A meander is one of a series of regular sinuous curves, loops, turns, or windings in the channel of a river, stream, or other watercourse. It is produced by a stream or river swinging from side to side as it flows across its floodplain or shifts its channel within a valley. A meander is produced by a stream or river as it erodes the sediments comprising an outer, concave bank and deposits this and other sediment downstream on an inner, convex bank, a point bar; the result of sediments being eroded from the outside concave bank and their deposition on an inside convex bank is the formation of a sinuous course as a channel migrates back and forth across the down-valley axis of a floodplain. The zone within which a meandering stream shifts its channel across either its floodplain or valley floor from time to time is known as a meander belt, it ranges from 15 to 18 times the width of the channel. Over time, meanders migrate downstream, sometimes in such a short time as to create civil engineering problems 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 the Meander River located in present-day Turkey and known to the Ancient Greeks as Μαίανδρος Maiandros, characterised by a convoluted path along the lower reach; as a result in Classical Greece 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 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 a graben in the Menderes Massif, but has a flood plain much wider than the meander zone in its lower reach.
Its modern Turkish name is the Büyük Menderes River. When a fluid is introduced to an straight channel which bends, the sidewalls induce a pressure gradient that causes the fluid to alter course and follow the bend. From here, two opposing processes occur: secondary flow. For 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 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 zero.
Centrifugal force, which depends on velocity, is therefore zero. Pressure force, remains unaffected by 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 follows the curve of the channel but is forced toward the inside bend. The higher velocities at the outside bend lead to higher shear stresses and therefore result in erosion. Lower velocities at the inside bend cause lower sheer stresses and deposition occurs, thus meander bends erode at the outside bend, causing the river to becoming sinuous. Deposition at the inside bend occurs such that for most natural meandering rivers, the river width remains nearly constant as the river evolves. Where the river is not forced to bend by a natural obstacle, 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.
This can trigger deposition of sediment on the other. The technical description of 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 estimated by the line of lowest vegetation. As 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 centerline of the bed. Two consecutive crossing points of sinuous and down-valley axes define a meander loop; the meander is two consecutive loops pointing in opposite transverse directions. The distance of one meander along the down-valley axis is 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
The 2011 Toyota/Save Mart 350 was a NASCAR Sprint Cup Series stock car race held on June 26, 2011, at Infineon Raceway in Sonoma, California. Contested over 110 laps, it was the sixteenth race of the 2011 Sprint Cup Series season and the first of two road course competitions on the schedule; the race was won by Kurt Busch for the Penske Racing team. Jeff Gordon finished second, Carl Edwards clinched third. There were five cautions and 13 lead changes among 9 different drivers throughout the course of the race, Kurt Busch's first win of the season; the result moved Kurt Busch to the fourth position in the Drivers' Championship. He remained 34 points behind three ahead of Kyle Busch in seventh. In the Manufacturers' Championship, Chevrolet was leading with 108 points, 15 points ahead Ford and 24 ahead of Toyota. Dodge was fourth on 67 points with 20 races remaining in the season. Prior to the race, Carl Edwards led the Drivers' Championship with 532 points, Kevin Harvick stood in second with 512 points.
Dale Earnhardt, Jr. was third in the Drivers' Championship with 505 points in a Chevrolet, Kyle Busch was fourth with 503 points, Jimmie Johnson was in fifth with 503 points. In the Manufacturers' Championship, Chevrolet was leading with 102 points, 13 points ahead of Ford. Toyota, with 81 points, was 23 ahead of Dodge in the battle for third. Infineon Raceway is one of two road courses to hold NASCAR races, the other being Watkins Glen International; the standard road course at Infineon Raceway is a 12-turn course, 2.52 miles long. The Chute was only used for NASCAR events such as this race, was criticized by many drivers, who preferred the full layout. In 2001, it was replaced with a 70-degree turn, 4A, bringing the track to its current dimensions of 1.99 miles. Three practice sessions were held before the Sunday race—one on Friday, two on Saturday; the first session lasted 90 minutes. The Saturday afternoon session lasted 45 minutes, the evening session lasted 75 minutes. In the first practice session, Kurt Busch was the quickest, leading Denny Hamlin, Kasey Kahne, Kevin Harvick, Martin Truex, Jr. who were in second, third and fifth, respectively.
During qualifying, forty-four cars were entered, but only forty-three were able to race because of NASCAR's qualifying procedure. Joey Logano clinched his second career pole position, with a time of 1:16.82. He was joined on the front row of the grid by Jamie McMurray. Paul Menard qualified third, Hamlin took fourth, Ryan Newman started fifth; the driver that failed to qualify was Tony Ave. In the second practice session, McMurray was the fastest with a fastest lap time of 1:17.62, less than two-tenths of a second quicker than second-placed Kurt Busch. Clint Bowyer took third place, ahead of fourth-placed Kyle Busch and A. J. Allmendinger; the Saturday evening session was held around the same time of day. Brad Keselowski was the quickest, posting a time of 1:18.10, narrowly faster than both McMurray in second and Kurt Busch in third. Juan Pablo Montoya and Bowyer, rounded out the top five positions
New Zealand at the 1930 British Empire Games was represented by a team of 22 competitors and three officials. Team selection for the Games in Hamilton, Canada, was the responsibility of the New Zealand Olympic and British Empire Games Association. New Zealand's flagbearer at the opening ceremony was Stan Lay; these were the first British Empire Games, although in 1911 there was an Empire sports competition at the Festival of Empire in London. New Zealand has competed in every games since; the following table lists the number of New Zealand competitors participating at the Games per sport/discipline. Chef de Mission: Rex Hobbs Chaperone: Jane Pidgeon Rowing coach: Harry Ayres New Zealand Olympic Committee New Zealand at the Commonwealth Games New Zealand at the 1928 Summer Olympics New Zealand at the 1932 Summer Olympics Ron Palenski & Terry Maddaford: The Games Auckland: Moa Publications Ltd. ISBN 0-908570-62-7 NZOC website on the 1930 games Commonwealth Games Federation website Athletes in the 1966 Encyclopaedia of New Zealand has a paragraph on these Games