Stream

A stream is a body of water[1] with surface water flowing within the bed and banks of a channel. The stream encompasses surface and groundwater fluxes that respond to geological, geomorphological, hydrological and biotic controls.[2]

Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long large streams are usually called rivers.

Streams are important as conduits in the water cycle, instruments in groundwater recharge, and corridors for fish and wildlife migration. The biological habitat in the immediate vicinity of a stream is called a riparian zone. Given the status of the ongoing Holocene extinction, streams play an important corridor role in connecting fragmented habitats and thus in conserving biodiversity. The study of streams and waterways in general is known as surface hydrology and is a core element of environmental geography.[3]

Aubach (Wiehl) nahe des Weiherdamms in Wildbergerhütte
Aubach (Wiehl) in North Rhine-Westphalia, Germany
Potok pod jezerom 1
Rocky stream in Italy

Types

SpearfishCreek
A rocky creek in Spearfish Canyon, South Dakota, US
Creek babbling through Benvoulin, Canada wetlands
Brook
Brook near the Bay of Fundy, Canada
Parramattastream
A small stream in Lake Parramatta, Sydney
Stevens Creek Tributary A in Macon County, IL
A low level stream in Macon County, Illinois, US
Brook
A stream smaller than a creek, especially one that is fed by a spring or seep. It is usually small and easily forded. A brook is characterised by its shallowness.
Creek (/kriːk/) or crick (/krɪk/)[4][5]
River
A large natural stream, which may be a waterway.[13]
Runnel
The linear channel between the parallel ridges or bars on a shoreline beach or river floodplain, or between a bar and the shore. Also called a swale.
Tributary
A contributory stream, or a stream which does not reach a static body of water such as a lake or ocean,[14] but joins another river (a parent river). Sometimes also called a branch or fork.[15]

Other names

There are a number of regional names for a stream.

United Kingdom

North America

Other terminology

Bar
A shoal that develops in a stream as sediment is deposited as the current slows or is impeded by wave action at the confluence.
Bifurcation
A fork into two or more streams.
Channel
A depression created by constant erosion that carries the stream's flow.
Confluence
The point at which the two streams merge. If the two tributaries are of approximately equal size, the confluence may be called a fork.
Drainage basin
(also known as a watershed in the United States) The area of land where water flows into a stream. A large drainage basin such as the Amazon River contains many smaller drainage basins.[27]
Floodplain
Lands adjacent to the stream that are subject to flooding when a stream overflows its banks.[27]
Gaging station
A site along the route of a stream or river, used for reference marking or water monitoring.[27]
Headwaters
The part of a stream or river proximate to its source. The word is most commonly used in the plural where there is no single point source.[27]
Knickpoint
The point on a stream's profile where a sudden change in stream gradient occurs.
Mouth
The point at which the stream discharges, possibly via an estuary or delta, into a static body of water such as a lake or ocean.
Pool
A segment where the water is deeper and slower moving.
Rapids
A turbulent, fast-flowing stretch of a stream or river.
Riffle
A segment where the flow is shallower and more turbulent.
River
A large natural stream, which may be a waterway.[27]
Run
A somewhat smoothly flowing segment of the stream.
Source
The spring from which the stream originates, or other point of origin of a stream.
Spring
The point at which a stream emerges from an underground course through unconsolidated sediments or through caves. A stream can, especially with caves, flow aboveground for part of its course, and underground for part of its course.[27]
Stream bed
The bottom of a stream.
Stream corridor
Stream, its floodplains, and the transitional upland fringe[28]
Streamflow
The water moving through a stream channel.[27]
Thalweg
The river's longitudinal section, or the line joining the deepest point in the channel at each stage from source to mouth.
Waterfall or cascade
The fall of water where the stream goes over a sudden drop called a knickpoint; some knickpoints are formed by erosion when water flows over an especially resistant stratum, followed by one less so. The stream expends kinetic energy in "trying" to eliminate the knickpoint.
Wetted perimeter
The line on which the stream's surface meets the channel walls.

Sources

Homesteadcreekflowers
Small tributary stream, Diamond Ridge, Alaska, US
Creek in perisher
Creek in Perisher Ski Resort, Australia

Streams typically derive most of their water from precipitation in the form of rain and snow. Most of this water re-enters the atmosphere by evaporation from soil and water bodies, or by the evapotranspiration of plants. Some of the water proceeds to sink into the earth by infiltration and becomes groundwater, much of which eventually enters streams. Some precipitated water is temporarily locked up in snow fields and glaciers, to be released later by evaporation or melting. The rest of the water flows off the land as runoff, the proportion of which varies according to many factors, such as wind, humidity, vegetation, rock types, and relief. This runoff starts as a thin film called sheet wash, combined with a network of tiny rills, together constituting sheet runoff; when this water is concentrated in a channel, a stream has its birth. Some creeks may start from ponds or lakes.

Audubon Society long exposure
Stream in Southbury, Connecticut, US

Characteristics

Ranking

To qualify as a stream, a body of water must be either recurring or perennial. Recurring (intermittent) streams have water in the channel for at least part of the year. A stream of the first order is a stream which does not have any other recurring or perennial stream feeding into it. When two first-order streams come together, they form a second-order stream. When two second-order streams come together, they form a third-order stream. Streams of lower order joining a higher order stream do not change the order of the higher stream. Thus, if a first-order stream joins a second-order stream, it remains a second-order stream. It is not until a second-order stream combines with another second-order stream that it becomes a third-order stream.

Gradient

The gradient of a stream is a critical factor in determining its character and is entirely determined by its base level of erosion. The base level of erosion is the point at which the stream either enters the ocean, a lake or pond, or enters a stretch in which it has a much lower gradient, and may be specifically applied to any particular stretch of a stream.

In geological terms, the stream will erode down through its bed to achieve the base level of erosion throughout its course. If this base level is low, then the stream will rapidly cut through underlying strata and have a steep gradient, and if the base level is relatively high, then the stream will form a flood plain and meander.

Meander

Meanders are looping changes of direction of a stream caused by the erosion and deposition of bank materials. These are typically serpentine in form. Typically, over time the meanders gradually migrate downstream.

If some resistant material slows or stops the downstream movement of a meander, a stream may erode through the neck between two legs of a meander to become temporarily straighter, leaving behind an arc-shaped body of water termed an oxbow lake or bayou. A flood may also cause a meander to be cut through in this way.

Profile

Typically, streams are said to have a particular profile, beginning with steep gradients, no flood plain, and little shifting of channels, eventually evolving into streams with low gradients, wide flood plains, and extensive meanders. The initial stage is sometimes termed a "young" or "immature" stream, and the later state a "mature" or "old" stream. However, a stream may meander for some distance before falling into a "young" stream condition.

Stream load

Streams can carry sediment, or alluvium. The amount of load it can carry (capacity) as well as the largest object it can carry (competence) are both dependent on the velocity of the stream.

Intermittent and ephemeral streams

Low creek
Australian creek, low in the dry season, carrying little water. The energetic flow of the stream had, in flood, moved finer sediment further downstream. There is a pool to lower right and a riffle to upper left of the photograph.

A perennial stream is one which flows continuously all year.[29]:57 Some perennial streams may only have continuous flow in segments of its stream bed year round during years of normal rainfall.[30][31]

Blue-line streams are perennial streams and are marked on topographic maps with a solid blue line.

Ephemeral stream

Generally, streams that flow only during and immediately after precipitation are termed ephemeral. There is no clear demarcation between surface runoff and an ephemeral stream,[29]:58 and some ephemeral streams can be classed as intermittent—flow all but disappearing in the normal course of seasons but ample flow (backups) restoring stream presence—such circumstances are documented when stream beds have opened up a path into mines or other underground chambers.[32]

Intermittent stream

or seasonal stream

In the United States, an intermittent or seasonal stream is one that only flows for part of the year and is marked on topographic maps with a line of blue dashes and dots.[29]:57–58 A wash or desert wash is normally a dry streambed in the deserts of the American Southwest which flows only after significant rainfall. Washes can fill up quickly during rains, and there may be a sudden torrent of water after a thunderstorm begins upstream, such as during monsoonal conditions. These flash floods often catch travelers by surprise. An intermittent stream can also be called an arroyo in Latin America, a winterbourne in Britain, or a wadi in the Arabic-speaking world.

In Italy, an intermittent stream is termed a torrent (Italian torrente). In full flood the stream may or may not be "torrential" in the dramatic sense of the word, but there will be one or more seasons in which the flow is reduced to a trickle or less. Typically torrents have Apennine rather than Alpine sources, and in the summer they are fed by little precipitation and no melting snow. In this case the maximum discharge will be during the spring and autumn. However, there are also glacial torrents with a different seasonal regime.

In Australia, an intermittent stream is usually called a creek and marked on topographic maps with a solid blue line.

Drainage basins

The extent of land basin drained by a stream is termed its drainage basin (also known in North America as the watershed and, in British English, as a catchment).[33] A basin may also be composed of smaller basins. For instance, the Continental Divide in North America divides the mainly easterly-draining Atlantic Ocean and Arctic Ocean basins from the largely westerly-flowing Pacific Ocean basin. The Atlantic Ocean basin, however, may be further subdivided into the Atlantic Ocean and Gulf of Mexico drainages. (This delineation is termed the Eastern Continental Divide.) Similarly, the Gulf of Mexico basin may be divided into the Mississippi River basin and several smaller basins, such as the Tombigbee River basin. Continuing in this vein, a component of the Mississippi River basin is the Ohio River basin, which in turn includes the Kentucky River basin, and so forth.

Crossings

Stream crossings are where streams are crossed by roads, pipelines, railways, or any other thing which might restrict the flow of the steam in ordinary or flood conditions. Any structure over or in a stream which results in limitations on the movement of fish or other ecological elements may be an issue.

See also

References

  1. ^ Langbein, W.B.; Iseri, Kathleen T. (1995). "Hydrologic Definitions: Stream". Manual of Hydrology: Part 1. General Surface-Water Techniques (Water Supply Paper 1541-A). Reston, VA: USGS. Archived from the original on 2012-05-09.
  2. ^ Alexander, L. C., Autrey, B., DeMeester, J., Fritz, K. M., Golden, H. E., Goodrich, D. C., ... & McManus, M. G. (2015). Connectivity of streams and wetlands to downstream waters: review and synthesis of the scientific evidence (Vol. 475). EPA/600/R-14.
  3. ^ "What is hydrology and what do hydrologists do?" Archived 2014-02-22 at the Wayback Machine U.S. Geological Survey (USGS). Atlanta, GA. 2009-05-13.
  4. ^ "creek". dictionary.com. Dictionary.com, LLC. Retrieved 16 May 2019. kreek, krik
  5. ^ "crick". English Oxford Living Dictionaries. Oxford University Press. Retrieved 18 May 2019. Northern, North Midland, and Western U.S.
  6. ^ "creek". oxforddictionaries.com. Oxford University Press. Retrieved 18 May 2019. British...especially an inlet...(whereas) NZ, North American, Australian...stream or minor tributary.
  7. ^ "(US) creek". English Oxford Living Dictionaries. Oxford University Press. Retrieved 18 May 2019. North American, Australian, NZ...A stream, brook, or minor tributary of a river.
  8. ^ "creek". Dictionary.com. Dictionary.com, LLC. Retrieved 18 May 2019. U.S., Canada , and Australia…a stream smaller than a river.
  9. ^ "creek". Collins. Collins. Retrieved 18 May 2019. US, Canadian, Australian and New Zealand a small stream or tributary
  10. ^ "creek". Macmillan Dictionary. Springer Nature Limited. Retrieved 18 May 2019. a narrow stream
  11. ^ [6][7][8][9][10]
  12. ^ Spruce Creek Association. Kittery, ME. "About the Spruce Creek Watershed." Archived 2008-07-03 at the Wayback Machine Accessed 2010-10-02.
  13. ^ Wetzel, Robert G. (2001). Limnology: Lake and river ecosystems (3rd ed.). San Diego: Academic Press. ISBN 978-0127447605. OCLC 46393244.
  14. ^ Krebs, Robert E. (2003). The Basics of Earth Science. Greenwood Publishing Group. ISBN 978-0-313-31930-3.
  15. ^ Bisson, Peter and Wondzell, Steven. “Olympic Experimental State Forest Synthesis of Riparian Research and Monitoring”, United States Forest Service, p. 15 (December 1, 2009).
  16. ^ "OED Online - Beck". Oxford University Press. June 2017. Retrieved 6 July 2017.
  17. ^ "OED Online - Bourne". Oxford University Press. June 2017. Retrieved 6 July 2017.
  18. ^ "OED Online - Brook". Oxford University Press. June 2017. Retrieved 6 July 2017.
  19. ^ "OED Online - Burn". Oxford University Press. June 2017. Retrieved 6 July 2017.
  20. ^ "OED Online - Gill". Oxford University Press. June 2017. Retrieved 6 July 2017.
  21. ^ "OED Online - Nant". Oxford University Press. June 2017. Retrieved 6 July 2017.
  22. ^ "OED Online - Rivulet". Oxford University Press. June 2017. Retrieved 6 July 2017.
  23. ^ "OED Online - Sike". Oxford University Press. June 2017. Retrieved 6 July 2017.
  24. ^ "OED Online -Branch". Oxford University Press. June 2017. Retrieved 6 July 2017.
  25. ^ a b "Derek Watkin's USGS Analysis". Retrieved 26 November 2018.
  26. ^ Steigerwalt, Nancy M.; Cichra, Charles E.; Baker, Shirley M. (2008). "Composition and Distribution of Aquatic Invertebrate Communities on Snags in a North Central Florida, USA, Spring-Run Stream". Florida Scientist. 71 (3): 273–286. JSTOR 24321406.
  27. ^ a b c d e f g "USGS Water Science Glossary of Terms". United States Geological Survey. 26 November 2018.
  28. ^ "Stream Corridor Structure" Archived 2015-04-02 at the Wayback Machine Adapted from Stream Corridor Restoration: Principles, Processes, and Practices
  29. ^ a b c Meinzer, Oscar E. (1923). Outline of ground-water hydrology, with definitions. Washington, DC: USGS. Archived from the original on 2017-07-09. Water Supply Paper 494.
  30. ^ Meinzer, Oscar E. (1923). Outline of ground-water hydrology, with definitions. Washington, DC: US Geological Survey (USGS). p. 57. Archived from the original on 2017-07-09. Water Supply Paper 494.
  31. ^ "OSM - COALEX State Inquiry Report 97". Archived from the original on 2012-04-15. Retrieved 2011-12-11.
  32. ^ Black Creek (Susquehanna River)#Hydrology_and_climate, `Black Creek is an ephemeral stream. It used to drain an area between Turtle Creek and the Susquehanna River, but now loses its flow to underground mines via broken bedrock. Its channel is also disrupted by strip mines and rock piles.', 14 Nov 2016.
  33. ^ Langbein, W.B.; Iseri, Kathleen T. (1995). "Hydrologic Definitions: Watershed". Manual of Hydrology: Part 1. General Surface-Water Techniques (Water Supply Paper 1541-A). Reston, VA: USGS. Archived from the original on 2012-05-09.

External links

Body of water

A body of water or waterbody (often spelled water body) is any significant accumulation of water, generally on a planet's surface. The term most often refers to oceans, seas, and lakes, but it includes smaller pools of water such as ponds, wetlands, or more rarely, puddles. A body of water does not have to be still or contained; rivers, streams, canals, and other geographical features where water moves from one place to another are also considered bodies of water.Most are naturally occurring geographical features, but some are artificial. There are types that can be either. For example, most reservoirs are created by engineering dams, but some natural lakes are used as reservoirs. Similarly, most harbors are naturally occurring bays, but some harbors have been created through construction.

Bodies of water that are navigable are known as waterways. Some bodies of water collect and move water, such as rivers and streams, and others primarily hold water, such as lakes and oceans.

The term body of water can also refer to a reservoir of water held by a plant, technically known as a phytotelma.

Bodies of water are affected by gravity which is what creates the tidal effects on Earth.

Direct-to-video

Direct-to-video or straight-to-video refers to the release of a film to the public immediately on home video formats rather than a theatrical release or television broadcast.Because inferior sequels or prequels of larger-budget films may be released direct-to-video, review references to direct-to-video releases are often pejorative. Direct-to-video release has also become profitable for independent filmmakers and smaller companies. It is not unusual for a direct-to-video genre film (with a high-profile star) to generate well in excess of $50 million revenue worldwide.

Discharge (hydrology)

In hydrology, discharge is the volumetric flow rate of water that is transported through a given cross-sectional area. It includes any suspended solids (e.g. sediment), dissolved chemicals (e.g. CaCO3(aq)), or biologic material (e.g. diatoms) in addition to the water itself.

Synonyms vary by discipline. For example, a fluvial hydrologist studying natural river systems may define discharge as streamflow, whereas an engineer operating a reservoir system might define discharge as outflow, which is contrasted with inflow.

Google Stadia

Stadia is an upcoming cloud gaming service operated by Google. It is said to be capable of streaming video games up to 4K resolution at 60 frames per second with support for high-dynamic-range, to players via the company's numerous data centers across the globe, provided they are using a sufficiently high-speed Internet connection. It will be accessible through the desktop Google Chrome web browser, on smartphones, smart televisions and tablets, or through Chromecast.The service is integrated with YouTube, and its "state share" feature allows viewers of a Stadia stream to launch a game on the service on the same save state as the streamer. This has been used as a selling point for the service. It is compatible with HID class USB controllers, though a proprietary controller manufactured by Google with a direct Wi-Fi link to data centers will be available alongside the service. Stadia is not similar to Netflix, requiring users to purchase games to stream via Stadia rather than pay for access to a library of games. While the base service will be free, a Pro tier monthly subscription allows users to stream at higher rates for larger resolutions, and the offer to add free games to their library.

Known in development as Project Stream, the service was debuted through a closed beta running Assassin's Creed Odyssey in October 2018, with a public release planned in November 2019 in selected countries. It competes with Sony's PlayStation Now service, Nvidia's GeForce Now, and Microsoft's Project xCloud.

Gulf Stream

The Gulf Stream, together with its northern extension the North Atlantic Drift, is a warm and swift Atlantic ocean current that originates in the Gulf of Mexico and stretches to the tip of Florida, and follows the eastern coastlines of the United States and Newfoundland before crossing the Atlantic Ocean. The process of western intensification causes the Gulf Stream to be a northward accelerating current off the east coast of North America. At about 40°0′N 30°0′W, it splits in two, with the northern stream, the North Atlantic Drift, crossing to Northern Europe and the southern stream, the Canary Current, recirculating off West Africa.

The Gulf Stream influences the climate of the east coast of North America from Florida to Newfoundland, and the west coast of Europe. Although there has been recent debate, there is consensus that the climate of Western Europe and Northern Europe is warmer than it would otherwise be due to the North Atlantic drift which is the northeastern section of the Gulf Stream. It is part of the North Atlantic Gyre. Its presence has led to the development of strong cyclones of all types, both within the atmosphere and within the ocean. The Gulf Stream is also a significant potential source of renewable power generation.The Gulf Stream is typically 100 kilometres (62 mi) wide and 800 metres (2,600 ft) to 1,200 metres (3,900 ft) deep. The current velocity is fastest near the surface, with the maximum speed typically about 2.5 metres per second (9.0 km/h; 5.6 mph).

ICloud

iCloud is a cloud storage and cloud computing service from Apple Inc. launched on October 12, 2011. As of 2018, the service had an estimated 850 million users, up from 782 million users in 2016.iCloud enables users to store data such as documents, photos, and music on remote servers for download to iOS, macOS or Windows devices, to share and send data to other users, and to manage their Apple devices if lost or stolen.

iCloud also provides the means to wirelessly back up iOS devices directly to iCloud, instead of being reliant on manual backups to a host Mac or Windows computer using iTunes. Service users are also able to share photos, music, and games instantly by linking accounts via AirDrop wireless.

iCloud replaced Apple's MobileMe service, acting as a data syncing center for email, contacts, calendars, bookmarks, notes, reminders (to-do lists), iWork documents, photos, and other data.

Apple has eleven company owned and operated data centers supporting iCloud services. The company has six data centers in the United States, two in Denmark, and three in Asia. One of Apple's original iCloud data centers is located in Maiden, North Carolina, US.Beginning in 2011, iCloud is based on Amazon Web Services and Microsoft Azure (Apple iOS Security white paper published in 2014, Apple acknowledged that encrypted iOS files are stored in Amazon S3 and Microsoft Azure). In 2016, Apple signed a deal with Google to use Google Cloud Platform for some iCloud services.In October 2016, Bloomberg reported that Apple was working on project Pie which aims to improve the speed and experience of Apple's online services by being operated more directly by Apple. Also it was reported that Apple was going to relocate all of its services employees to the Apple Campus (1 Infinite Loop, Cupertino, California), as many other employees would be moving to the Apple Park.

Jet stream

Jet streams are fast flowing, narrow, meandering air currents in the atmospheres of some planets, including Earth. On Earth, the main jet streams are located near the altitude of the tropopause and are westerly winds (flowing west to east). Their paths typically have a meandering shape. Jet streams may start, stop, split into two or more parts, combine into one stream, or flow in various directions including opposite to the direction of the remainder of the jet.

The strongest jet streams are the polar jets, at 9–12 km (30,000–39,000 ft) above sea level, and the higher altitude and somewhat weaker subtropical jets at 10–16 km (33,000–52,000 ft). The Northern Hemisphere and the Southern Hemisphere each have a polar jet and a subtropical jet. The northern hemisphere polar jet flows over the middle to northern latitudes of North America, Europe, and Asia and their intervening oceans, while the southern hemisphere polar jet mostly circles Antarctica all year round.

Jet streams are the product of two factors: the atmospheric heating by solar radiation that produces the large-scale Polar, Ferrel, and Hadley circulation cells, and the action of the Coriolis force acting on those moving masses. The Coriolis force is caused by the planet's rotation on its axis. On other planets, internal heat rather than solar heating drives their jet streams. The Polar jet stream forms near the interface of the Polar and Ferrel circulation cells; the subtropical jet forms near the boundary of the Ferrel and Hadley circulation cells.Other jet streams also exist. During the Northern Hemisphere summer, easterly jets can form in tropical regions, typically where dry air encounters more humid air at high altitudes. Low-level jets also are typical of various regions such as the central United States. There are also jet streams in the thermosphere.

Meteorologists use the location of some of the jet streams as an aid in weather forecasting. The main commercial relevance of the jet streams is in air travel, as flight time can be dramatically affected by either flying with the flow or against, which results in significant fuel and time cost savings for airlines. Often, the airlines work to fly 'with' the jet stream for this reason. Dynamic North Atlantic Tracks are one example of how airlines and air traffic control work together to accommodate the jet stream and winds aloft that results in the maximum benefit for airlines and other users. Clear-air turbulence, a potential hazard to aircraft passenger safety, is often found in a jet stream's vicinity, but it does not create a substantial alteration on flight times.

Mindstream

Mindstream (citta-santāna) in Buddhist philosophy is the moment-to-moment continuum (Sanskrit: saṃtāna) of sense impressions and mental phenomena, which is also described as continuing from one life to another.

Ninja (streamer)

Richard Tyler Blevins (born June 5, 1991), better known by his online alias Ninja (formerly NinjasHyper), is an American streamer, YouTuber, professional gamer, and Internet personality. As of July 2019, he is the most followed streamer on Twitch.tv with over fourteen million followers and an average of over 50,000 viewers per week. In August 2019, Blevins announced he was moving to Twitch competitor Mixer fulltime.

Pyroclastic flow

A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that moves away from a volcano about 100 km/h (62 mph) on average but is capable of reaching speeds up to 700 km/h (430 mph). The gases can reach temperatures of about 1,000 °C (1,830 °F).

Pyroclastic flows are a common and devastating result of certain explosive eruptions; they normally touch the ground and hurtle downhill, or spread laterally under gravity. Their speed depends upon the density of the current, the volcanic output rate, and the gradient of the slope.

River mouth

A river mouth is the part of a river where the river debouches into another river, a lake, a reservoir, a sea, or an ocean.

River source

The source, or headwaters, of a river or stream is the furthest place in that river or stream from its estuary or confluence with another river, as measured along the course of the river.

Sotāpanna

In Buddhism, a sotāpanna (Pali), śrotāpanna (Sanskrit; Chinese: 入流; pinyin: rùliú, Chinese: 须陀洹; pinyin: xū tuó huán, Burmese: သောတာပန်, Tibetan: རྒྱུན་ཞུགས་, Wylie: rgyun zhugs), "stream-winner", or "stream-entrant" is a person who has seen the Dharma and consequently, has dropped the first three fetters (saŋyojana) that bind a being to rebirth, namely self-view (sakkāya-ditthi), clinging to rites and rituals (sīlabbata-parāmāsa), and skeptical indecision (Vicikitsa).

The word sotāpanna literally means "one who entered (āpanna) the stream (sota)", after a metaphor which calls the noble eightfold path a stream which leads to nibbāna. Entering the stream (sotāpatti) is the first of the four stages of enlightenment.

Steve Buscemi

Steven Vincent Buscemi ( boo-SEM-i, Italian: [buʃˈʃɛːmi]; born December 13, 1957) is an American actor, filmmaker and former firefighter. He has starred in films such as Parting Glances, New York Stories, Mystery Train, Reservoir Dogs, Desperado, Con Air, Armageddon, The Grey Zone, Ghost World, Big Fish, and The Death of Stalin. He is also known for his supporting roles in the Coen brothers films Miller's Crossing, Barton Fink, The Hudsucker Proxy, Fargo and The Big Lebowski. He provides the voice of Randall Boggs in the Monsters, Inc. franchise and Wayne the Werewolf in the Hotel Transylvania film series.

From 2010 to 2014, Buscemi portrayed Enoch "Nucky" Thompson in the critically acclaimed series Boardwalk Empire, which earned him two Screen Actors Guild Awards, a Golden Globe and two nominations for an Emmy Award. He made his directorial debut with Trees Lounge (1996), in which he also starred. Other films he has directed include Animal Factory, Lonesome Jim and Interview. He has directed episodes of Homicide: Life on the Street, The Sopranos, Oz, 30 Rock and Nurse Jackie.

He is also known for portraying Pete Wittel in the tragicomedy web series Horace and Pete.

Stream cipher

A stream cipher is a symmetric key cipher where plaintext digits are combined with a pseudorandom cipher digit stream (keystream). In a stream cipher, each plaintext digit is encrypted one at a time with the corresponding digit of the keystream, to give a digit of the ciphertext stream. Since encryption of each digit is dependent on the current state of the cipher, it is also known as state cipher. In practice, a digit is typically a bit and the combining operation an exclusive-or (XOR).

The pseudorandom keystream is typically generated serially from a random seed value using digital shift registers. The seed value serves as the cryptographic key for decrypting the ciphertext stream. Stream ciphers represent a different approach to symmetric encryption from block ciphers. Block ciphers operate on large blocks of digits with a fixed, unvarying transformation. This distinction is not always clear-cut: in some modes of operation, a block cipher primitive is used in such a way that it acts effectively as a stream cipher. Stream ciphers typically execute at a higher speed than block ciphers and have lower hardware complexity. However, stream ciphers can be susceptible to serious security problems if used incorrectly (see stream cipher attacks); in particular, the same starting state (seed) must never be used twice.

Stream of consciousness

In literary criticism, stream of consciousness is a narrative mode or method that attempts "to depict the multitudinous thoughts and feelings which pass through the mind" of a narrator. The term was coined by Alexander Bain in 1855 in the first edition of The Senses and the Intellect, when he wrote, "The concurrence of Sensations in one common stream of consciousness (on the same cerebral highway) enables those of different senses to be associated as readily as the sensations of the same sense" (p. 359). But it is commonly credited to William James who used it in 1890 in his The Principles of Psychology. In 1918, the novelist May Sinclair (1863–1946) first applied the term stream of consciousness, in a literary context, when discussing Dorothy Richardson's (1873–1957) novels. Pointed Roofs (1915), the first work in Richardson's series of 13 semi-autobiographical novels titled Pilgrimage, is the first complete stream-of-consciousness novel published in English. However, in 1934, Richardson comments that "Proust, James Joyce, Virginia Woolf & D.R. ... were all using 'the new method', though very differently, simultaneously". There were, however, many earlier precursors and the technique is still used by contemporary writers.

Streaming media

Streaming media is multimedia that is constantly received by and presented to an end-user while being delivered by a provider. The verb "to stream" refers to the process of delivering or obtaining media in this manner; the term refers to the delivery method of the medium, rather than the medium itself, and is an alternative to file downloading, a process in which the end-user obtains the entire file for the content before watching or listening to it.

A client end-user can use their media player to start playing digital video or digital audio content before the entire file has been transmitted. Distinguishing delivery method from the media distributed applies specifically to telecommunications networks, as most of the delivery systems are either inherently streaming (e.g. radio, television, streaming apps) or inherently non-streaming (e.g. books, video cassettes, audio CDs). For example, in the 1930s, elevator music was among the earliest popular music available as streaming media; nowadays Internet television is a common form of streamed media. The term "streaming media" can apply to media other than video and audio, such as live closed captioning, ticker tape, and real-time text, which are all considered "streaming text".

Live streaming is the delivery of Internet content in real-time much as live television broadcasts content over the airwaves via a television signal. Live internet streaming requires a form of source media (e.g. a video camera, an audio interface, screen capture software), an encoder to digitize the content, a media publisher, and a content delivery network to distribute and deliver the content. Live streaming does not need to be recorded at the origination point, although it frequently is.

There are challenges with streaming content on the Internet. If the user does not have enough bandwidth in their Internet connection, they may experience stops, lags, or slow buffering of the content. Some users may not be able to stream certain content due to not having compatible computer or software systems.

Some popular streaming services include the video sharing website YouTube; Netflix, Prime Video, Hulu and others which stream films and television shows; Spotify and Apple Music which stream music; and the video game live streaming sites Twitch and Mixer.

Tributary

A tributary or affluent is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drainage basin of its surface water and groundwater, leading the water out into an ocean.

A confluence, where two or more bodies of water meet together, usually refers to the joining of tributaries.

The opposite to a tributary is a distributary, a river or stream that branches off from and flows away from the main stream. Distributaries are most often found in river deltas.

Water pollution

Water pollution is the contamination of water bodies, usually as a result of human activities. Water bodies include for example lakes, rivers, oceans, aquifers and groundwater. Water pollution results when contaminants are introduced into the natural environment. For example, releasing inadequately treated wastewater into natural water bodies can lead to degradation of aquatic ecosystems. In turn, this can lead to public health problems for people living downstream. They may use the same polluted river water for drinking or bathing or irrigation. Water pollution is the leading worldwide cause of death and disease, e.g. due to water-borne diseases.Water pollution can be grouped into surface water pollution. Marine pollution and nutrient pollution are subsets of water pollution. Sources of water pollution are either point sources and non-point sources. Point sources have one identifiable cause of the pollution, such as a storm drain, wastewater treatment plant or stream. Non-point sources are more diffuse, such as agricultural runoff. Pollution is the result of the cumulative effect over time. All plants and organisms living in or being exposed to polluted water bodies can be impacted. The effects can damage individual species and impact the natural biological communities they are part of.

The causes of water pollution include a wide range of chemicals and pathogens as well as physical parameters. Contaminants may include organic and inorganic substances. Elevated temperatures can also lead to polluted water. A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers. Elevated water temperatures decrease oxygen levels, which can kill fish and alter food chain composition, reduce species biodiversity, and foster invasion by new thermophilic species.Water pollution is measured by analysing water samples. Physical, chemical and biological tests can be done. Control of water pollution requires appropriate infrastructure and management plans. The infrastructure may include wastewater treatment plants. Sewage treatment plants and industrial wastewater treatment plants are usually required to protect water bodies from untreated wastewater. Agricultural wastewater treatment for farms, and erosion control from construction sites can also help prevent water pollution. Nature-based solutions are another approach to prevent water pollution. Effective control of urban runoff includes reducing speed and quantity of flow. In the United States, best management practices for water pollution include approaches to reduce the quantity of water and improve water quality.

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