|
Open Terrain
Open terrain, open country or open ground is terrain which is mostly flat and free of obstructions such as trees and buildings. Examples include farmland, grassland and specially cleared areas such as an airport. Such terrain is significant in military manoeuvre and tactics as the lack of obstacles makes movement easy and engagements are possible at long range. Such terrain is preferred to close terrain for offensive action as rapid movement makes decisive battles possible. Wind loading tends to be high in open country as there are few obstacles providing a windbreak. This affects the design of tall structures such electricity pylons and windmill A windmill is a structure that converts wind power into rotational energy using vanes called sails or blades, specifically to mill grain (gristmills), but the term is also extended to windpumps, wind turbines, and other applications, in some ...s. See also * Open Country References Physical geography Topography { ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terrain
Terrain or relief (also topographical relief) involves the vertical and horizontal dimensions of land surface. The term bathymetry is used to describe underwater relief, while hypsometry studies terrain relative to sea level. The Latin word (the root of ''terrain'') means "earth." In physical geography, terrain is the lay of the land. This is usually expressed in terms of the elevation, slope, and orientation of terrain features. Terrain affects surface water flow and distribution. Over a large area, it can affect weather and climate patterns. Importance The understanding of terrain is critical for many reasons: * The terrain of a region largely determines its suitability for human settlement: flatter alluvial plains tend to have better farming soils than steeper, rockier uplands. * In terms of environmental quality, agriculture, hydrology and other interdisciplinary sciences; understanding the terrain of an area assists the understanding of watershed boundaries, dr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Farmland
Agricultural land is typically land ''devoted to'' agriculture, the systematic and controlled use of other forms of lifeparticularly the rearing of livestock and production of cropsto produce food for humans. It is generally synonymous with both farmland or cropland, as well as pasture or rangeland. The United Nations Food and Agriculture Organization (FAO) and others following its definitions, however, also use ''agricultural land'' or as a term of art, where it means the collection of: * ''arable land'' (also known as ''cropland''): here redefined to refer to land producing crops requiring annual replanting or fallowland or pasture used for such crops within any five-year period * '' permanent cropland'': land producing crops which do not require annual replanting * ''permanent pastures'': natural or artificial grasslands and shrublands able to be used for grazing livestock This sense of "agricultural land" thus includes a great deal of land not devoted to agricultural u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grassland
A grassland is an area where the vegetation is dominated by grasses ( Poaceae). However, sedge ( Cyperaceae) and rush ( Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur naturally on all continents except Antarctica and are found in most ecoregions of the Earth. Furthermore, grasslands are one of the largest biomes on earth and dominate the landscape worldwide. There are different types of grasslands: natural grasslands, semi-natural grasslands, and agricultural grasslands. They cover 31–69% of the Earth's land area. Definitions Included among the variety of definitions for grasslands are: * "...any plant community, including harvested forages, in which grasses and/or legumes make up the dominant vegetation." * "...terrestrial ecosystems dominated by herbaceous and shrub vegetation, and maintained by fire, grazing, drought and/or freezing temperatures." (Pilot Assessment of Global Ecosystems, 2000) * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airport
An airport is an aerodrome with extended facilities, mostly for commercial air transport. Airports usually consists of a landing area, which comprises an aerially accessible open space including at least one operationally active surface such as a runway for a plane to take off and to land or a helipad, and often includes adjacent utility buildings such as control towers, hangars and terminals, to maintain and monitor aircraft. Larger airports may have airport aprons, taxiway bridges, air traffic control centres, passenger facilities such as restaurants and lounges, and emergency services. In some countries, the US in particular, airports also typically have one or more fixed-base operators, serving general aviation. Operating airports is extremely complicated, with a complex system of aircraft support services, passenger services, and aircraft control services contained within the operation. Thus airports can be major employers, as well as important hubs for t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strategy
Strategy (from Greek στρατηγία ''stratēgia'', "art of troop leader; office of general, command, generalship") is a general plan to achieve one or more long-term or overall goals under conditions of uncertainty. In the sense of the " art of the general", which included several subsets of skills including military tactics, siegecraft, logistics etc., the term came into use in the 6th century C.E. in Eastern Roman terminology, and was translated into Western vernacular languages only in the 18th century. From then until the 20th century, the word "strategy" came to denote "a comprehensive way to try to pursue political ends, including the threat or actual use of force, in a dialectic of wills" in a military conflict, in which both adversaries interact. Strategy is important because the resources available to achieve goals are usually limited. Strategy generally involves setting goals and priorities, determining actions to achieve the goals, and mobilizing resources to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military Tactics
Military tactics encompasses the art of organizing and employing fighting forces on or near the battlefield. They involve the application of four battlefield functions which are closely related – kinetic or firepower, Mobility (military), mobility, protection or security, and Shock tactics, shock action. Tactics are a separate function from command and control and logistics. In contemporary military science, tactics are the lowest of three levels of warfighting, the higher levels being the military strategy, strategic and Operational level of war, operational levels. Throughout history, there has been a shifting balance between the four tactical functions, generally based on the application of military technology, which has led to one or more of the tactical functions being dominant for a period of time, usually accompanied by the dominance of an associated Combat arms, fighting arm deployed on the battlefield, such as infantry, artillery, cavalry or tanks. Tactical functions Ki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Close Terrain
Close combat means a violent physical confrontation between two or more opponents at short range.''MCRP 3-02B: Close Combat'', Washington, D.C.: Department Of The Navy, Headquarters United States Marine Corps, 12 February 1999Matthews, Phil, CQB Services, retrieved 29 July 2011: At his Specialist Close Combat Course, combat instructor Capt. William E. Fairbairn defined close combat as "fighting an enemy hand to hand or within 20 yards range.” Armed and unarmed confrontations Among many types of fighting encompassed by the general term ''close combat'' are the modern terms ''hand-to-hand combat'' (HTH) and ''close-quarters combat'' (CQC). Close combat occurs when opposing military forces engage in restricted areas, an environment frequently encountered in urban warfare. Military small unit tactics traditionally regarded as forms of close combat include fighting with hand-held or hand-thrown weapons such as swords, knives, axes, or tools. In modern times, (since World War II), t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Loading
Wind engineering is a subset of mechanical engineering, structural engineering, meteorology, and applied physics that analyzes the effects of wind in the natural and the built environment and studies the possible damage, inconvenience or benefits which may result from wind. In the field of engineering it includes strong winds, which may cause discomfort, as well as extreme winds, such as in a tornado, hurricane or heavy storm, which may cause widespread destruction. In the fields of wind energy and air pollution it also includes low and moderate winds as these are relevant to electricity production and dispersion of contaminants. Wind engineering draws upon meteorology, fluid dynamics, mechanics, geographic information systems, and a number of specialist engineering disciplines, including aerodynamics and structural dynamics. The tools used include atmospheric models, atmospheric boundary layer wind tunnels, and computational fluid dynamics models. Wind engineering involves, among ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windbreak
A windbreak (shelterbelt) is a planting usually made up of one or more rows of trees or shrubs planted in such a manner as to provide shelter from the wind and to protect soil from erosion. They are commonly planted in hedgerows around the edges of fields on farms. If designed properly, windbreaks around a home can reduce the cost of heating and cooling and save energy. Windbreaks are also planted to help keep snow from drifting onto roadways or yards. Farmers sometimes use windbreaks to keep snow drifts on farm land that will provide water when the snow melts in the spring. Other benefits include contributing to a microclimate around crops (with slightly less drying and chilling at night), providing habitat for wildlife, and, in some regions, providing wood if the trees are harvested. Windbreaks and intercropping can be combined in a farming practice referred to as alleycropping, or being deployed along riparian buffer stripes. Fields are planted in rows of different crops surr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electricity Pylon
A transmission tower, also known as an electricity pylon or simply a pylon in British English and as a hydro tower in Canadian English, is a tall structure, usually a steel lattice tower, used to support an overhead power line. In electrical grids, they are generally used to carry high-voltage transmission lines that transport bulk electric power from generating stations to electrical substations; utility poles are used to support lower-voltage subtransmission and distribution lines that transport power from substations to electric customers. They come in a wide variety of shapes and sizes. Typical height ranges from , though the tallest are the towers of a span between the islands Jintang and Cezi in China's Zhejiang province. The longest span of any hydroelectric crossing ever built belongs to the powerline crossing of Ameralik fjord with a length of . In addition to steel, other materials may be used, including concrete and wood. There are four major categories o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windmill
A windmill is a structure that converts wind power into rotational energy using vanes called sails or blades, specifically to mill grain (gristmills), but the term is also extended to windpumps, wind turbines, and other applications, in some parts of the English speaking world. The term wind engine is sometimes used to describe such devices. Windmills were used throughout the high medieval and early modern periods; the horizontal or panemone windmill first appeared in Persia during the 9th century, and the vertical windmill first appeared in northwestern Europe in the 12th century. Regarded as an icon of Dutch culture, there are approximately 1,000 windmills in the Netherlands today. Forerunners Wind-powered machines may have been known earlier, but there is no clear evidence of windmills before the 9th century. Hero of Alexandria (Heron) in first-century Roman Egypt described what appears to be a wind-driven wheel to power a machine.Dietrich Lohrmann, "Von der östli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
