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111-403: 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 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

222-637: A Collegium medico-chirurgicum in 1723; a botanical garden in 1718; and a laboratory in 1753. However, those were later taken over by the University of Berlin . As a French-language institution its publications were in French such as the Histoire de l'Académie royale des sciences et belles lettres de Berlin which was published between 1745 and 1796. A linguistics historian from Princeton University , Hans Aarsleff , notes that before Frederick ascended

333-453: A Royal charter in 1828, formally recognising civil engineering as a profession. Its charter defined civil engineering as: the art of directing the great sources of power in nature for the use and convenience of man, as the means of production and of traffic in states, both for external and internal trade, as applied in the construction of roads, bridges, aqueducts, canals, river navigation and docks for internal intercourse and exchange, and in

444-520: A chartered engineer (in most Commonwealth countries), a chartered professional engineer (in Australia and New Zealand ), or a European engineer (in most countries of the European Union ). There are international agreements between relevant professional bodies to allow engineers to practice across national borders. The benefits of certification vary depending upon location. For example, in

555-505: A bachelor's degree in engineering represents the first step towards professional certification , and a professional body certifies the degree program. After completing a certified degree program, the engineer must satisfy a range of requirements including work experience and exam requirements before being certified. Once certified, the engineer is designated as a professional engineer (in the United States, Canada and South Africa),

666-587: A few topics, the Prussian Academy was the first to teach both sciences and humanities. In 1710, the Academy statute was set, dividing the Academy into two sciences and two humanities classes. This was not changed until 1830, when the physics-mathematics and the philosophy-history classes replaced the four old classes. The reign of King Frederick II of Prussia ("Frederick the Great") saw major changes to

777-414: A licensed land surveyor are generally required for boundary surveys (to establish the boundaries of a parcel using its legal description) and subdivision plans (a plot or map based on a survey of a parcel of land, with boundary lines drawn inside the larger parcel to indicate the creation of new boundary lines and roads), both of which are generally referred to as Cadastral surveying . Construction surveying

888-452: 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

999-403: 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,

1110-411: 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

1221-430: 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

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1332-441: 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). Civil engineering Civil engineering is a professional engineering discipline that deals with

1443-402: A number of sub-disciplines within the broad field of civil engineering. General civil engineers work closely with surveyors and specialized civil engineers to design grading, drainage, pavement , water supply, sewer service, dams, electric and communications supply. General civil engineering is also referred to as site engineering, a branch of civil engineering that primarily focuses on converting

1554-426: 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

1665-602: 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 winding river Menderes located in Asia-Minor and known to the Ancient Greeks as Μαίανδρος Maiandros ( Latin : Maeander ), characterised by

1776-411: 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

1887-431: 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,

1998-455: A tract of land from one usage to another. Site engineers spend time visiting project sites, meeting with stakeholders, and preparing construction plans. Civil engineers apply the principles of geotechnical engineering, structural engineering, environmental engineering, transportation engineering and construction engineering to residential, commercial, industrial and public works projects of all sizes and levels of construction. Coastal engineering

2109-483: 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 the geomorphological feature. Strabo said: ‘...its course is so exceedingly winding that everything winding is called meandering.’ The Meander River

2220-413: 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

2331-455: Is a discipline that promotes using systems thinking to manage complexity and change in civil engineering within its broader public context. It posits that the proper development of civil engineering infrastructure requires a holistic , coherent understanding of the relationships between all of the crucial factors that contribute to successful projects while at the same time emphasizing the importance of attention to technical detail. Its purpose

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2442-468: Is a sub-discipline of structural engineering. The main objectives of earthquake engineering are to understand interaction of structures on the shaky ground; foresee the consequences of possible earthquakes; and design, construct and maintain structures to perform at earthquake in compliance with building codes . Environmental engineering is the contemporary term for sanitary engineering , though sanitary engineering traditionally had not included much of

2553-419: 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

2664-628: Is closely related to civil engineering. It studies fundamental characteristics of materials, and deals with ceramics such as concrete and mix asphalt concrete, strong metals such as aluminum and steel, and thermosetting polymers including polymethylmethacrylate (PMMA) and carbon fibers. Materials engineering involves protection and prevention (paints and finishes). Alloying combines two types of metals to produce another metal with desired properties. It incorporates elements of applied physics and chemistry . With recent media attention on nanoscience and nanotechnology , materials engineering has been at

2775-857: Is concerned with managing coastal areas. In some jurisdictions, the terms sea defense and coastal protection mean defense against flooding and erosion, respectively. Coastal defense is the more traditional term, but coastal management has become popular as well. Construction engineering involves planning and execution, transportation of materials, and site development based on hydraulic, environmental, structural, and geotechnical engineering. As construction firms tend to have higher business risk than other types of civil engineering firms, construction engineers often engage in more business-like transactions, such as drafting and reviewing contracts, evaluating logistical operations , and monitoring supply prices. Earthquake engineering involves designing structures to withstand hazardous earthquake exposures. Earthquake engineering

2886-445: Is concerned with municipal infrastructure. This involves specifying, designing, constructing, and maintaining streets, sidewalks , water supply networks , sewers, street lighting , municipal solid waste management and disposal, storage depots for various bulk materials used for maintenance and public works (salt, sand, etc.), public parks and cycling infrastructure . In the case of underground utility networks, it may also include

2997-528: Is converted into a graphical representation of the Earth's surface in the form of a map. This information is then used by civil engineers, contractors and realtors to design from, build on, and trade, respectively. Elements of a structure must be sized and positioned in relation to each other and to site boundaries and adjacent structures. Although surveying is a distinct profession with separate qualifications and licensing arrangements, civil engineers are trained in

3108-433: Is defined to distinguish non-military engineering from military engineering. Civil engineering can take place in the public sector from municipal public works departments through to federal government agencies, and in the private sector from locally based firms to Fortune Global 500 companies. Civil engineering is the application of physical and scientific principles for solving the problems of society, and its history

3219-786: Is generally performed by specialized technicians. Unlike land surveyors, the resulting plan does not have legal status. Construction surveyors perform the following tasks: Transportation engineering is concerned with moving people and goods efficiently, safely, and in a manner conducive to a vibrant community. This involves specifying, designing, constructing, and maintaining transportation infrastructure which includes streets, canals, highways, rail systems , airports, ports, and mass transit . It includes areas such as transportation design, transportation planning , traffic engineering , some aspects of urban engineering , queueing theory , pavement engineering , Intelligent Transportation System (ITS), and infrastructure management. Municipal engineering

3330-480: Is intricately linked to advances in the understanding of physics and mathematics throughout history. Because civil engineering is a broad profession, including several specialized sub-disciplines, its history is linked to knowledge of structures, materials science, geography, geology , soils , hydrology , environmental science , mechanics , project management , and other fields. Throughout ancient and medieval history most architectural design and construction

3441-501: Is limited to the state of Queensland . Almost all certifying bodies maintain a code of ethics which all members must abide by. Engineers must obey contract law in their contractual relationships with other parties. In cases where an engineer's work fails, they may be subject to the law of tort of negligence , and in extreme cases, criminal charges. An engineer's work must also comply with numerous other rules and regulations such as building codes and environmental law . There are

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3552-419: 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

3663-456: 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

3774-591: 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 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

3885-484: Is the investigation of materials, products , structures or components that fail or do not operate or function as intended, causing personal injury or damage to property. The consequences of failure are dealt with by the law of product liability. The field also deals with retracing processes and procedures leading to accidents in operation of vehicles or machinery. The subject is applied most commonly in civil law cases, although it may be of use in criminal law cases. Generally

3996-477: 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

4107-403: 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

4218-465: Is the process by which a surveyor measures certain dimensions that occur on or near the surface of the Earth. Surveying equipment such as levels and theodolites are used for accurate measurement of angular deviation, horizontal, vertical and slope distances. With computerization, electronic distance measurement (EDM), total stations, GPS surveying and laser scanning have to a large extent supplanted traditional instruments. Data collected by survey measurement

4329-527: Is the work of Archimedes in the 3rd century BC, including Archimedes' principle , which underpins our understanding of buoyancy , and practical solutions such as Archimedes' screw . Brahmagupta , an Indian mathematician, used arithmetic in the 7th century AD, based on Hindu-Arabic numerals, for excavation (volume) computations. Engineering has been an aspect of life since the beginnings of human existence. The earliest practice of civil engineering may have commenced between 4000 and 2000 BC in ancient Egypt ,

4440-703: Is three to five years, and the completed degree is designated as a bachelor of technology , or a bachelor of engineering . The curriculum generally includes classes in physics, mathematics, project management , design and specific topics in civil engineering. After taking basic courses in most sub-disciplines of civil engineering, they move on to specialize in one or more sub-disciplines at advanced levels. While an undergraduate degree (BEng/BSc) normally provides successful students with industry-accredited qualifications, some academic institutions offer post-graduate degrees (MEng/MSc), which allow students to further specialize in their particular area of interest. In most countries,

4551-605: Is to help integrate the entire civil engineering project life cycle from conception, through planning, designing, making, operating to decommissioning. Prussian Academy of Sciences The Royal Prussian Academy of Sciences ( German : Königlich-Preußische Akademie der Wissenschaften ) was an academy established in Berlin , Germany on 11 July 1700, four years after the Prussian Academy of Arts , or "Arts Academy," to which "Berlin Academy" may also refer. In

Meander - Misplaced Pages Continue

4662-430: 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

4773-713: The Eddystone Lighthouse . In 1771 Smeaton and some of his colleagues formed the Smeatonian Society of Civil Engineers, a group of leaders of the profession who met informally over dinner. Though there was evidence of some technical meetings, it was little more than a social society. In 1818 the Institution of Civil Engineers was founded in London, and in 1820 the eminent engineer Thomas Telford became its first president. The institution received

4884-526: The Indus Valley civilization , and Mesopotamia (ancient Iraq) when humans started to abandon a nomadic existence, creating a need for the construction of shelter. During this time, transportation became increasingly important leading to the development of the wheel and sailing . Until modern times there was no clear distinction between civil engineering and architecture, and the term engineer and architect were mainly geographical variations referring to

4995-478: 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

5106-956: The Parthenon by Iktinos in Ancient Greece (447–438 BC), the Appian Way by Roman engineers ( c.  312 BC ), the Great Wall of China by General Meng T'ien under orders from Ch'in Emperor Shih Huang Ti ( c.  220 BC ) and the stupas constructed in ancient Sri Lanka like the Jetavanaramaya and the extensive irrigation works in Anuradhapura . The Romans developed civil structures throughout their empire, including especially aqueducts , insulae , harbors, bridges, dams and roads. In

5217-448: 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

5328-428: The design , construction , and maintenance of the physical and naturally built environment , including public works such as roads, bridges, canals, dams, airports, sewage systems , pipelines, structural components of buildings, and railways. Civil engineering is traditionally broken into a number of sub-disciplines. It is considered the second-oldest engineering discipline after military engineering , and it

5439-471: The 18th century, the term civil engineering was coined to incorporate all things civilian as opposed to military engineering. In 1747, the first institution for the teaching of civil engineering, the École Nationale des Ponts et Chaussées , was established in France; and more examples followed in other European countries, like Spain . The first self-proclaimed civil engineer was John Smeaton , who constructed

5550-416: The 18th century, when French was the language of science and culture, it was a French -language institution. Prince-elector Frederick III of Brandenburg , Germany founded the Academy under the name of Kurfürstlich Brandenburgische Societät der Wissenschaften ("Electoral Brandenburg Society of Sciences") upon the advice of Gottfried Wilhelm Leibniz , who was appointed president. Unlike other Academies,

5661-508: The Academy under the name of Deutsche Akademie der Wissenschaften zu Berlin (English: German Academy of Sciences at Berlin ) on 1 July 1946. In 1972, it was renamed Akademie der Wissenschaften der DDR or AdW (English: Academy of Sciences of the GDR ). At its height, the AdW had 400 researchers and 24,000 employees in locations across East Germany . Following German Reunification , the Academy

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5772-654: The Academy. In 1744, the Nouvelle Société Littéraire and the Society of Sciences were merged into the Königliche Akademie der Wissenschaften ("Royal Academy of Sciences"). An obligation from the new statute were public calls for ideas on unsolved scientific questions with a monetary reward for solutions. The Academy acquired its own research facilities in the 18th century, including an observatory in 1709; an anatomical theater in 1717;

5883-617: The Class of Civil Engineering and Mining was founded at King's College London in 1838, mainly as a response to the growth of the railway system and the need for more qualified engineers, the private College for Civil Engineers in Putney was established in 1839, and the UK's first Chair of Engineering was established at the University of Glasgow in 1840. Civil engineers typically possess an academic degree in civil engineering. The length of study

5994-593: The Prussian Academy was not directly funded out of the state treasury. Frederick granted it the monopoly on producing and selling calendars in Brandenburg, a suggestion from Leibniz. As Frederick was crowned " King in Prussia " in 1701, creating the Kingdom of Prussia , the Academy was renamed Königlich Preußische Sozietät der Wissenschaften ("Royal Prussian Society of Sciences"). While other Academies focused on

6105-633: The United States and Canada, "only a licensed professional engineer may prepare, sign and seal, and submit engineering plans and drawings to a public authority for approval, or seal engineering work for public and private clients." This requirement is enforced under provincial law such as the Engineers Act in Quebec . No such legislation has been enacted in other countries including the United Kingdom. In Australia, state licensing of engineers

6216-604: The United States was awarded by Rensselaer Polytechnic Institute in 1835. The first such degree to be awarded to a woman was granted by Cornell University to Nora Stanton Blatch in 1905. In the UK during the early 19th century, the division between civil engineering and military engineering (served by the Royal Military Academy, Woolwich ), coupled with the demands of the Industrial Revolution, spawned new engineering education initiatives:

6327-400: The academy was in a crisis for two decades at mid-century, due to scandals and internal rivalries such as the debates between Newtonianism and Leibnizian views, and the personality conflicts between the philosopher Voltaire and the mathematician Maupertuis . At a higher level, Maupertuis, the director from 1746 to 1759 and a monarchist , argued that the action of individuals was shaped by

6438-411: 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.,

6549-564: The basics of surveying and mapping, as well as geographic information systems . Surveyors also lay out the routes of railways, tramway tracks , highways, roads, pipelines and streets as well as position other infrastructure, such as harbors , before construction. In the United States, Canada, the United Kingdom and most Commonwealth countries land surveying is considered to be a separate and distinct profession. Land surveyors are not considered to be engineers, and have their own professional associations and licensing requirements. The services of

6660-551: 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

6771-404: 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 the inside to

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6882-557: 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

6993-552: The character of the institution that contained them, and they worked for the glory of the state. By contrast, d'Alembert took a republican rather than monarchical approach and emphasized the international Republic of Letters as the vehicle for scientific advance. By 1789, however, the academy had gained an international repute while making major contributions to German culture and thought. Frederick invited Joseph-Louis Lagrange to succeed Leonhard Euler as director; both were world-class mathematicians. Other intellectuals attracted to

7104-451: The civil portion (conduits and access chambers) of the local distribution networks of electrical and telecommunications services. It can also include the optimization of waste collection and bus service networks. Some of these disciplines overlap with other civil engineering specialties, however municipal engineering focuses on the coordination of these infrastructure networks and services, as they are often built simultaneously, and managed by

7215-499: The construction of ports, harbours, moles, breakwaters and lighthouses, and in the art of navigation by artificial power for the purposes of commerce, and in the construction and application of machinery, and in the drainage of cities and towns. The first private college to teach civil engineering in the United States was Norwich University , founded in 1819 by Captain Alden Partridge. The first degree in civil engineering in

7326-407: 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 the boundary layer. Therefore, within

7437-552: The corresponding committee's members. University departments emanated from some of these businesses after 1945. On 25 November 1915 Albert Einstein presented his field equations of general relativity to the Academy. Under the rule of Nazi Germany from 1933 to 1945, the Academy was subject to the Gleichschaltung , a "Nazification" process that was established to take totalitarian control over various aspects of society. However, compared with other institutions, such as

7548-406: 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

7659-404: 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

7770-529: The field of soil science , materials science, mechanics , and hydraulics is applied to safely and economically design foundations , retaining walls , and other structures. Environmental efforts to protect groundwater and safely maintain landfills have spawned a new area of research called geo-environmental engineering. Identification of soil properties presents challenges to geotechnical engineers. Boundary conditions are often well defined in other branches of civil engineering, but unlike steel or concrete,

7881-445: The flow and conveyance of fluids, principally water. This area of civil engineering is intimately related to the design of pipelines , water supply network , drainage facilities (including bridges, dams, channels , culverts , levees , storm sewers ), and canals. Hydraulic engineers design these facilities using the concepts of fluid pressure , fluid statics , fluid dynamics , and hydraulics, among others. Civil engineering systems

7992-535: The forefront of academic research. It is also an important part of forensic engineering and failure analysis . Site development , also known as site planning , is focused on the planning and development potential of a site as well as addressing possible impacts from permitting issues and environmental challenges . Structural engineering is concerned with the structural design and structural analysis of buildings, bridges, towers , flyovers (overpasses), tunnels, off shore structures like oil and gas fields in

8103-565: 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

8214-426: 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

8325-403: 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

8436-618: The function they are designed for (to be serviceable ). Due to the nature of some loading conditions, sub-disciplines within structural engineering have emerged, including wind engineering and earthquake engineering. Design considerations will include strength, stiffness, and stability of the structure when subjected to loads which may be static, such as furniture or self-weight, or dynamic, such as wind, seismic, crowd or vehicle loads, or transitory, such as temporary construction loads or impact. Other considerations include cost, constructibility, safety, aesthetics and sustainability . Surveying

8547-414: The hazardous waste management and environmental remediation work covered by environmental engineering. Public health engineering and environmental health engineering are other terms being used. Environmental engineering deals with treatment of chemical, biological, or thermal wastes, purification of water and air, and remediation of contaminated sites after waste disposal or accidental contamination. Among

8658-416: 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

8769-438: 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

8880-405: 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

8991-497: The material properties and behavior of soil are difficult to predict due to its variability and limitation on investigation . Furthermore, soil exhibits nonlinear ( stress -dependent) strength , stiffness, and dilatancy (volume change associated with application of shear stress ), making studying soil mechanics all the more difficult. Geotechnical engineers frequently work with professional geologists , Geological Engineering professionals and soil scientists. Materials science

9102-420: 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,

9213-416: 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

9324-503: 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

9435-415: 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 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,

9546-401: 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

9657-436: 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,

9768-528: 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

9879-411: 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

9990-706: The philosopher's kingdom were Francesco Algarotti , Jean-Baptiste de Boyer , and Julien Offray de La Mettrie . Immanuel Kant published religious writings in Berlin which would have been censored elsewhere in Europe. Beginning in 1815, research businesses led by Academy committees (such as the Greek-Roman Archeology Committee or the Oriental Committee) were founded at the Academy. They employed mostly scientists to work alongside

10101-474: 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

10212-454: The prediction and management of both the quality and the quantity of water in both underground ( aquifers ) and above ground (lakes, rivers, and streams) resources. Water resource engineers analyze and model very small to very large areas of the earth to predict the amount and content of water as it flows into, through, or out of a facility. However, the actual design of the facility may be left to other engineers. Hydraulic engineering concerns

10323-405: The purpose of a Forensic engineering investigation is to locate cause or causes of failure with a view to improve performance or life of a component, or to assist a court in determining the facts of an accident. It can also involve investigation of intellectual property claims, especially patents . Geotechnical engineering studies rock and soil supporting civil engineering systems. Knowledge from

10434-622: 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

10545-558: The same municipal authority. Municipal engineers may also design the site civil works for large buildings, industrial plants or campuses (i.e. access roads, parking lots, potable water supply, treatment or pretreatment of waste water, site drainage, etc.) Water resources engineering is concerned with the collection and management of water (as a natural resource ). As a discipline, it therefore combines elements of hydrology, environmental science, meteorology , conservation , and resource management . This area of civil engineering relates to

10656-512: The same occupation, and often used interchangeably. The constructions of pyramids in Egypt ( c.  2700 –2500 BC) constitute some of the first instances of large structure constructions in history. Other ancient historic civil engineering constructions include the Qanat water management system in modern-day Iran (the oldest is older than 3000 years and longer than 71 kilometres (44 mi) ),

10767-416: 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

10878-534: The sea, aerostructure and other structures. This involves identifying the loads which act upon a structure and the forces and stresses which arise within that structure due to those loads, and then designing the structure to successfully support and resist those loads. The loads can be self weight of the structures, other dead load, live loads, moving (wheel) load, wind load, earthquake load, load from temperature change etc. The structural engineer must design structures to be safe for their users and to successfully fulfill

10989-417: 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

11100-503: 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

11211-445: 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

11322-421: 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 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

11433-411: 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,

11544-419: 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,

11655-401: 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

11766-416: 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

11877-468: The throne in 1740, the academy was overshadowed by similar bodies in London and Paris . Frederick made French the official language and speculative philosophy the most important topic of study. The membership was strong in mathematics and philosophy, and included notable philosophers such as Immanuel Kant , Jean-Baptiste le Rond d'Alembert , Pierre-Louis de Maupertuis , and Etienne de Condillac . However,

11988-433: The topics covered by environmental engineering are pollutant transport, water purification , waste water treatment , air pollution, solid waste treatment , recycling , and hazardous waste management . Environmental engineers administer pollution reduction, green engineering , and industrial ecology . Environmental engineers also compile information on environmental consequences of proposed actions. Forensic engineering

12099-403: 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

12210-753: The universities where Jewish employees and members were expelled starting in 1933, Jewish Academy members were not expelled until 1938, following a direct request by the Ministry of Education. The new Academy statute went into effect on 8 June 1939, reorganizing the Academy according to the Nazi leadership principle (the Führerprinzip ). Following World War II , the Soviet Military Administration in Germany , or SMAD , reorganized

12321-416: Was carried out by artisans , such as stonemasons and carpenters , rising to the role of master builder . Knowledge was retained in guilds and seldom supplanted by advances. Structures, roads, and infrastructure that existed were repetitive, and increases in scale were incremental. One of the earliest examples of a scientific approach to physical and mathematical problems applicable to civil engineering

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