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81-706: Havasu Creek is the second largest tributary of the Colorado River in Grand Canyon National Park. The drainage basin for Havasu Creek is about 3,000 square miles (7,800 km). It includes the town of Williams, Arizona, and Grand Canyon Village. Havasu Creek starts out above the canyon wall as a small trickle of snow run-off and rain water. This water meanders on the plains above the canyon for about 50 miles (80 km) until it enters Cataract Canyon (also known as Havasu Canyon). It then reaches Havasu Springs, where an underground source feeds

162-467: A few places that are viable for cliff jumping, although caution was necessary. In August 2008, Navajo Falls was completely bypassed by a flood. According to The New York Times : Within 12 hours, several surges of high water roared down the creek, destroying the campground, stranding a Boy Scout troop from New Jersey and setting off a massive mudslide that obliterated Navajo Falls, one of four spectacular canyon waterfalls that attract tourists from around

243-452: A maximum at the apex to zero at a crossing point (straight line), also called an inflection, because the curvature changes direction in that vicinity. The radius of the loop is the straight line perpendicular to the down-valley axis intersecting the sinuous axis at the apex. As the loop is not ideal, additional information is needed to characterize it. The orientation angle is the angle between sinuous axis and down-valley axis at any point on

324-405: A meander because helicoidal flow of water keeps the bank washed clean of loose sand, silt, and sediment and subjects it to constant erosion. As a result, the meander erodes and migrates in the direction of the outside bend, forming the cut bank. As the cut bank is undermined by erosion, it commonly collapses as slumps into the river channel. The slumped sediment, having been broken up by slumping,

405-411: A meander is part of an entrenched river or part of a freely meandering river within a floodplain, the term slip-off slope can refer to two different fluvial landforms that comprise the inner, convex, bank of a meander loop. In case of a freely meandering river on a floodplain, a slip-off slope is the inside, gently sloping bank of a meander on which sediments episodically accumulate to form a point bar as

486-431: A meandering watercourse is termed meander geometry or meander planform geometry. It is characterized as an irregular waveform . Ideal waveforms, such as a sine wave , are one line thick, but in the case of a stream the width must be taken into consideration. The bankfull width is the distance across the bed at an average cross-section at the full-stream level, typically estimated by the line of lowest vegetation. As

567-437: A non-mathematical utility as well. Streams can be placed in categories arranged by it; for example, when the index is between 1 and 1.5 the river is sinuous, but if between 1.5 and 4, then meandering. The index is a measure also of stream velocity and sediment load, those quantities being maximized at an index of 1 (straight). Rock shelter A rock shelter (also rockhouse , crepuscular cave , bluff shelter , or abri )

648-428: A river meanders. This type of slip-off slope is located opposite the cutbank. This term can also be applied to the inside, sloping bank of a meandering tidal channel. In case of an entrenched river, a slip-off slope is a gently sloping bedrock surface that rises from the inside, concave bank of an asymmetrically entrenched river. This type of slip-off slope is often covered by a thin, discontinuous layer of alluvium. It

729-528: A river to meander, secondary flow must dominate. Irrotational flow : From Bernoulli's equations, high pressure results in low velocity. Therefore, in the absence of secondary flow we would expect low fluid velocity at the outside bend and high fluid velocity at the inside bend. This classic fluid mechanics result is irrotational vortex flow. In the context of meandering rivers, its effects are dominated by those of secondary flow. Secondary flow : A force balance exists between pressure forces pointing to

810-435: A rope had been placed for climbing a rock wall in order to further traverse the trail down the canyon. This has now been replaced with a much more navigable ladder. Farther downstream, a rock chute/slide provides one access to Beaver Falls. Easier access is further along, just before the trail turns north to continue down the canyon. River rafters have beaten a path to the ledges where they jump. Turning upstream from here, it

891-413: A self-intensifying process...in which greater curvature results in more erosion of the bank, which results in greater curvature..." The cross-current along the floor of the channel is part of the secondary flow and sweeps dense eroded material towards the inside of the bend. The cross-current then rises to the surface near the inside and flows towards the outside, forming the helical flow . The greater

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972-509: A short time as to create civil engineering challenges for local municipalities attempting to maintain stable roads and bridges. The degree of meandering of the channel of a river, stream, or other watercourse is measured by its sinuosity . The sinuosity of a watercourse is the ratio of the length of the channel to the straight line down-valley distance. Streams or rivers with a single channel and sinuosities of 1.5 or more are defined as meandering streams or rivers. The term derives from

1053-419: A small stream feeds into the creek, over the side of the cliff, effectively creating a place to shower. The trail leads to the right towards the creek, then back towards Mooney Falls to get to this mini-waterfall. The next 3–4 mi (5–6 km) are remote and rugged. The trail is not always easy to follow and requires multiple crossings of the creek. At one point, after a large, oddly out of place palm tree,

1134-434: A symmetrical valley sides. He argues that the symmetrical valley sides are the direct result of rapid down-cutting of a watercourse into bedrock. In addition, as proposed by Rich, Thornbury argues that incised valleys with a pronounced asymmetry of cross section, which he called ingrown meanders , are the result of the lateral migration and incision of a meander during a period of slower channel downcutting . Regardless,

1215-417: A very rugged and dangerous descent is required. Extreme care and discretion for the following portion is required; it is highly exposed and should not be attempted when the weather and/or conditions are not suitable. The trail down is located on the left side (looking downstream), up against the canyon wall. The first half of the trail is only moderately difficult until the entrance of a small passageway/cave

1296-413: A waveform the meandering stream follows the down-valley axis, a straight line fitted to the curve such that the sum of all the amplitudes measured from it is zero. This axis represents the overall direction of the stream. At any cross-section the flow is following the sinuous axis, the centerline of the bed. Two consecutive crossing points of sinuous and down-valley axes define a meander loop. The meander

1377-431: Is a shallow cave -like opening at the base of a bluff or cliff . In contrast to solutional caves ( karst ), which are often many miles long or wide, rock shelters are almost always modest in size and extent. Rock shelters form because a rock stratum such as sandstone that is resistant to erosion and weathering has formed a cliff or bluff, but a softer stratum, more subject to erosion and weathering, lies just below

1458-419: Is called lateral accretion. Lateral accretion occurs mostly during high water or floods when the point bar is submerged. Typically, the sediment consists of either sand, gravel, or a combination of both. The sediment comprising some point bars might grade downstream into silty sediments. Because of the decreasing velocity and strength of current from the thalweg of the channel to the upper surface of point bar when

1539-583: Is long, difficult, and rugged, and it is advisable only for experienced hikers. The creek ends at the confluence, where there are some camping areas. This spot is also popular for river rafters to stop and to head up the canyon. Flooding is common along Havasu Creek. A government report lists 14 "historic floods" from 1899 to 1993. One such flood occurred on August 17, 2008, when the Redlands Dam on Havasu Creek burst after days of heavy rain. The floodwaters' threat to human life led local authorities to evacuate

1620-435: Is possible to gradually get to the creek bed and follow it further upstream to the falls. The pools here are small, but still offer good swimming. Beaver Falls was once much more impressive. It had a height of about fifty feet in one fall, at the junction of Beaver Canyon and Havasu Canyon. The great flood of January 1910 destroyed it, leaving the falls over the limestone ledges as they are today. Rotted cottonwood logs near

1701-424: Is produced by the gradual outward migration of the meander as a river cuts downward into bedrock. A terrace on the slip-off slope of a meander spur, known as slip-off slope terrace , can be formed by a brief halt during the irregular incision by an actively meandering river. The meander ratio or sinuosity index is a means of quantifying how much a river or stream meanders (how much its course deviates from

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1782-414: Is reached. At this point the trail becomes very difficult and very precarious. The small passageway is large enough for the average human, and leads to a small opening in which another passageway is entered. At the end of the second passageway the trail becomes a semi-vertical rock climb that is similar to descending a ladder. Strategically placed chains, handholds, and ladders aid in the climb. Mist from

1863-458: Is readily eroded and carried toward the middle of the channel. The sediment eroded from a cut bank tends to be deposited on the point bar of the next downstream meander, and not on the point bar opposite it. This can be seen in areas where trees grow on the banks of rivers; on the inside of meanders, trees, such as willows, are often far from the bank, whilst on the outside of the bend, the tree roots are often exposed and undercut, eventually leading

1944-494: Is seldom a significant factor. Many rock shelters are found under waterfalls . Rock shelters are often important archaeologically . Because rock shelters form natural shelters from the weather, prehistoric humans often used them as living-places, and left behind debris, tools, and other artifacts . In mountainous areas the shelters can also be important for mountaineers . Transhumant nomads, people who move with their livestock - often from lower permanent winter residences in

2025-484: Is the Büyük Menderes River . Meanders are a result of the interaction of water flowing through a curved channel with the underlying river bed. This produces helicoidal flow , in which water moves from the outer to the inner bank along the river bed, then flows back to the outer bank near the surface of the river. This in turn increases carrying capacity for sediments on the outer bank and reduces it on

2106-478: Is the length along the centerline. Once a channel begins to follow a sinusoidal path, the amplitude and concavity of the loops increase dramatically. This is due to the effect of helical flow which sweeps dense eroded material towards the inside of the bend, and leaves the outside of the bend unprotected and vulnerable to accelerated erosion. This establishes a positive feedback loop . In the words of Elizabeth A. Wood: "...this process of making meanders seems to be

2187-405: Is the most common type of fluvial lake, is a crescent-shaped lake that derives its name from its distinctive curved shape. Oxbow lakes are also known as cutoff lakes . Such lakes form regularly in undisturbed floodplains as a result of the normal process of fluvial meandering. Either a river or stream forms a sinuous channel as the outer side of its bends are eroded away and sediments accumulate on

2268-430: Is two consecutive loops pointing in opposite transverse directions. The distance of one meander along the down-valley axis is the meander length or wavelength . The maximum distance from the down-valley axis to the sinuous axis of a loop is the meander width or amplitude . The course at that point is the apex. In contrast to sine waves, the loops of a meandering stream are more nearly circular. The curvature varies from

2349-425: Is typically a point bar . The result of this coupled erosion and sedimentation is the formation of a sinuous course as the channel migrates back and forth across the axis of a floodplain . The zone within which a meandering stream periodically shifts its channel is known as a meander belt . It typically ranges from 15 to 18 times the width of the channel. Over time, meanders migrate downstream, sometimes in such

2430-524: The Colorado River . Until the August 2008 flooding, Navajo Falls was the first prominent waterfall in the canyon. They were named after an old Supai chief . It was located 1.25 miles (2 km) from Supai and is accessed from a trail located on the left side (right side when heading upstream) of the main trail. This side trail leads down to the creek, where there is a crude bridge that crosses over

2511-483: The Ozark Plateau . As noted above, it was initially either argued or presumed that an incised meander is characteristic of an antecedent stream or river that had incised its channel into underlying strata . An antecedent stream or river is one that maintains its original course and pattern during incision despite the changes in underlying rock topography and rock types. However, later geologists argue that

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2592-449: The bedrock are known as either incised , intrenched , entrenched , inclosed or ingrown meanders . Some Earth scientists recognize and use a finer subdivision of incised meanders. Thornbury argues that incised or inclosed meanders are synonyms that are appropriate to describe any meander incised downward into bedrock and defines enclosed or entrenched meanders as a subtype of incised meanders (inclosed meanders) characterized by

2673-469: The geomorphological feature. Strabo said: ‘...its course is so exceedingly winding that everything winding is called meandering.’ The Meander River is south of Izmir, east of the ancient Greek town of Miletus , now Milet, Turkey. It flows through series of three graben in the Menderes Massif, but has a flood plain much wider than the meander zone in its lower reach. Its modern Turkish name

2754-430: The aforementioned junction show how high the water rose during that flood. Frequent flooding changes the appearance of some waterfalls and causes others to appear and disappear. Navajo Falls (above) is one such example. The creek flows to the Colorado River from Beaver Falls. There are multiple ways to reach the river, including going back up the chute to the trail and continuing downstream. The 3 miles (5 km) hike

2835-416: The area. A small man-made dam was constructed to help restore the pools and to preserve what is left. There are many picnic tables on the opposite side of the creek and it is very easy to cross over by following the edges of the pools. It is possible to swim behind the falls and enter a small rock shelter behind it. Before the flood of 1910, the falls were called "Bridal Veil Falls" because they fell from

2916-411: The average fullbank channel width. The length of the stream is measured by channel, or thalweg, length over the reach, while the bottom value of the ratio is the downvalley length or air distance of the stream between two points on it defining the reach. The sinuosity index plays a part in mathematical descriptions of streams. The index may require elaboration, because the valley may meander as well—i.e.,

2997-554: The bottom from the outside to the inside. The flow is supplied by a counter-flow across the surface from the inside to the outside. This entire situation is very similar to the Tea leaf paradox . This secondary flow carries sediment from the outside of the bend to the inside making the river more meandering. As to why streams of any size become sinuous in the first place, there are a number of theories, not necessarily mutually exclusive. The stochastic theory can take many forms but one of

3078-429: The boundary layer. Therefore, within the boundary layer, pressure force dominates and fluid moves along the bottom of the river from the outside bend to the inside bend. This initiates helicoidal flow: Along the river bed, fluid roughly follows the curve of the channel but is also forced toward the inside bend; away from the river bed, fluid also roughly follows the curve of the channel but is forced, to some extent, from

3159-420: The canyon. It is located at 36°15′18″N 112°41′52″W  /  36.25500°N 112.69778°W  / 36.25500; -112.69778 (1.5 mi (2.4 km) from Supai) and is accessed from a trail on the right side (left side when heading upstream) of the main trail. The side trail leads across a small plateau and drops into the main pool. Havasu is arguably the most famous and most visited of all

3240-559: The case of the Anderson Bottom Rincon, incised meanders that have either steep-sided, often vertical walls, are often, but not always, known as rincons in the southwest United States . Rincon in English is a nontechnical word in the southwest United States for either a small secluded valley, an alcove or angular recess in a cliff, or a bend in a river. The meanders of a stream or river that has cut its bed down into

3321-410: The creek and reflects its color so strongly. This also gives the creek an interesting feature, as it is ever-changing. This occurs because any items that fall into the stream mineralize very quickly, causing new formations and changing the flow of the water. This causes the creek to never look the same from one year to another. The creek runs through the village of Supai , and it ultimately flows into

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3402-462: The creek. The trail then leads back into the trees, where the main pool and falls were located. The pool was popular for its seclusion and its ease to swimmers. The falls were approximately 70 feet (20 m) tall and consisted of separate sets of water chutes, the main one located on the right side where the water cascaded down the canyon hill. To the left of the main chute there were other smaller ones that were steeper and more vertical. There were

3483-405: The creek. This spring can be accessed by heading upstream when the creek is first encountered. Water temperature varies from the low seventies during the warmer half of the year, to the mid-fifties in winter. The creek is well known for its blue-green color and distinctive travertine formations. This is due to large amounts of calcium carbonate in the water that formed the limestone that lines

3564-408: The curvature of the bend, and the faster the flow, the stronger is the cross-current and the sweeping. Due to the conservation of angular momentum the speed on the inside of the bend is faster than on the outside. Since the flow velocity is diminished, so is the centrifugal pressure. The pressure of the super-elevated column prevails, developing an unbalanced gradient that moves water back across

3645-405: The downvalley length is not identical to the reach. In that case the valley index is the meander ratio of the valley while the channel index is the meander ratio of the channel. The channel sinuosity index is the channel length divided by the valley length and the standard sinuosity index is the channel index divided by the valley index. Distinctions may become even more subtle. Sinuosity Index has

3726-423: The entire width of the now-dry travertine cliffs north and south of the present falls. Mooney Falls is the fourth main waterfall in the canyon. It is named after D. W. "James" Mooney, a miner , who in 1882 – according to his companions – decided to mine the area near Havasu Falls for minerals. The group then decided to try Mooney Falls. One of his companions was injured, so James Mooney decided to try to climb up

3807-438: The falls often makes the rock slippery, and the climb is also difficult because of having to pass people going in the opposite direction. The pool is the largest of the three, and some people jump from low cliff ledges into the pool. It is possible for strong swimmers to swim to the left of the falls to the rock wall and then to a small cave that is located just above the water line, approximately 15–20 feet (5 to 6 meters) away from

3888-404: The falls with his companion tied to his back, and subsequently fell to his death. The Falls are located 2.25 miles (3.6 km) from Supai, just past the campgrounds. The trail leads to the top of the falls, where there is a lookout/photograph area that overlooks the 210-foot (64 m) canyon wall that the waterfall cascades over. In order to gain access to the bottom of the falls and its pool,

3969-449: The falls. An island breaks the pool into two streams. Beaver Falls is arguably the fifth set of falls, although many claim that it is not a waterfall, but merely a set of small falls that are located close to each other. The falls are located approximately 6 miles (10 km) downstream of Supai, and are the most difficult to access. After the descent to Mooney Falls, a visible trail leads downstream. About 0.25 miles (400 m) down,

4050-438: The falls. The falls consist of one main chute that drops over a 100-foot (30 m) vertical cliff (due to the high mineral content of the water, the falls are ever-changing and sometimes break into two separate chutes of water) into a large pool. The falls are known for their natural pools, created by mineralization, although most of these pools were damaged and/or destroyed in the early 1990s by large floods that washed through

4131-565: The formation of both entrenched meanders and ingrown meanders is thought to require that base level falls as a result of either relative change in mean sea level , isostatic or tectonic uplift, the breach of an ice or landslide dam, or regional tilting. Classic examples of incised meanders are associated with rivers in the Colorado Plateau , the Kentucky River Palisades in central Kentucky , and streams in

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4212-428: The full force of the flood. After a cutoff meander is formed, river water flows into its end from the river builds small delta-like feature into either end of it during floods. These delta-like features block either end of the cutoff meander to form a stagnant oxbow lake that is separated from the flow of the fluvial channel and independent of the river. During floods, the flood waters deposit fine-grained sediment into

4293-404: The fullbank channel width and 3 to 5 times, with an average of 4.7 times, the radius of curvature at the apex. This radius is 2–3 times the channel width. A meander has a depth pattern as well. The cross-overs are marked by riffles , or shallow beds, while at the apices are pools. In a pool direction of flow is downward, scouring the bed material. The major volume, however, flows more slowly on

4374-407: The inner bank, so that sediments are eroded from the outer bank and redeposited on the inner bank of the next downstream meander. When a fluid is introduced to an initially straight channel which then bends, the sidewalls induce a pressure gradient that causes the fluid to alter course and follow the bend. From here, two opposing processes occur: (1) irrotational flow and (2) secondary flow . For

4455-416: The inner side, which forms a meandering horseshoe-shaped bend. Eventually as the result of its meandering, the fluvial channel cuts through the narrow neck of the meander and forms a cutoff meander. The final break-through of the neck, which is called a neck cutoff , often occurs during a major flood because that is when the watercourse is out of its banks and can flow directly across the neck and erode it with

4536-443: The inside bank of a river bend. On the inside bend, this sediment and debris is eventually deposited on the slip-off slope of a point bar. Scroll-bars are a result of continuous lateral migration of a meander loop that creates an asymmetrical ridge and swale topography on the inside of the bends. The topography is generally parallel to the meander, and is related to migrating bar forms and back bar chutes, which carve sediment from

4617-467: The inside bend of the river and centrifugal forces pointing to the outside bend of the river. In the context of meandering rivers, a boundary layer exists within the thin layer of fluid that interacts with the river bed. Inside that layer and following standard boundary-layer theory, the velocity of the fluid is effectively zero. Centrifugal force, which depends on velocity, is also therefore effectively zero. Pressure force, however, remains unaffected by

4698-406: The inside of the bend where, due to decreased velocity, it deposits sediment. The line of maximum depth, or channel, is the thalweg or thalweg line. It is typically designated the borderline when rivers are used as political borders. The thalweg hugs the outer banks and returns to center over the riffles. The meander arc length is the distance along the thalweg over one meander. The river length

4779-450: The inside to the outside bend. The higher velocities at the outside bend lead to higher shear stresses and therefore result in erosion. Similarly, lower velocities at the inside bend cause lower shear stresses and deposition occurs. Thus meander bends erode at the outside bend, causing the river to becoming increasingly sinuous (until cutoff events occur). Deposition at the inside bend occurs such that for most natural meandering rivers,

4860-420: The meanders are fixed. Various mathematical formulae relate the variables of the meander geometry. As it turns out some numerical parameters can be established, which appear in the formulae. The waveform depends ultimately on the characteristics of the flow but the parameters are independent of it and apparently are caused by geologic factors. In general the meander length is 10–14 times, with an average 11 times,

4941-418: The more heterogeneous braided river deposits. There are two distinct patterns of scroll-bar depositions; the eddy accretion scroll bar pattern and the point-bar scroll pattern. When looking down the river valley they can be distinguished because the point-bar scroll patterns are convex and the eddy accretion scroll bar patterns are concave. Scroll bars often look lighter at the tops of the ridges and darker in

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5022-504: The most general statements is that of Scheidegger: "The meander train is assumed to be the result of the stochastic fluctuations of the direction of flow due to the random presence of direction-changing obstacles in the river path." Given a flat, smooth, tilted artificial surface, rainfall runs off it in sheets, but even in that case adhesion of water to the surface and cohesion of drops produce rivulets at random. Natural surfaces are rough and erodible to different degrees. The result of all

5103-474: The most unstable waterfall in Havasu Canyon since 1885, disappearing and reappearing several times. The most recent reappearance was in 1970. This waterfall, also called Rock Falls, was created by the 2008 flood, about 0.15 miles (240 m) below Fiftyfoot Falls. The creek falls about 30 feet (10 m) into a swimming hole. Havasu Falls ( Havasupai : Havasuw Hagjahgeevma ) is the third waterfall in

5184-529: The outside of the curve and deposit sediment in the slower flowing water on the inside of the loop, in a process called lateral accretion. Scroll-bar sediments are characterized by cross-bedding and a pattern of fining upward. These characteristics are a result of the dynamic river system, where larger grains are transported during high energy flood events and then gradually die down, depositing smaller material with time (Batty 2006). Deposits for meandering rivers are generally homogeneous and laterally extensive unlike

5265-415: The oxbow lake. As a result, oxbow lakes tend to become filled in with fine-grained, organic-rich sediments over time. A point bar , which is also known as a meander bar , is a fluvial bar that is formed by the slow, often episodic, addition of individual accretions of noncohesive sediment on the inside bank of a meander by the accompanying migration of the channel toward its outer bank. This process

5346-475: The physical factors acting at random is channels that are not straight, which then progressively become sinuous. Even channels that appear straight have a sinuous thalweg that leads eventually to a sinuous channel. In the equilibrium theory, meanders decrease the stream gradient until an equilibrium between the erodibility of the terrain and the transport capacity of the stream is reached. A mass of water descending must give up potential energy , which, given

5427-407: The resistant stratum, and thus undercuts the cliff. In arid areas, wind erosion ( Aeolian erosion ) can be an important factor in rockhouse formation. In most humid areas, the most important factor in rockhouse formation is frost spalling , where the softer, more porous rock underneath is pushed off, tiny pieces at a time, by frost expansion from water frozen in the pores. Erosion from moving water

5508-691: The river width remains nearly constant, even as the river evolves. In a speech before the Prussian Academy of Sciences in 1926, Albert Einstein suggested that because the Coriolis force of the earth can cause a small imbalance in velocity distribution, such that velocity on one bank is higher than on the other, it could trigger the erosion on one bank and deposition of sediment on the other that produces meanders However, Coriolis forces are likely insignificant compared with other forces acting to produce river meanders. The technical description of

5589-416: The same velocity at the end of the drop as at the beginning, is removed by interaction with the material of the stream bed. The shortest distance; that is, a straight channel, results in the highest energy per unit of length, disrupting the banks more, creating more sediment and aggrading the stream. The presence of meanders allows the stream to adjust the length to an equilibrium energy per unit length in which

5670-417: The sediment is deposited the vertical sequence of sediments comprising a point bar becomes finer upward within an individual point bar. For example, it is typical for point bars to fine upward from gravel at the base to fine sands at the top. The source of the sediment is typically upstream cut banks from which sand, rocks and debris has been eroded, swept, and rolled across the bed of the river and downstream to

5751-505: The shape of an incised meander is not always, if ever, "inherited", e.g., strictly from an antecedent meandering stream where its meander pattern could freely develop on a level floodplain. Instead, they argue that as fluvial incision of bedrock proceeds, the stream course is significantly modified by variations in rock type and fractures , faults , and other geological structures into either lithologically conditioned meanders or structurally controlled meanders . The oxbow lake , which

5832-445: The shortest possible path). It is calculated as the length of the stream divided by the length of the valley . A perfectly straight river would have a meander ratio of 1 (it would be the same length as its valley), while the higher this ratio is above 1, the more the river meanders. Sinuosity indices are calculated from the map or from an aerial photograph measured over a distance called the reach , which should be at least 20 times

5913-411: The sinuous axis. A loop at the apex has an outer or concave bank and an inner or convex bank. The meander belt is defined by an average meander width measured from outer bank to outer bank instead of from centerline to centerline. If there is a flood plain , it extends beyond the meander belt. The meander is then said to be free—it can be found anywhere in the flood plain. If there is no flood plain,

5994-419: The stream carries away all the sediment that it produces. Geomorphic refers to the surface structure of the terrain. Morphotectonic means having to do with the deeper, or tectonic (plate) structure of the rock. The features included under these categories are not random and guide streams into non-random paths. They are predictable obstacles that instigate meander formation by deflecting the stream. For example,

6075-403: The stream might be guided into a fault line (morphotectonic). A cut bank is an often vertical bank or cliff that forms where the outside, concave bank of a meander cuts into the floodplain or valley wall of a river or stream. A cutbank is also known either as a river-cut cliff , river cliff , or a bluff and spelled as cutbank . Erosion that forms a cut bank occurs at the outside bank of

6156-416: The swales. This is because the tops can be shaped by wind, either adding fine grains or by keeping the area unvegetated, while the darkness in the swales can be attributed to silts and clays washing in during high water periods. This added sediment in addition to water that catches in the swales is in turn is a favorable environment for vegetation that will also accumulate in the swales. Depending upon whether

6237-406: The trees to fall into the river. A meander cutoff , also known as either a cutoff meander or abandoned meander , is a meander that has been abandoned by its stream after the formation of a neck cutoff. A lake that occupies a cutoff meander is known as an oxbow lake . Cutoff meanders that have cut downward into the underlying bedrock are known in general as incised cutoff meanders . As in

6318-464: The valleys to higher summer pastures - frequently build semi-permanent camps, often of rocks. In western Connecticut and eastern New York , many rock shelters are known by the colloquialism "leatherman caves", as they were inhabited by the Leatherman over three decades in the late 19th century. The Cumberland stitchwort ( Minuartia cumberlandensis ) is an endangered species of plant which

6399-476: The village. Rescue crews airlifted about 400 people to safety. Navajo Falls was bypassed in the flooding, Fiftyfoot Falls became more prominent, and Lower Navajo Falls was formed. Meander A meander is one of a series of regular sinuous curves in the channel of a river or other watercourse . It is produced as a watercourse erodes the sediments of an outer, concave bank ( cut bank or river cliff ) and deposits sediments on an inner, convex bank which

6480-603: The winding river Menderes located in Asia-Minor and known to the Ancient Greeks as Μαίανδρος Maiandros ( Latin : Maeander ), characterised by a very convoluted path along the lower reach. As a result, even in Classical Greece (and in later Greek thought) the name of the river had become a common noun meaning anything convoluted and winding, such as decorative patterns or speech and ideas, as well as

6561-413: The world. Despite this early report, the site of the falls still exists; the mudslide simply rerouted Havasu Creek. This waterfall, also called Upper Navajo Falls, became more prominent in the 2008 flood that bypassed Navajo Falls, and is now the first waterfall in the canyon. The falls are about 50 feet (15 m) tall and fall into a rocky pool. Originally known as Supai Falls, this waterfall has been

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