Stream bed

A stream bed or streambed is the channel bottom of a stream or river, the physical confine of the normal water flow. The lateral confines or channel margins are known as the stream banks or river banks, during all but flood stage. Under certain conditions a river can branch from one stream bed to multiple stream beds.[1] A flood occurs when a stream overflows its banks and flows onto its flood plain. As a general rule, the bed is the part of the channel up to the normal water line, and the banks are that part above the normal water line. However, because water flow varies, this differentiation is subject to local interpretation. Usually, the bed is kept clear of terrestrial vegetation, whereas the banks are subjected to water flow only during unusual or perhaps infrequent high water stages and therefore might support vegetation some or much of the time.

Old Mississippi riverbed near St. Mary's
The old bed of the Mississippi River near Kaskaskia, Illinois, left behind after the river shifted
Digging for drinking water in a dry riverbed (6220146368)
A woman digs in a dry stream bed in Kenya to find water during a drought.

The nature of any stream bed is always a function of the flow dynamics and the local geologic materials, influenced by that flow. With small streams in mesophytic regions, the nature of the stream bed is strongly responsive to conditions of precipitation runoff. Where natural conditions of either grassland or forest ameliorate peak flows, stream beds are stable, possibly rich, with organic matter and exhibit minimal scour. These streams support a rich biota. Where conditions produce unnatural levels of runoff, such as occurs below roads, the stream beds will exhibit a greater amount of scour, often down to bedrock and banks may be undercut. This process greatly increases watershed erosion and results in thinner soils, upslope from the stream bed, as the channel adjusts to the increase in flow. The stream bed is very complex in terms of erosion. Sediment is transported, eroded and deposited on the stream bed.[2] With global warming there is a fear that the size and shape of riverbeds will change due to increased flood magnitude and frequency. However, one study has shown that the majority of sediment washed out in floods is "near-threshold" sediment that has been deposited during normal flow and only needs a slightly higher flow to become mobile again. This shows that the stream bed is left mostly unchanged in size and shape.[3]

Beds are usually what would be left once a stream is no longer in existence; the beds are usually well preserved even if they get buried, because the walls and canyons made by the stream usually have hard walls, usually soft sand and debris fill the bed. Dry stream beds are also subject to becoming underground water pockets (buried stream beds only) and flooding by heavy rains and water rising from the ground and may sometimes be part of the rejuvenation of the stream.

Low creek
A stream bed armored with rocks

See also

References

  1. ^ Jerolmack, Douglas J.; Mohrig, David (2007). "Conditions for branching in depositional rivers". Geology. 35 (5): 463–466. doi:10.1130/G23308A.1.
  2. ^ Garcia, Marcelo; Parker, Gary (1991). "Entrainment of Bed Sediment into Suspension". Journal of Hydraulic Engineering. 117 (4): 414–435. doi:10.1061/(asce)0733-9429(1991)117:4(414).
  3. ^ Phillips, Colin B.; Jerolmack, Douglas J. (2016). "Self-organization of river channels as a critical filter on climate signals". Science. 352: 694–697. doi:10.1126/science.aad3348.
Aeolis Mensae

Aeolis Mensae is tableland feature in the Aeolis quadrangle of Mars. Its location is centered at 2.9° south latitude and 219.6° west longitude. It is 820 kilometres (510 mi) long and was named after a classical albedo feature name.

Arroyo (creek)

An arroyo (; Spanish: [aˈroʝo], "brook"), also called a wash, is a dry creek, stream bed or gulch that temporarily or seasonally fills and flows after sufficient rain. Flash floods are common in arroyos following thunderstorms.

In Latin America any small river might be called an arroyo, even if it flows continually all year and is never dry.

The terms rambla (Spanish) or wadi (Arabic) are used in Spain, North Africa, and Western Asia. Arroyos provide a water source to desert animals.

The desert dry wash biome is restricted to the arroyos of the southwestern United States.

Bed (disambiguation)

A bed is a piece of furniture.

Bed or beds may also refer to:

Bed (geology)

Garden bed

Hospital beds

Stream bed

De Grey River

The De Grey River is a river located in the Pilbara region of Western Australia. It was named on 16 August 1861 by the explorer and surveyor Francis Gregory after Thomas de Grey, 2nd Earl de Grey who was, at the time, President of the Royal Geographical Society.The river rises south of Callawa at the confluence of the Oakover and the Nullagine rivers and flows in a west-north-westerly direction eventually discharging into the Indian Ocean via Breaker Inlet about 80 km north-east of Port Hedland.

Its stream bed is 100 to 130 metres wide, dry throughout most of the year. The shore's land is rich in grass and fertile, featuring trees.

The river flows through many semi-permanent pools of water on the way to the coast, including Yukerakine Pool, Muccanoo Pool, Talyirina Pool, Wardoomoondener Pool and Triangle Pool.

The river has eleven tributaries, including the Oakover River, Nullagine River, Coongan River, East Strelley River, Shaw River, Miningarra Creek, Egg Creek and Kookenyia Creek.

Degradation (geology)

In geology, degradation refers to the lowering of a fluvial surface, such as a stream bed or floodplain, through erosional processes. Degradation is the opposite of aggradation. Degradation is characteristic of channel networks in which either bedrock erosion is taking place, or in systems that are sediment-starved and are therefore entraining more material than they are depositing. When a stream degrades, it leaves behind a fluvial terrace. This can be further classified as a strath terrace—a bedrock terrace that may have a thin mantle of alluvium—if the river is incising through bedrock. These terraces may be dated with methods such as cosmogenic radionuclide dating, OSL dating, and paleomagnetic dating (using reversals in the Earth's magnetic field to constrain the timing of events) to find when a river was at a particular level and how quickly it is downcutting.

Diana, Princess of Wales Memorial Fountain

The Diana, Princess of Wales Memorial Fountain is a memorial in London dedicated to Diana, Princess of Wales, who died in a car crash in 1997. It was designed to express Diana's spirit and love of children.The fountain is located in the southwest corner of Hyde Park, just south of the Serpentine lake and east of the Serpentine Gallery. Its cornerstone was laid in September 2003 and it was officially opened on 6 July 2004 by Queen Elizabeth II. Also present were Diana's younger brother Charles Spencer, her ex-husband Prince Charles, and her sons William and Harry. The opening ceremony brought the Windsors and the Spencers together for the first time in 7 years.

Gaor Bheinn

Gaor Bheinn, also known as Gulvain or Culvain, is a mountain in Scotland, to the north of the road west of Fort William (from which it is usually climbed), and south of Loch Arkaig. It is composed of banded granite and shaped like a letter Y, with two tops connected by a ridge running from northeast to southwest, with the northern top 6 m higher than the one to the south. Crags drop at either end, and steep slopes fall away to either side.

The south ridge path is really a stream bed, so in wet conditions an easier if longer ascent from Na Socachan is to walk up Allt a Choire Reidh towards Gualann nan Osna and climb the south top's north-west ridge.

Hydraulic action

Hydraulic action is the erosion that occurs when the motion of water against a rock surface produces mechanical weathering. Most generally, it is the ability of moving water (flowing or waves) to dislodge and transport rock particles. Within this rubric are a number of specific erosional processes, including abrasion, attrition, corrasion, saltation, and scouring (downcutting). Hydraulic action is distinguished from other types of water facilitated erosion, such as static erosion where water leaches salts and floats off organic material from unconsolidated sediments, and from chemical erosion more often called chemical weathering.

It is a mechanical process, in which the moving water current flows against the banks and bed of a river, thereby removing rock particles.

A primary example of hydraulic action is a wave striking a cliff face which compresses the air in cracks of the rocks. This exerts pressure on the surrounding rock which can progressively crack, break, splinter and detach rock particles. This is followed by the decompression of the air as the wave retreats which can occur suddenly with explosive force which additionally weakens the rock. Cracks are gradually widened so each wave compresses more air, increasing the explosive force of its release. Thus, the effect intensifies in a 'positive feedback' system. Over time, as the cracks may grow they sometimes form a sea cave. The broken pieces that fall off produce two additional types of erosion, abrasion (sandpapering) and attrition. In corrasion, the newly formed chunks are thrown against the rock face. Attrition is a similar effect caused by eroded particles after they fall to the sea bed where they are subjected to further wave action. In coastal areas wave hydraulic action is often the most important form of erosion.

Similarly, where hydraulic action is strong enough to loosen sediment along a stream bed and its banks; this will take rocks and particles from the banks and bed of the stream and add this to the stream's load. This process is the result of friction between the moving water and the static stream bed and banks. This friction increases with the speed of the water and the roughness of the bed. Once loosened the smaller particles are actually held in suspension by the force of the flowing water, these suspended particles can scour the sides and bottom of the stream. The scouring action produces distinctive markings on streams beds such as ripple marks, fluting, and crescent marks. The larger particles and even large rocks are scooted (dragged) along the bottom in a process known as traction which causes attrition, and are often "bounced" along in a process known as saltation where the force of the water temporarily lifts the rock particle which then crashes back into the bed dislodging other particles.Hydraulic action also occurs as a stream tumbles over a waterfall to crash onto the rocks below. It usually leads to the formation of a plunge pool below the waterfall due in part to corrosion from the stream's load, but more to a scouring action as vortices form in the water as it escapes downstream. Hydraulic action can also cause the breakdown of river banks since there are water bubbles which enter the banks and collapse them when they expand.

Hyporheic zone

The hyporheic zone is a region beneath and alongside a stream bed, where there is mixing of shallow groundwater and surface water. The flow dynamics and behavior in this zone (termed hyporheic flow or underflow) is recognized to be important for surface water/groundwater interactions, as well as fish spawning, among other processes. As an innovative urban water management practice, the hyporheic zone can be designed by engineers and actively managed for improvements in both water quality and riparian habitat.The assemblage of organisms which inhabits this zone are called hyporheos.

The term hyporheic was originally coined by Traian Orghidan in 1959 by combining two Greek words: hypo (below) and rheos (flow).

Little Juniata River

The Little Juniata River, sometimes called the "Little J," is a river that is not owned by anyone person. It is held in trust by the state of Pennsylvania for the people of the state and beyond. Pennsylvania. 32.1-mile-long (51.7 km) tributary of the Juniata River in the Susquehanna River watershed. It is formed at Altoona by the confluence of several short streams. It flows northeast in the Logan Valley at the foot of Brush Mountain.

At Tyrone, the river receives the southern Bald Eagle Creek, then turns abruptly southeast, passing through a water gap between the Brush and Bald Eagle Mountain ridges and enters the Sinking Valley where it receives Sinking Run. Approximately 6 miles (10 km) northwest of Huntingdon, Pennsylvania, near Petersburg, it joins the Frankstown Branch Juniata River, forming the Juniata River.In colonial America, the river was used to float freight downriver on boats called "arcs". Shipments were placed on board in Birmingham, just east of Tyrone to await water high enough to clear the rocky stream bed. Thus the Little Juniata was (and still is) listed as a commercially "Navigable" river.

The Little Juniata River is a good spot for fly fishing; It holds a Class A population of wild brown trout and requires no stocking. Former President of the United States Jimmy Carter fishes often at Spruce Creek, a "j" tributary that enters the "j" at the village of Spruce Creek.

Natural Bridges National Monument

Natural Bridges National Monument is a U.S. National Monument located about 50 miles (80 km) northwest of the Four Corners boundary of southeast Utah, in the western United States, at the junction of White Canyon and Armstrong Canyon, part of the Colorado River drainage. It features the thirteenth largest natural bridge in the world, carved from the white Permian sandstone of the Cedar Mesa Formation that gives White Canyon its name.

The three bridges in the park are named Kachina, Owachomo, and Sipapu (the largest), which are all Hopi names. A natural bridge is formed through erosion by water flowing in the stream bed of the canyon. During periods of flash floods, particularly, the stream undercuts the walls of rock that separate the meanders (or "goosenecks") of the stream, until the rock wall within the meander is undercut and the meander is cut off; the new stream bed then flows underneath the bridge. Eventually, as erosion and gravity enlarge the bridge's opening, the bridge collapses under its own weight. There is evidence of at least two collapsed natural bridges within the Monument.

Patnos Dam

Patnos Dam is a dam in Turkey. The development was backed by the Turkish State Hydraulic Works.

Earth body filler type, the dam body volume of 1.3 million m3, stream bed height 38.00 m., normal water volume of the Lake at 33,40 hm3, normal water is Lake area at 4.35 km2. The dam provides irrigation Service 5.973 hectares.

Perennial stream

A perennial stream or perennial river is a stream or river (channel) that has continuous flow in parts of its stream bed all year round during years of normal rainfall. "Perennial" streams are contrasted with "intermittent" streams which normally cease flowing for weeks or months each year, and with "ephemeral" channels that flow only for hours or days following rainfall. During unusually dry years, a normally perennial stream may cease flowing, becoming intermittent for days, weeks, or months depending on severity of the drought. The boundaries between perennial, intermittent, and ephemeral channels are not defined, and subject to a variety of identification methods adopted by local governments, academics, and others with a need to classify stream-flow permanence.

As stream flow decreases in dry weather, visible flow above the stream bed may not be readily evident, especially in streams with coarse substrate (gravel and rocks), where water is flowing beneath and between these particles (hyporheic flow). From a biological perspective, a stream may be considered flowing if sufficient water is available to support flow-dependent aquatic life, including fish and gill-breathing amphibians, benthic insects, crustaceans, and mollusks, many of which survive in shallow hyporheic flow beneath rocks or logs. This extreme low flow may not be detectable on typical USGS stream-flow gauges, but is vital to stream ecology.

Placer mining

Placer mining is the mining of stream bed (alluvial) deposits for minerals. This may be done by open-pit (also called open-cast mining) or by various surface excavating equipment or tunnelling equipment.

Placer mining is frequently used for precious metal deposits (particularly gold) and gemstones, both of which are often found in alluvial deposits—deposits of sand and gravel in modern or ancient stream beds, or occasionally glacial deposits. The metal or gemstones, having been moved by stream flow from an original source such as a vein, are typically only a minuscule portion of the total deposit. Since gems and heavy metals like gold are considerably more dense than sand, they tend to accumulate at the base of placer deposits.

It is important to note that placer deposits can be as young as a few years old, such as the Canadian Queen Charlotte beach gold placer deposits, or billions of years old like the Elliott Lake uranium paleoplacer within the Huronian Supergroup in Canada.The containing material in an alluvial placer mine may be too loose to safely mine by tunnelling, though it is possible where the ground is permanently frozen. Where water under pressure is available, it may be used to mine, move, and separate the precious material from the deposit, a method known as hydraulic mining, hydraulic sluicing or hydraulicking.

Plunge pool

A plunge pool (or plunge basin or waterfall lake) is a deep depression in a stream bed at the base of a waterfall or shut-in. It is created by the erosional forces of cascading water on the rocks at formation's base where the water impacts. The term may refer to the water occupying the depression, or the depression itself.

Pothole (landform)

The Earth scientists, who study rivers and streams, define a pothole as a smooth, bowl-shaped or cylindrical hollow, generally deeper than wide, found carved into the rocky bed of a watercourse. Other names used for riverine potholes are pot, (stream) kettle, giant's kettle, evorsion, hollow, rock mill, churn hole, eddy mill, and kolk. Although somewhat related to a pothole in origin, a plunge pool (or plunge basin or waterfall lake) is the deep depression in a stream bed at the base of a waterfall; it is created by the erosional forces of turbulence generated by water falling on rocks at a waterfall's base where the water impacts. Potholes are also sometimes referred to as swirlholes. This word was created to avoid confusion with an English term for a vertical or steeply inclined karstic shaft in limestone. However, given widespread usage of this term for a type of fluvial sculpted bedrock landform, pothole is preferred in usage to swirlhole.The term pothole is also used to refer to other types of depressions and basins that differ in origin. For example, some authors refer to panholes found in the Colorado Plateau also as potholes. Other terms used for panholes are gnamma (Australia), opferkessel (German, roughly “sacrificial basin”), armchair hollows, weathering pans (or pits) and solution pans or solution pits. In another case, the term pothole is used to refer to a shallow depression, generally less than 10-acre (4.0 ha) in area that occurs between dunes or on subdued morainic relief on a prairie, as in Minnesota and the Dakotas, and often contains an intermittent pond or marsh that serves as a nesting place for waterfowl.

South Coast Botanic Garden

The South Coast Botanic Garden is a 35 hectare (87 acre) garden in the Palos Verdes Hills, in Palos Verdes, California, United States, about 16 km (10 miles) south of Los Angeles International Airport. It has over 150,000 landscaped plants and trees from approximately 140 families, 700 genera, and 2,000 different species, including flowering fruit trees, Coast Redwoods, Ginkgos and Pittosporum. It is particularly rich in plants from Australia and South Africa. Its gardens include the Water-wise Garden, Herb Garden, English Rose Garden, and Garden of the Senses. A small lake and stream bed attract various birds such as ducks, geese, coots, and herons. Over 300 species of birds have been recorded.

The present garden site was operated as an open pit mine from 1929 until 1956, producing over one million tons of crude diatomite. With declining production, the land was sold in 1957 to the County of Los Angeles for a sanitary landfill, which was in use until 1965. However, starting in 1961, an experiment in land reclamation began when County Board of Supervisors approved a motion establishing 87 acres (35 ha) as the site of the South Coast Botanic Garden, which was ultimately landscaped over 3.5 million tons of refuse, in a classic example of land recycling. The Sanitation District in cooperation with other County agencies carried out initial planning, grading and contouring. Operating responsibilities were given to the Los Angeles County Department of Arboreta and Botanic Gardens. In April 1961, the first large-scale planting took place on completed fill overlooking Rolling Hills Road, with over 40,000 plants donated by individuals, nurseries and the County Arboretum.

The site presents unusual difficulties in gardening. First, its soil is composed almost entirely of diatomaceous earth. Second, because of the diverse nature and thickness of the fill, settling rates vary throughout the garden resulting in frequent irrigation system breakage. Third, heat is caused by decomposition of organic matter below the soil surface, and it is accompanied by the production of gases, primarily carbon dioxide and methane.

Thalweg

In geography and fluvial geomorphology, a thalweg or talweg () is the line of lowest elevation within a valley or watercourse.Under international law, a thalweg is the middle of the primary navigable channel of a waterway that defines the boundary line between states. Also under international law, thalwegs can acquire special significance because disputed river borders are often deemed to run along the river's thalweg.

Uzungöl

Uzungöl (Long Lake), or in the local Romeyka language: Şeraho, is a lake situated to the south of the city of Trabzon, in the Çaykara district of Trabzon Province, Turkey. Uzungöl is also the name of the village on the lake's coast. Over the years, the picturesque lake, its village and the surrounding valley have become popular tourist attractions. The lake is at a distance of 99 km from Trabzon's city center, and 19 km from Çaykara's district center. It was formed by a landslide, which transformed the stream bed into a natural dam, in the valley of the Haldizen Stream.The area is most famous for its natural environment. Located in a valley between high rising mountains, the lake and village at first appear inaccessible. The surrounding mountain forests and fog, occasionally enveloping the lake at night, also add to the scenery.The tourist boom of the recent years has attracted investors, who opened a number of hotels, restaurants, and souvenir shops in the village. The transport infrastructure has also been improved. In 2008, the government built a concrete barrier along the lake's shoreline, so that its waves would not wet the coastal roads around it. This has triggered protests by the locals, as well as ecologists concerned with environmental damage, who stated that it has turned the lake into a giant artificial pool.

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