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Irrigation Management
Irrigation is the artificial ''exploitation'' and ''distribution'' of water at ''project level'' aiming at ''application'' of water at ''field level'' to agricultural crops in dry areas or in periods of scarce rainfall to assure or improve crop production. This article discusses organizational forms and means of management of irrigation water at project (system) level. History Scholars such as Julian H. Steward and Karl August Wittfogel have seen the management of irrigation as a crucial factor in the development of many early states (hydraulic empires). Water management The most important physical elements of an ''irrigation project'' are ''land'' and ''water''. In accordance with the propriety relations of these elements there may be different types of water management:''Effectiveness and Social/Environmental Impacts of Irrigation Projects: a Review''. In: Annual Report 1988, International Institute for Land Reclamation and Improvement (ILRI), Wageningen, The Netherlands, pp. 18 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irrigation
Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow Crop, crops, Landscape plant, landscape plants, and Lawn, lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has been developed by many cultures around the world. Irrigation helps to grow crops, maintain landscapes, and revegetation, revegetate disturbed soils in dry areas and during times of below-average rainfall. In addition to these uses, irrigation is also employed to protect crops from frost, suppress weed growth in grain fields, and prevent soil consolidation. It is also used to cool livestock, reduce dust, dispose of sewage, and support mining operations. Drainage, which involves the removal of surface and sub-surface water from a given location, is often studied in conjunction with irrigation. There are several methods of irrigation that differ in how water is supplied to plants. Surface irrigation, also known as gravity irri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plantations
A plantation is an agricultural estate, generally centered on a plantation house, meant for farming that specializes in cash crops, usually mainly planted with a single crop, with perhaps ancillary areas for vegetables for eating and so on. The crops that are grown include cotton, coffee, tea, cocoa, sugar cane, opium, sisal, oil seeds, oil palms, fruits, rubber trees and forest trees. Protectionist policies and natural comparative advantage have sometimes contributed to determining where plantations are located. In modern use the term is usually taken to refer only to large-scale estates, but in earlier periods, before about 1800, it was the usual term for a farm of any size in the southern parts of British North America, with, as Noah Webster noted, "farm" becoming the usual term from about Maryland northwards. It was used in most British colonies, but very rarely in the United Kingdom itself in this sense. There, as also in America, it was used mainly for tree plantations, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Well
A well is an excavation or structure created in the ground by digging, driving, or drilling to access liquid resources, usually water. The oldest and most common kind of well is a water well, to access groundwater in underground aquifers. The well water is drawn up by a pump, or using containers, such as buckets or large water bags that are raised mechanically or by hand. Water can also be injected back into the aquifer through the well. Wells were first constructed at least eight thousand years ago and historically vary in construction from a simple scoop in the sediment of a dry watercourse to the qanats of Iran, and the stepwells and sakiehs of India. Placing a lining in the well shaft helps create stability, and linings of wood or wickerwork date back at least as far as the Iron Age. Wells have traditionally been sunk by hand digging, as is still the case in rural areas of the developing world. These wells are inexpensive and low-tech as they use mostly manual labour, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
License
A license (or licence) is an official permission or permit to do, use, or own something (as well as the document of that permission or permit). A license is granted by a party (licensor) to another party (licensee) as an element of an agreement between those parties. In the case of a license issued by a government, the license is obtained by applying for it. In the case of a private party, it is by a specific agreement, usually in writing (such as a lease or other contract). The simplest definition is "A license is a promise not to sue," because a license usually either permits the licensed party to engage in an activity which is illegal, and subject to prosecution, without the license (e.g. fishing, driving an automobile, or operating a broadcast radio or television station), or it permits the licensed party to do something that would violate the rights of the licensing party (e.g. make copies of a copyrighted work), which, without the license, the licensed party could be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flow Measurement
Flow measurement is the quantification of bulk fluid movement. Flow can be measured in a variety of ways. The common types of flowmeters with industrial applications are listed below: * a) Obstruction type (differential pressure or variable area) * b) Inferential (turbine type) * c) Electromagnetic * d) Positive-displacement flowmeters, which accumulate a fixed volume of fluid and then count the number of times the volume is filled to measure flow. * e) Fluid dynamic (vortex shedding) * f) Anemometer * g) Ultrasonic * h) Mass flowmeter ( Coriolis force). Flow measurement methods other than positive-displacement flowmeters rely on forces produced by the flowing stream as it overcomes a known constriction, to indirectly calculate flow. Flow may be measured by measuring the velocity of fluid over a known area. For very large flows, tracer methods may be used to deduce the flow rate from the change in concentration of a dye or radioisotope. Kinds and units of measurement Both gas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tariff
A tariff is a tax imposed by the government of a country or by a supranational union on imports or exports of goods. Besides being a source of revenue for the government, import duties can also be a form of regulation of foreign trade and policy that taxes foreign products to encourage or safeguard domestic industry. ''Protective tariffs'' are among the most widely used instruments of protectionism, along with import quotas and export quotas and other non-tariff barriers to trade. Tariffs can be fixed (a constant sum per unit of imported goods or a percentage of the price) or variable (the amount varies according to the price). Taxing imports means people are less likely to buy them as they become more expensive. The intention is that they buy local products instead, boosting their country's economy. Tariffs therefore provide an incentive to develop production and replace imports with domestic products. Tariffs are meant to reduce pressure from foreign competition and reduce th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Delivery Practices
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a solvent). It is vital for all known forms of life, despite not providing food, energy or organic micronutrients. Its chemical formula, H2O, indicates that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds. The hydrogen atoms are attached to the oxygen atom at an angle of 104.45°. "Water" is also the name of the liquid state of H2O at standard temperature and pressure. A number of natural states of water exist. It forms precipitation in the form of rain and aerosols in the form of fog. Clouds consist of suspended droplets of water and ice, its solid state. When finely divided, crystalline ice may precipitate in the form of snow. The gaseous state of water is steam or water vapor. Water cov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Environmental Impact Of Irrigation
The environmental effects of irrigation relate to the changes in quantity and quality of soil and water as a result of irrigation and the subsequent effects on natural and social conditions in river basins and downstream of an irrigation scheme. The effects stem from the altered hydrological conditions caused by the installation and operation of the irrigation scheme. Amongst some of these problems is depletion of underground aquifers through overdrafting. Soil can be over-irrigated due to poor distribution uniformity or management wastes water, chemicals, and may lead to water pollution. Over-irrigation can cause deep drainage from rising water tables that can lead to problems of irrigation salinity requiring watertable control by some form of subsurface land drainage. However, if the soil is under irrigated, it gives poor soil salinity control which leads to increased soil salinity with the consequent buildup of toxic salts on the soil surface in areas with high evaporation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weir
A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the river level. Weirs are also used to control the flow of water for outlets of lakes, ponds, and reservoirs. There are many weir designs, but commonly water flows freely over the top of the weir crest before cascading down to a lower level. Etymology There is no single definition as to what constitutes a weir and one English dictionary simply defines a weir as a small dam, likely originating from Middle English ''were'', Old English ''wer'', derivative of root of ''werian,'' meaning "to defend, dam". Function Commonly, weirs are used to prevent flooding, measure water discharge, and help render rivers more navigable by boat. In some locations, the terms dam and weir are synonymous, but normally there is a clear distinction made between the structures. Usually, a dam is designed specifically to impound water behind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Right
Water right in water law refers to the right of a user to use water from a water source, e.g., a river, stream, pond or source of groundwater. In areas with plentiful water and few users, such systems are generally not complicated or contentious. In other areas, especially arid areas where irrigation is practiced, such systems are often the source of conflict, both legal and physical. Some systems treat surface water and ground water in the same manner, while others use different principles for each. Types of water right Understanding ‘Water Rights’ first requires consideration of the context and origin of the ‘right’ being discussed, or asserted. Traditionally, a water rights refers to the utilization of water as an element supporting basic human needs like drinking or irrigation. Water Rights could also include the physical occupancy of waterways for purposes of travel, commerce and even recreational pursuits. The legal principles and doctrines that forms the basis o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sudan Gezira Plain 1997
Sudan ( or ; ar, السودان, as-Sūdān, officially the Republic of the Sudan ( ar, جمهورية السودان, link=no, Jumhūriyyat as-Sūdān), is a country in Northeast Africa. It shares borders with the Central African Republic to the southwest, Chad to the west, Egypt to the north, Eritrea to the northeast, Ethiopia to the southeast, Libya to the northwest, South Sudan to the south and the Red Sea. It has a population of 45.70 million people as of 2022 and occupies 1,886,068 square kilometres (728,215 square miles), making it Africa's List of African countries by area, third-largest country by area, and the third-largest by area in the Arab League. It was the largest country by area in Africa and the Arab League until the 2011 South Sudanese independence referendum, secession of South Sudan in 2011, since which both titles have been held by Algeria. Its Capital city, capital is Khartoum and its most populated city is Omdurman (part of the metropolitan area of Khar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Land Reform
Land reform is a form of agrarian reform involving the changing of laws, regulations, or customs regarding land ownership. Land reform may consist of a government-initiated or government-backed property redistribution, generally of agricultural land. Land reform can, therefore, refer to transfer of ownership from the more powerful to the less powerful, such as from a relatively small number of wealthy or noble owners with extensive land holdings (e.g., plantations, large ranches, or agribusiness plots) to individual ownership by those who work the land. Such transfers of ownership may be with or without compensation; compensation may vary from token amounts to the full value of the land. Land reform may also entail the transfer of land from individual ownership—even peasant ownership in smallholdings—to government-owned collective farms; it has also, in other times and places, referred to the exact opposite: division of government-owned collective farms into smallholdings. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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