A trench is a type of excavation or depression in the ground that is generally deeper than it is wide, and narrow compared with its length. In geology, trenches are created as a result of erosion by rivers or by geological movement of tectonic plates, in the civil engineering field, trenches are often created to install underground infrastructure or utilities, or to access these installations. Trenches have often been dug for defensive purposes. In archaeology, the method is used for searching and excavating ancient ruins or to dig into strata of sedimented material. Some trenches are created as a result of erosion by running water or by glaciers, such as rift valleys or more commonly oceanic trenches, are created by geological movement of tectonic plates. Some oceanic trenches include the Mariana Trench and the Aleutian Trench, the former geoform is relatively deep and narrow, and is formed by plate subduction when plates converge. In the civil engineering field of construction or maintenance of infrastructure and they are used to place underground easily damaged and obstructive infrastructure or utilities. A similar use for higher bulk would be in pipeline transport and they may be created to search for pipes and other infrastructure that is known to be underground in the general area, but whose exact location has been lost.
Finally, trenches may be created as the first step of creating a foundation wall, Trench shoring is often used in trenchworks to protect workers and stabilise embankments. An alternative to digging trenches is to create a utility tunnel, the advantages of utility tunnels are the reduction of maintenance manholes, one-time relocation, and less excavation and repair, compared with separate cable ducts for each service. When they are well mapped, they allow access to all utilities without having to dig access trenches or resort to confused. One of the greatest advantages is public safety, for a comparison of utility tunnels vs. direct burial, see the article referred to above. In some cases, a trench is dug and deliberately preserved. This is typically done to install depressed motorways, open railway cuttings, trenches have often been dug for defensive purposes. In the pre-firearm eras, they were mainly a type of hindrance to an attacker of a fortified location, an early example of this can be seen in the Battle of the Trench, one of the early Battles of the Islamic Prophet Muhammad.
With the advent of firearms, trenches were used to shelter troops. The advantage of this method is that it only a small part of the site. However, this has the disadvantage of only revealing small slices of the whole volume
Arable land is, according to one definition, land capable of being ploughed and used to grow crops. In Britain, it was contrasted with pasturable lands such as heaths which could be used for sheep-rearing. A quite different kind of definition is used by various agencies concerned with agriculture, the abandoned land resulting from shifting cultivation is not included in this category. Data for ‘Arable land’ are not meant to indicate the amount of land that is potentially cultivable, a briefer definition appearing in the Eurostat glossary similarly refers to actual, rather than potential use, land worked regularly, generally under a system of crop rotation. According to Food and Agriculture Organization of the United Nations the worlds Arable land amounted to 1,407 M ha, out of a total 4,924 M ha land used for agriculture, as for year 2013. Agricultural land that is not arable according to the FAO definition above includes, Permanent crop - land that produces crops from woody vegetation, other non-arable land includes land unsuitable for any agricultural use.
Although such limitations may preclude cultivation, and some will in some cases preclude any agricultural use, for example, US NRCS statistics indicate that about 59 percent of US non-federal pasture and unforested rangeland is unsuitable for cultivation, yet such land has value for grazing of livestock. Similar examples can be found in many rangeland areas elsewhere, land incapable of being cultivated for production of crops can sometimes be converted to arable land. New arable land makes more food, and can reduce starvation and this outcome makes a country more self-sufficient and politically independent, because food importation is reduced. This process is extremely expensive. An alternative is the Seawater Greenhouse which desalinates water through evaporation and condensation using solar energy as the energy input. This technology is optimized to grow crops on land close to the sea. The people covered the islands with a layer of seaweed. Israel, The construction of desalination plants along Israels coast allowed agriculture in areas that were formerly desert.
The desalination plants, which remove the salt from water, have created a new source of water for farming, drinking. Slash and burn agriculture uses nutrients in wood ash, but these expire within a few years, terra preta, fertile tropical soils created by adding charcoal. Some examples of fertile land being turned into infertile land are. Rainforest deforestation, The fertile tropical forests are converted into infertile desert land, for example, Madagascars central highland plateau has become virtually totally barren, as a result of slash-and-burn deforestation, an element of shifting cultivation practiced by many natives
Sediment transport is the movement of solid particles, typically due to a combination of gravity acting on the sediment, and/or the movement of the fluid in which the sediment is entrained. Sediment transport due to fluid motion occurs in rivers, lakes, Transport is caused by glaciers as they flow, and on terrestrial surfaces under the influence of wind. Sediment transport due only to gravity can occur on sloping surfaces in general, including hillslopes, cliffs, sediment transport is important in the fields of sedimentary geology, civil engineering and environmental engineering. Aeolian or eolian is the term for sediment transport by wind and this process results in the formation of ripples and sand dunes. Typically, the size of the sediment is fine sand and smaller, because air is a fluid with low density and viscosity. Bedforms are generated by aeolian sediment transport in the terrestrial near-surface environment and dunes form as a natural self-organizing response to sediment transport.
Aeolian sediment transport is common on beaches and in the regions of the world, because it is in these environments that vegetation does not prevent the presence. Wind-blown very fine-grained dust is capable of entering the upper atmosphere, dust from the Sahara deposits on the Canary Islands and islands in the Caribbean, and dust from the Gobi desert has deposited on the western United States. This sediment is important to the budget and ecology of several islands. Deposits of fine-grained wind-blown glacial sediment are called loess, in geology, physical geography, and sediment transport, fluvial processes relate to flowing water in natural systems. This encompasses rivers, periglacial flows, flash floods, sediment moved by water can be larger than sediment moved by air because water has both a higher density and viscosity. In typical rivers the largest carried sediment is of sand and gravel size, coastal sediment transport takes place in near-shore environments due to the motions of waves and currents.
At the mouths of rivers, coastal sediment and fluvial sediment transport processes mesh to create river deltas, coastal sediment transport results in the formation of characteristic coastal landforms such as beaches, barrier islands, and capes. As glaciers move over their beds, they entrain and move material of all sizes, glaciers can carry the largest sediment, and areas of glacial deposition often contain a large number of glacial erratics, many of which are several metres in diameter. Glaciers pulverize rock into glacial flour, which is so fine that it is carried away by winds to create loess deposits thousands of kilometres afield. Sediment entrained in glaciers often moves approximately along the glacial flowlines, in hillslope sediment transport, a variety of processes move regolith downslope. For this reason, the tops of hills generally have a parabolic concave-up profile, as hillslopes steepen, they become more prone to episodic landslides and other mass wasting events. Large masses of material are moved in debris flows, hyperconcentrated mixtures of mud, clasts that range up to boulder-size, debris flows move as granular flows down steep mountain valleys and washes
Water is a transparent and nearly colorless chemical substance that is the main constituent of Earths streams and oceans, and the fluids of most living organisms. Its chemical formula is H2O, meaning that its molecule contains one oxygen, Water strictly refers to the liquid state of that substance, that prevails at standard ambient temperature and pressure, but it often refers to its solid state or its gaseous state. It occurs in nature as snow, ice packs and icebergs, fog, aquifers, Water covers 71% of the Earths surface. It is vital for all forms of life. Only 2. 5% of this water is freshwater, and 98. 8% of that water is in ice and groundwater. Less than 0. 3% of all freshwater is in rivers and the atmosphere, a greater quantity of water is found in the earths interior. Water on Earth moves continually through the cycle of evaporation and transpiration, precipitation. Evaporation and transpiration contribute to the precipitation over land, large amounts of water are chemically combined or adsorbed in hydrated minerals.
Safe drinking water is essential to humans and other even though it provides no calories or organic nutrients. There is a correlation between access to safe water and gross domestic product per capita. However, some observers have estimated that by 2025 more than half of the population will be facing water-based vulnerability. A report, issued in November 2009, suggests that by 2030, in developing regions of the world. Water plays an important role in the world economy, approximately 70% of the freshwater used by humans goes to agriculture. Fishing in salt and fresh water bodies is a source of food for many parts of the world. Much of long-distance trade of commodities and manufactured products is transported by boats through seas, lakes, large quantities of water and steam are used for cooling and heating, in industry and homes. Water is an excellent solvent for a variety of chemical substances, as such it is widely used in industrial processes. Water is central to many sports and other forms of entertainment, such as swimming, pleasure boating, boat racing, sport fishing, Water is a liquid at the temperatures and pressures that are most adequate for life.
Specifically, at atmospheric pressure of 1 bar, water is a liquid between the temperatures of 273.15 K and 373.15 K
This dimensionless quantity can be rephrased as the actual path length divided by the shortest path length of a curve. The value ranges from 1 to infinity or for an actual path. The curve must be continuous between the two ends, the sinuosity value is really significant when the line is continuously differentiable. The distance between both ends can be evaluated by a plurality of segments according to a line passing through the successive inflection points. The calculation of the sinuosity is valid in a 3-dimensional space, nevertheless, it is possible to see a very strong sinuosity in the succession of few river bends, or of laces on some mountain roads. The sinuosity S of,2 inverted continuous semicircles located in the plane is S = π2 ≈1.5708. It is independent of the radius, a sine function. The sinuosity index can be explained, then, as the deviations from a path defined by the direction of maximum downslope. For this reason, bedrock streams that flow directly downslope have a sinuosity index of 1, and meandering streams have a sinuosity index that is greater than 1.
For rivers, the classes of sinuosity, SI, are, SI <1.05, almost straight 1.05 ≤ SI <1.25, winding 1.25 ≤ SI <1.50
Drainage system (agriculture)
An agricultural drainage system is a system by which water is drained on or in the soil to enhance agricultural production of crops. It may involve any combination of control, erosion control. While there are more than two types of drainage systems employed in agriculture, there are two types, surface drainage and sub-surface drainage. Figure 1 classifies the types of drainage systems. It shows the field and the main systems, in some instances one makes an additional distinction between collector and main drainage systems. Field drainage systems are differentiated in surface and subsurface drainage systems. Sometimes, a form of drainage is required whereby the drainage system is allowed to function only on certain occasions. If allowed to function continuously, excessive quantities of water would be lost, such a system is therefore called a checked, or controlled, drainage system. In agricultural literature, this is called a relief drainage system. The regular surface drainage systems, which start functioning as soon as there is an excess of rainfall or irrigation applied, the bedded and graded systems may have ridges and furrows.
The checked surface drainage systems consist of check gates placed in the surrounding flat basins. These fields are usually submerged and only need to be drained on certain occasions, checked surface drainage systems are found in terraced lands used for rice. It is therefore difficult to develop sound agricultural criteria for the surface field drainage systems. Most of the criteria for these systems concern the efficiency of the techniques of land leveling and earthmoving. Similarly, agricultural criteria for checked surface drainage systems are not very well known, like the surface field drainage systems, the subsurface field drainage systems can be differentiated in regular systems and checked systems. They can save much irrigation water, a checked drainage system reduces the discharge through the main drainage system, thereby reducing construction costs. When the discharge takes place by pumping, the drainage can be checked simply by not operating the pumps or by reducing the pumping time.
In northwestern India, this practice has increased the efficiency and reduced the quantity of irrigation water needed
A stream is a body of water with a current, confined within a bed and banks. Streams are important as conduits in the cycle, instruments in groundwater recharge. The biological habitat in the vicinity of a stream is called a riparian zone. Given the status of the ongoing Holocene extinction, streams play an important corridor role in connecting fragmented habitats, the study of streams and waterways in general is known as surface hydrology and is a core element of environmental geography. Brook A stream smaller than a creek, especially one that is fed by a spring or seep and it is usually small and easily forded. A brook is characterised by its shallowness and its bed being composed primarily of rocks, creek In North America and New Zealand, a small to medium-sized natural stream. Sometimes navigable by motor craft and may be intermittent, in parts of Maryland, New England, the UK and India, a tidal inlet, typically in a salt marsh or mangrove swamp, or between enclosed and drained former salt marshes or swamps.
In these cases, the stream is the stream, the course of the seawater through the creek channel at low. River A large natural stream, which may be a waterway, runnel the linear channel between the parallel ridges or bars on a shoreline beach or river floodplain, or between a bar and the shore. Tributary A contributory stream, or a stream which does not reach the sea, sometimes called a branch or fork. There are a number of names for a stream. Allt is used in Highland Scotland, beck is used in Yorkshire, Dumfriesshire, Cumbria and Lincolnshire. Bourne or winterbourne is used in the chalk downland of southern England, brook is used in the Midlands and Cheshire. Burn is used in Scotland and North East England, gill or ghyll is seen in the north of England and other areas influenced by Old Norse. Rivulet is an term encountered in Victorian era publications, stream is used in Southern England. Syke is used in lowland Scotland and Cumbria for a seasonal stream, branch is used to name streams in Maryland and Virginia.
Falls is used to name streams in Maryland, for streams/rivers which have waterfalls on them, little Gunpowder Falls and The Jones Falls are actually rivers named in this manner, unique to Maryland. Kill in New York, Pennsylvania and New Jersey comes from a Dutch language word meaning riverbed or water channel, run in Ohio, Michigan, New Jersey, Virginia, or West Virginia can be the name of a stream
Canals and navigations are human-made channels for water conveyance, or to service water transport vehicles. In the vernacular, both are referred to as canals, and in most cases, the works will have a series of dams. These areas are referred to as water levels, often just called levels. In contrast, a canal cuts across a drainage divide atop a ridge, many canals have been built at elevations towering over valleys and others water ways crossing far below. Cities need a lot of water and many canals with sources of water at a higher level can deliver water to a destination where there is a lack of water. The Roman Empires Aqueducts were such water supply canals, a navigation is a series of channels that run roughly parallel to the valley and stream bed of an unimproved river. A navigation always shares the drainage basin of the river, a vessel uses the calm parts of the river itself as well as improvements, traversing the same changes in height. A true canal is a channel that cuts across a drainage divide, most commercially important canals of the first half of the 19th century were a little of each, using rivers in long stretches, and divide crossing canals in others.
This is true for many canals still in use, there are two broad types of canal, Waterways and navigations used for carrying vessels transporting goods and people. These can be subdivided into two kinds, Those connecting existing lakes, other canals or seas and oceans and those connected in a city network, such as the Canal Grande and others of Venice Italy, the gracht of Amsterdam, and the waterways of Bangkok. Aqueducts, water canals that are used for the conveyance and delivery of potable water for human consumption, municipal uses, hydro power canals. Historically canals were of importance to commerce and the development, growth. In 1855 the Lehigh Canal carried over 1.2 million tons of burning anthracite coal, by the 1930s the company which built. By the early 1880s, canals which had little ability to compete with rail transport, were off the map. In the next couple of decades, coal was diminished as the heating fuel of choice by oil. Later, after World War I when motor-trucks came into their own, Canals are built in one of three ways, or a combination of the three, depending on available water and available path, Human made streams A canal can be created where no stream presently exists.
Either the body of the canal is dug or the sides of the canal are created by making dykes or levees by piling dirt, the water for the canal must be provided from an external source, like streams or reservoirs. Where the new waterway must change elevation engineering works like locks, lifts or elevators are constructed to raise, examples include canals that connect valleys over a higher body of land, like Canal du Midi, Canal de Briare and the Panama Canal
Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of chemical substances or energy, such as noise, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. Pollution is often classed as point source or nonpoint source pollution, Air pollution has always accompanied civilizations. Pollution started from prehistoric times when man created the first fires, metal forging appears to be a key turning point in the creation of significant air pollution levels outside the home. The burning of coal and wood, and the presence of horses in concentrated areas made the cities the cesspools of pollution. The Industrial Revolution brought an infusion of untreated chemicals and wastes into local streams that served as the water supply, king Edward I of England banned the burning of sea-coal by proclamation in London in 1272, after its smoke became a problem. But the fuel was so common in England that this earliest of names for it was acquired because it could be carted away from some shores by the wheelbarrow and it was the industrial revolution that gave birth to environmental pollution as we know it today.
London recorded one of the extreme cases of water quality problems with the Great Stink on the Thames of 1858. Pollution issues escalated as population growth far exceeded view ability of neighborhoods to handle their waste problem, reformers began to demand sewer systems, and clean water. In 1870, the conditions in Berlin were among the worst in Europe. There were no toilets in the streets or squares. Visitors, especially women, often became desperate when nature called, in the public buildings the sanitary facilities were unbelievably primitive. As a metropolis, Berlin did not emerge from a state of barbarism into civilization until after 1870. Chicago and Cincinnati were the first two American cities to enact laws ensuring cleaner air in 1881, as historian Martin Melosi notes, The generation that first saw automobiles replacing the horses saw cars as miracles of cleanliness. By the 1940s, automobile-caused smog was an issue in Los Angeles. Other cities followed around the country early in the 20th century.
Extreme smog events were experienced by the cities of Los Angeles and Donora, Pennsylvania in the late 1940s, Air pollution would continue to be a problem in England, especially during the industrial revolution, and extending into the recent past with the Great Smog of 1952. Awareness of atmospheric pollution spread widely after World War II, with fears triggered by reports of fallout from atomic warfare. Then a non-nuclear event, The Great Smog of 1952 in London and this prompted some of the first major modern environmental legislation, The Clean Air Act of 1956
Cycling, called bicycling or biking, is the use of bicycles for transport, exercise or sport. Persons engaged in cycling are referred to as cyclists, bikers, or less commonly, apart from two-wheeled bicycles, cycling includes the riding of unicycles, quadracycles and similar human-powered vehicles. Bicycles were introduced in the 19th century and now approximately one billion worldwide. They are the means of transportation in many parts of the world. Cycling is widely regarded as an effective and efficient mode of transportation optimal for short to moderate distances. Cycling offers a reduced consumption of fuels, less air or noise pollution. These lead to financial cost to the user as well as to society at large. By fitting bicycle racks on the front of buses, transit agencies can significantly increase the areas they can serve, in many countries, the most commonly used vehicle for road transport is a utility bicycle. These have frames with relaxed geometry, protecting the rider from shocks of the road, utility bicycles tend to be equipped with accessories such as mudguards, pannier racks and lights, which extends their usefulness on a daily basis.
As the bicycle is so effective as a means of various companies have developed methods of carrying anything from the weekly shop to children on bicycles. Certain countries rely heavily on bicycles and their culture has developed around the bicycle as a form of transport. In Europe and the Netherlands have the most bicycles per capita, road bikes tend to have a more upright shape and a shorter wheelbase, which make the bike more mobile but harder to ride slowly. The design, coupled with low or dropped handlebars, requires the rider to bend forward more, making use of stronger muscles, the price of a new bicycle can range from US$50 to more than US$20,000, depending on quality and weight. However, UCI regulations stipulate a legal race bike cannot weigh less than 6.8 kg, being measured for a bike and taking it for a test ride are recommended before buying. The drivetrain components of the bike should be considered, a middle grade dérailleur is sufficient for a beginner, although many utility bikes are equipped with hub gears.
If the rider plans a significant amount of hillclimbing a triple-chainrings crankset gear system may be preferred, the relatively lighter and less expensive double chainring may be better. Much simpler fixed wheel bikes are available, many road bikes, along with mountain bikes, include clipless pedals to which special shoes attach, via a cleat, enabling the rider to pull on the pedals as well as push. For basic maintenance and repairs cyclists can carry a pump, a repair kit, a spare inner tube, and tire levers
Colorado is a state in the United States encompassing most of the Southern Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains. Colorado is part of the Western United States, the Southwestern United States, Colorado is the 8th most extensive and the 21st most populous of the 50 United States. The United States Census Bureau estimates that the population of Colorado was 5,540,545 on July 1,2016, the state was named for the Colorado River, which Spanish travelers named the Río Colorado for the ruddy silt the river carried from the mountains. The Territory of Colorado was organized on February 28,1861, Colorado is nicknamed the Centennial State because it became a state in the same year as the centennial of the United States Declaration of Independence. Colorado is noted for its landscape of mountains, high plains, canyons, rivers. Denver is the capital and the most populous city of Colorado, residents of the state are properly known as Coloradans, although the term Coloradoan has been used archaically and lives on in the title of Fort Collins newspaper, the Coloradoan.
Colorado and Utah are the states which have boundaries defined solely by lines of latitude and longitude. The summit of Mount Elbert at 14,440 feet elevation in Lake County is the highest point in Colorado, Colorado is the only U. S. state that lies entirely above 1,000 meters elevation. The point where the Arikaree River flows out of Yuma County and this point, which holds the distinction of being the highest low elevation point of any state, is higher than the high elevation points of 18 states and the District of Columbia. A little less than one half of the area of Colorado is flat, East of the Rocky Mountains are the Colorado Eastern Plains of the High Plains, the section of the Great Plains within Nebraska at elevations ranging from roughly 3,350 to 7,500 feet. The Colorado plains were mostly prairies, but they have many patches of forests, buttes. Eastern Colorado is presently covered in farmland and rangeland, along with small farming villages. Precipitation is fair, averaging from 15 to 25 inches annually, wheat, hay and oats are all typical crops, and most of the villages and towns in this region boast both a water tower and a grain elevator.
Irrigation water is available from the South Platte, the Arkansas River, and a few other streams, heavy use of ground water from wells for irrigation has caused underground water reserves to decline. As well as agriculture, eastern Colorado hosts considerable livestock, such as cattle ranches. Roughly 70% of Colorados population resides along the edge of the Rocky Mountains in the Front Range Urban Corridor between Cheyenne and Pueblo, Colorado. This region is protected from prevailing storms that blow in from the Pacific Ocean region by the high Rockies in the middle of Colorado. The Front Range includes Denver, Fort Collins, Colorado Springs, Pueblo and other townships, on the other side of the Rockies, the significant population centers in Western Colorado are the cities of Grand Junction and Montrose
The Netherlands, informally known as Holland is the main constituent country of the Kingdom of the Netherlands. It is a densely populated country located in Western Europe with three territories in the Caribbean. The European part of the Netherlands borders Germany to the east, Belgium to the south, and the North Sea to the northwest, sharing borders with Belgium, the United Kingdom. The three largest cities in the Netherlands are Amsterdam and The Hague, Amsterdam is the countrys capital, while The Hague holds the Dutch seat of parliament and government. The port of Rotterdam is the worlds largest port outside East-Asia, the name Holland is used informally to refer to the whole of the country of the Netherlands. Netherlands literally means lower countries, influenced by its low land and flat geography, most of the areas below sea level are artificial. Since the late 16th century, large areas have been reclaimed from the sea and lakes, with a population density of 412 people per km2 –507 if water is excluded – the Netherlands is classified as a very densely populated country.
Only Bangladesh, South Korea, and Taiwan have both a population and higher population density. Nevertheless, the Netherlands is the worlds second-largest exporter of food and agricultural products and this is partly due to the fertility of the soil and the mild climate. In 2001, it became the worlds first country to legalise same-sex marriage, the Netherlands is a founding member of the EU, Eurozone, G-10, NATO, OECD and WTO, as well as being a part of the Schengen Area and the trilateral Benelux Union. The first four are situated in The Hague, as is the EUs criminal intelligence agency Europol and this has led to the city being dubbed the worlds legal capital. The country ranks second highest in the worlds 2016 Press Freedom Index, the Netherlands has a market-based mixed economy, ranking 17th of 177 countries according to the Index of Economic Freedom. It had the thirteenth-highest per capita income in the world in 2013 according to the International Monetary Fund, in 2013, the United Nations World Happiness Report ranked the Netherlands as the seventh-happiest country in the world, reflecting its high quality of life.
The Netherlands ranks joint second highest in the Inequality-adjusted Human Development Index, the region called Low Countries and the country of the Netherlands have the same toponymy. Place names with Neder, Nieder and Nedre and Bas or Inferior are in use in all over Europe. They are sometimes used in a relation to a higher ground that consecutively is indicated as Upper, Oben. In the case of the Low Countries / the Netherlands the geographical location of the region has been more or less downstream. The geographical location of the region, changed over time tremendously