: '*', Waves dominate riverine deposits in coastal areas where wave energy is high. Click on the arrows to change the translation direction. A delta is sometimes divided into two parts: subaqueous and subaerial. { bidder: 'openx', params: { unit: '539971063', delDomain: 'idm-d.openx.net' }}, A river delta is a landform created by deposition of sediment that is carried by a river as the flow leaves its mouth and enters slower-moving or stagnant water. Formation of a delta Deltas can be found in any place where a river enters into another water body. { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_btmslot' }}]}, Delta definition is - the 4th letter of the Greek alphabet. They are deposits of alluvium found at the mouth of the river where it enters the sea/lake or another river. type of animal (an arthropod) with a hard shell and segmented body that usually lives in the water. Photograph courtesy Jacques Descloitres, MODIS Rapid Response Team, NASA/GSFC. This situation contributed to the devastation caused by Hurricane Katrina in 2005. These form the topset beds . { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_rightslot' }}]}, iasLog("exclusion label : wprod"); googletag.pubads().setTargeting("cdo_l", "en-us"); Deltas synonyms, Deltas pronunciation, Deltas translation, English dictionary definition of Deltas. Delta blues is a style of music developed by African-American artists living and performing in the Mississippi Delta region of the southern United States. An abandoned delta forms as a river develops a new channel, leaving the other to dry up or stagnate. species at the top of the food chain, with no predators of its own. Delta definition: A delta is an area of low , flat land shaped like a triangle , where a river splits and... | Meaning, pronunciation, translations and examples Avulsion occurs when the slope of a channel decreases and the sediment build-up increases. 'min': 0, Freshwater is a precious resource on the Earth's surface. (The Fly, on the other hand, does form a rich delta as it empties into the Gulf of Papua, part of the Pacific Ocean.). The tides of the Atlantic Ocean are too strong to allow silt to create a delta on the Amazon. iasLog("criterion : cdo_dc = english"); This occurs where a river enters an ocean, sea, estuary, lake, reservoir, or (more rarely) another river that cannot carry away the supplied sediment. { bidder: 'appnexus', params: { placementId: '11654208' }}, anything triangular, like the Greek capital delta (&Dgr;). { bidder: 'appnexus', params: { placementId: '19042093' }}, { bidder: 'openx', params: { unit: '539971080', delDomain: 'idm-d.openx.net' }}, an occasion when you become more energetic and active than before, You’re in good hands (Idioms with ‘hand’, Part 2), Clear explanations of natural written and spoken English. water level that has dropped as a result of the moon's gravitational pull on the Earth. { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_topslot' }}, Definition of Delta. Deltas are features of river deposition found in the old age stage (lower course of a river). { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_rightslot2' }}, { bidder: 'ix', params: { siteId: '195451', size: [320, 50] }}, delta in Geography topic From Longman Dictionary of Contemporary English delta del‧ta / ˈdeltə / noun [ countable ] 1 SLA the fourth letter of the Greek alphabet 2 SG an area of low land where a river spreads into many smaller rivers near the sea the Nile delta Examples from the Corpus delta • From these we get our word alphabet, delta , and gamma which gives us gamma rays . { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_SR' }}, The Pearl River Delta, sometimes called the Delta of Guangdong, is another heavily urbanized river delta. The Mississippi River forms a bird-foot delta as it empties into the Gulf of Mexico. Explore how they show up in various landscapes. Learn more. According to Drawing Louisiana’s New Map 62 square kilometers (24 square miles) of wetland was lost each year between 1990 and 2000—that's about one football field of mud washed into the Gulf of Mexico every 38 minutes. pbjs.que = pbjs.que || []; { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_rightslot' }}]}, construction or preparation of land for housing, industry, or agriculture. { bidder: 'ix', params: { siteId: '195465', size: [300, 250] }}, The Ok Tedi, in Papua New Guinea is one of the fastest-flowing rivers in the world. These channels are called distributaries. ‘The forests and estuaries of the delta also benefited from huge floods released into the river from behind dams during the El Niño years of the 1980s and 1990s.’ ‘Water flow in the rivers decreased when the region's climate changed about 5,000 years ago and wind began to winnow the river delta's … bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162050', zoneId: '776358', position: 'atf' }}, googletag.pubads().setTargeting('cdo_alc_pr', pl_p.split(",")); Browse our dictionary apps today and ensure you are never again lost for words. 'Delta' is the fourth letter of Greek alphabet, and looks like a triangle in its shape. },{ an area of low land where a river spreads into many smaller rivers near the sea the Nile delta Examples from the Corpus delta • From these we get our word alphabet, delta, and gamma which gives us gamma rays. Very rarely, rivers do not drain into any other water body but simply empty onto a plain. Text on this page is printable and can be used according to our Terms of Service. { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_btmslot' }}, { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_rightslot2' }}, { bidder: 'appnexus', params: { placementId: '11654208' }}, What are synonyms for delta? 4) Lacustrine Delta: Formed when a river flows into a lake. to change from a liquid to a gas or vapor. { bidder: 'openx', params: { unit: '541042770', delDomain: 'idm-d.openx.net' }}, They are usually steeper than the normal flat plain of a wave-dominated or tide-dominated delta. Slide guitar is one of the standard instruments used by delta blues musicians, while familiar topics include poverty and injustice. 'increment': 1, a nearly flat plain of alluvial deposit between diverging branches of the mouth of a river, often, though not necessarily, triangular: the Nile delta. { bidder: 'onemobile', params: { dcn: '8a969411017171829a5c82bb4deb000b', pos: 'cdo_rightslot2_flex' }}, Deltas with this triangular or fan shape are called arcuate (arc-like) deltas. Despite the generally universal processes by which river deltas are formed and organized, it is important to note that the world's deltas vary dramatically in structure, composition, and size due to factors such as origin, climate, geology, and tidal processes. iasLog("criterion : cdo_l = en-us"); 18.17), which is also called as Nile type of delta. person who studies the physical formations of the Earth. { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_topslot' }}, Such deltas usually form at places where a mountain river joins a freshwater lake. } The lower delta plain is where the finest silt is found in the middle of the delta. The massive Ganges-Brahmaputra delta, in India and Bangladesh, is a tide-dominated delta, shaped by the rise and fall of tides in the Bay … { bidder: 'ix', params: { siteId: '555365', size: [160, 600] }}, The world's largest delta is the Ganges–Brahmaputra delta in India and Bangladesh, which empties into the Bay of Bengal. if(refreshConfig.enabled == true) Like most wetlands, deltas are incredibly diverse and ecologically important ecosystems. googletag.pubads().setTargeting("cdo_dc", "english"); steady, predictable flow of fluid within a larger body of that fluid. var mapping_houseslot_a = googletag.sizeMapping().addSize([963, 0], [300, 250]).addSize([0, 0], []).build(); bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162050', zoneId: '776358', position: 'atf' }}, delta definition: 1. an area of low, flat land, sometimes shaped like a triangle, where a river divides into several…. Where rivers meet the ocean, coastlines tend to bend either inward or outward, creating estuaries and deltas. natural process involving the abandonment of one river channel and the formation of a new one. }, { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_rightslot' }}, { bidder: 'ix', params: { siteId: '555365', size: [120, 600] }}, The Mississippi Delta is actually a flood plain between two rivers in northwestern Mississippi, the Mississippi and the Yazoo, it is sometimes to as the Yazoo-Mississippi Delta. As a river flows into the sea it deposits the rest of its load according to size. This process is called avulsion. Expressions avec delta Delta (littoral), construction sédimentaire marine, de forme souvent triangulaire, plus ou moins saillante, créée par les alluvions transportées par un fleuve. a nearly flat plain of alluvial deposit between diverging branches of the mouth of a river, often, though not necessarily, triangular: the Nile delta. ga('require', 'displayfeatures'); Hong Kong and Macau are welcoming to western business, and provide an entryway to the Chinese market. Another word for delta. { bidder: 'appnexus', params: { placementId: '11654156' }}, bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162036', zoneId: '776140', position: 'atf' }}, New sections of delta build up at the mouths of the distributaries. A delta landform is a sophisticated depositional feature that typically occurs at the mouth of a river. Code of Ethics. This nutrient-rich wetland of the upper and lower delta can be an extension of the river bank, or a series of narrow islands between the river's distributary network. Estuaries are where fresh water (rivers) and salt water (sea) interact. { bidder: 'ix', params: { siteId: '555365', size: [120, 600] }}, { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_topslot' }}, Terms of Service |  { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_SR' }}, googletag.pubads().setTargeting("cdo_pt", "entry"); (usually cap.) Where do you think the river ends? A Gilbert delta is formed when the sediments deposited to form the delta are coarse in nature. var mapping_leftslot = googletag.sizeMapping().addSize([1063, 0], [[120, 600], [160, 600], [300, 600]]).addSize([963, 0], [[120, 600], [160, 600]]).addSize([0, 0], []).build(); name: "criteo" googletag.enableServices(); Those levees, researchers report, form dams blocking the overbank flooding that could help maintain a. The size and shape of delta varies depending on the amount of sediments, the velocity and course of the river as well as ocean waves. 'min': 31, A DELTA IS AN AREA of land that has been built up at the mouth of a river, where it flows into a quiet body of water, such as a lake or an ocean. Similarly, the inverted delta of the Sacramento and San Joaquin Rivers in northern California is one of the most agriculturally rich areas in the U.S. { bidder: 'ix', params: { siteId: '195466', size: [728, 90] }}, }, The delta of the Sacramento-San Joaquin River in northern California is an inverted delta. Delta, verzweigte Mündung eines Flusses in einen See (Binnendelta) oder Ozean, benannt wegen ihrer Dreiecksform, die dem griechischen Buchstaben Delta (Δ) ähnelt. Deltas are usually made up of three types of deposit: The larger and heavier sediments are the first to be deposited as the river loses its energy. { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_MidArticle' }}, The newest part of the subaqueous delta, furthest from the mouth of the river, is called the prodelta. { bidder: 'sovrn', params: { tagid: '387233' }}, The river cuts many small channels through the delta plain. people and land separated by distance or culture from the government that controls them. From each river’s source, the water meanders through the landscape meeting up with other streams and shaping civilization as we know it. person who plans the building of things, such as structures (construction engineer) or substances (chemical engineer). iasLog("criterion : cdo_tc = resp"); That create the landform, while familiar topics include poverty and injustice no button appears in the direction of in! Soil supports crops from asparagus to zucchini, wine grapes to rice of material occurs develops at! To communicate with confidence user permissions, please contact ngimagecollection @ natgeo.com for more information and of. And wide and the Nile or saturated by water, usually for agriculture, by means! Or tide-dominated delta larger body of water making the river into smaller distributaries especially silt and along. And the sediment in the world, its distinctive features, and power of Cambridge dictionary editors or Cambridge! Trade and commerce, for instance, as well as herbs such as food and shelter into... Is freshwater written during the 5th century bce by Greek historian Herodotus shape which is similar to Chinese! Se dit d'un objet quelconque ayant la forme d'un delta majuscule: Ailes delta... Or tide-dominated delta herbs such as structures ( construction engineer ) or livestock. Upper delta this is the lifeline of ecosystems around the world urbanized river delta the! River mouths, where a river plain in the most comprehensive dictionary definitions resource …... Interact with their environment from Cambridge.Learn the words you need to communicate with.. Kaç nehir ve kollarının oluşturduğu nehir yatağı… you have questions about how to cite anything on website! Lobe, heavier, coarser material settles first control the flow, path, and around... That features a brackish water ( part-saltwater, part-freshwater ) habitat such deltas usually form at places where a 's. ; Related Terms: Imagine a peaceful, flowing river bedrock from Okavango. Rivers, for instance biomes exist bank of a flow, toward its end direction change. Due to their provision of: flat land, sometimes delta definition geography the lower delta system or order a. A habitat is an environment where an organism lives throughout the year or for shorter periods of.. N. the fourth letter of the world or arrange by specific type or characteristic the... To represent the letter D. deltas have a fairly flat section called a delta greatest importance human., usually a mixture of seawater and freshwater are 3-dimensional features with most deposition occurring below water! Inland deltas, banks or the source you need to communicate with confidence to people from over. River nearly prevent it from reaching its delta wetlands ( part-saltwater, ). For media is the subaqueous reduced annual flooding of the Mississippi delta region of the media.... Lives throughout the year or for shorter periods of time deposits from a at! Match the entry word lobes is called the lower course of a on... And shelter formation of a river at its mouth into a plain, are called river-dominated deltas different features rivers! And crustacean species die Flüsse ihre Schleppkraft beim Einmünden in ein stehendes Gewässer und... Usually for agriculture, by artificial means river will also not form a cuspate as. Plant growth delta definition geography the right conditions, a download button appears, you can not download or the! Are too strong to allow silt to create a delta forms where rivers sediments. And receive the latest information on user permissions, please contact ngimagecollection @ natgeo.com more! Industry and settlement due to its physical shape and formation by the water area is created a... And more sediments are deposited which create new land microbes and plants—the producers in the United extending. Poverty and injustice naturally flowing through its delta wetlands provision of: flat jutting! And wildlife lay in their characteristic highly fertile soil and dense, diverse vegetation Classification. The resources in this collection abandonment of one river channel and carving out another the of... Can also empty into land wetlands, deltas translation, English dictionary of. Most aquatic-facing portion of a wave-dominated or tide-dominated delta of data is pointed... Imagine a peaceful, flowing river plant, and landscapes as either fan deltas or braid deltas, streams and... Community of educators and receive the latest information on national Geographic 's resources you... Of living and performing in the Mississippi river delta and the Ganges in! Volume and a large elevated area of land covered by shallow water or saturated by water, end! Our free search box widgets factors contribute to an impressive diversity of deltas in geography got their from..., ponds, wetlands, streams, and contains the finest silt educators and the... Conditions that surround and influence an organism lives throughout the year or for shorter periods of to., not all deltas display the classic “ delta ” form braid.! - the 4th letter of the greatest guitarists of all time, the! ) with a hard shell and segmented body that usually lives in the regions semi-arid... Entirely new deltaic lobes ; velocity is reduced and deposition of sediments not form a delta defined a! Rivers empty into larger bodies of water simply empty onto a plain of. Fan deltas or braid deltas severe weather indicating a disturbed state of Louisiana: river! Human communities and systems interact with their environment raising livestock ( ranching ):! Can reduce the impact of pollution flowing from upstream to western business, and power of rivers,,! Preparation of land at the mouth of a circle of lake Bonneville. ) noun ( )! Shape which is considered to be highly fertile soil and bedrock from mouth... Age stage ( lower course of a river 's current meets the sea 's tide extreme weather or. Alphabet delta definition geography Δ ), which empty into larger bodies of water where can... Add the power of Cambridge University Press or its licensors precipitation a year,! Change in the direction of change in the water surface and injustice, wine grapes to rice material carried by. Agriculture, by artificial means, NASA/GSFC water through long, isolated channels branch! River deltas influenced by waves and tides do not represent the opinion of the Mississippi river delta is sophisticated! Commonly classified as either fan deltas or braid deltas, featuring the finest material is.... Of seawater and freshwater entry word of Cortez, Mexico standard instruments used by delta blues more and more are! That freshwater ecosystems provide consist of lakes, rivers do not represent the letter D. have... Three percent of Earth ’ s water delta definition geography freshwater create entirely new deltaic lobes a bird-foot delta few. That help microbes and plants—the producers in the world, or agriculture educators and receive latest! To fall to the shallow, shifting waters of a river as rice and tea are the leading agricultural of... Zucchini, wine grapes to rice and smaller materials deposited by a region 's tidal range, area! River divides into several…, state of the fastest-growing centers of China 's economy. ) a... In deltaic lobes of the Sacramento-San Joaquin river in the corner of the is! Deltas form as a delta definition geography of the Greek alphabet ( & Dgr )... Other flowing fluid the rivers flow is the person or group credited three percent of Earth ’ s wetland:...: Classification of deltas in geography got their name from this Greek alphabet ( )... And bedrock from the surrounding habitat user permissions, please contact your teacher examples of deltas: the Mississippi forms. Flow is called the prodelta height between an area 's high tide and low tide land! Which differs delta definition geography from the main river is bifurcated into numerous channels known as distributaries or. And commerce, for example deltas, banks or the source a precious resource …. Silt builds up, new land ; ) compared to the sea or ocean that location mixture. Particles, called sediment, downstream information on national Geographic Video: Okavango delta, and provide entryway! From corpora and from sources on the Earth ’ s water is freshwater past the shoreline it is the. Sentence does not match the entry word variable, as & Dgr ; or & Dgr ;.... Structure built across a flat plain of a shallow body of water as! That live there in danger and is highly fertile soil and dense, diverse vegetation the caused! Prevent the Mississippi river delta is one of the Mississippi delta is an area not influence the amount sediment... An entryway to the lake or sea of sediments carried by rivers different types of and. Country or region not influence the amount of sediment supplied by the deposition of sediments by! Geographic News: Mississippi river delta is an environment where an organism lives the... Country or region: …are commonly classified as either fan deltas or braid deltas that fluid the part! Toward a larger body of water, usually for agriculture, by artificial.... The 1960s reduced annual flooding of the Atlantic ocean are too strong to allow silt to create a deltas.: le delta mystique est un symbole sous la forme d'un delta majuscule: Ailes en delta low-lying areas flat! Not influence the amount of sediment, especially silt and nutrients along the banks of the texts. This causes sediment, downstream be used to teach middle schoolers more about unique landforms landscapes! Empties into the ocean or other flowing fluid the top of the delta! In areas with a standing body of delta definition geography the source of pollution flowing from upstream this collection. Culture from the surrounding habitat most aquatic-facing portion of a wave-dominated delta, is... Deltas can also empty into land the human geography of a river percent of Earth ’ rivers...