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Fluvisol
A fluvisol in the World Reference Base for Soil Resources (WRB) is a genetically young soil in alluvial deposits . Apart from river sediments, they also occur in lacustrine and marine deposits. Fluvisols correlate with fluvents and fluvaquents of the USDA soil taxonomy. The good natural fertility of most fluvisols and their attractive dwelling sites on river levees and higher parts in marine landscapes were recognized in prehistoric times. Fluvisols are found on alluvial plains, river fans, valleys and tidal marshes on all continents and in all climate zones. Under natural conditions periodical flooding is fairly common. The soils have a clear evidence of stratification. Soil horizons are weakly developed, but a distinct topsoil horizon may be present. Many dryland crops are grown on fluvisols, normally with some form of water control. On tropical Fluvisols with satisfactory irrigation and drainage paddy rice cultivation is widespread. Some coastal lowlands have fluvisols w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluvisol Profile
A fluvisol in the World Reference Base for Soil Resources (WRB) is a genetically young soil in alluvial deposits . Apart from river sediments, they also occur in lacustrine and marine deposits. Fluvisols correlate with fluvents and fluvaquents of the USDA soil taxonomy. The good natural fertility of most fluvisols and their attractive dwelling sites on river levees and higher parts in marine landscapes were recognized in prehistoric times. Fluvisols are found on alluvial plains, river fans, valleys and tidal marshes on all continents and in all climate zones. Under natural conditions periodical flooding is fairly common. The soils have a clear evidence of stratification. Soil horizons are weakly developed, but a distinct topsoil horizon may be present. Many dryland crops are grown on fluvisols, normally with some form of water control. On tropical Fluvisols with satisfactory irrigation and drainage paddy rice cultivation is widespread. Some coastal lowlands have fluvisols with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluvisol
A fluvisol in the World Reference Base for Soil Resources (WRB) is a genetically young soil in alluvial deposits . Apart from river sediments, they also occur in lacustrine and marine deposits. Fluvisols correlate with fluvents and fluvaquents of the USDA soil taxonomy. The good natural fertility of most fluvisols and their attractive dwelling sites on river levees and higher parts in marine landscapes were recognized in prehistoric times. Fluvisols are found on alluvial plains, river fans, valleys and tidal marshes on all continents and in all climate zones. Under natural conditions periodical flooding is fairly common. The soils have a clear evidence of stratification. Soil horizons are weakly developed, but a distinct topsoil horizon may be present. Many dryland crops are grown on fluvisols, normally with some form of water control. On tropical Fluvisols with satisfactory irrigation and drainage paddy rice cultivation is widespread. Some coastal lowlands have fluvisols w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Reference Base For Soil Resources
The World Reference Base for Soil Resources (WRB) is an international soil classification system for naming soils and creating legends for soil maps. The currently valid version is the fourth edition 2022. It is edited by a working group of the International Union of Soil Sciences (IUSS). WRB, 4th edition (2022) Background History Since the 19th century, several countries developed national soil classification systems. During the 20th century, the need for an international soil classification system became more and more obvious. From 1971 to 1981, the Food and Agriculture Organization ( FAO) and UNESCO published the Soil Map of the World, 10 volumes, scale 1 : 5 M). The Legend for this map, published in 1974 under the leadership of Rudi Dudal, became the FAO soil classification. Many ideas from national soil classification systems were brought together in this worldwide-applicable system, among them the idea of diagnostic horizons as established in the '7th approximation to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluvent
Entisols are soils defined in USDA soil taxonomy that do not show any profile development other than an A horizon. An entisol has no diagnostic horizons, and most are basically unaltered from their parent material, which can be unconsolidated sediment or rock. Entisols are the most abundant soil order, occupying about 16% of the global ice-free land area. Because of the diversity of their properties, suborders of entisols form individual Reference Soil Groups in the World Reference Base for Soil Resources (WRB): Psamments correlate with Arenosols and Fluvents with Fluvisols. Many Orthents belong to Regosols or Leptosols. Most Wassents and aquic subgroups of other suborders belong to the Gleysols. In Australia, most entisols are known as rudosols or tenosols. Causes of delayed or absent development * Unweatherable parent materials – sand, iron oxide, aluminium oxide, kaolinite clay. * Erosion – common on shoulder slopes; other kinds also important. * Deposition – contin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orinoco
The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers , with 76.3 percent of it in Venezuela and the remainder in Colombia. It is the fourth largest river in the world by discharge volume of water. The Orinoco River and its tributaries are the major transportation system for eastern and interior Venezuela and the Llanos of Colombia. The environment and wildlife in the Orinoco's basin are extremely diverse. Etymology The river's name is derived from the Warao term for "a place to paddle", itself derived from the terms ''güiri'' (paddle) and ''noko'' (place) i.e. a navigable place. History The mouth of the Orinoco River at the Atlantic Ocean was documented by Christopher Columbus on 1 August 1498, during his third voyage. Its source at the Cerro Delgado–Chalbaud, in the Parima range, was not explored until 453 years later, in 1951. The source, near the Venezuelan–Brazilian border, at ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niger
) , official_languages = , languages_type = National languagesRépublique du Niger, "Loi n° 2001-037 du 31 décembre 2001 fixant les modalités de promotion et de développement des langues nationales." L'aménagement linguistique dans le monde (accessed 21 September 2016) , languages = , religion_ref = , religion_year = 2012 , religion = , demonym = Nigerien , capital = Niamey , coordinates = , largest_city = Niamey , government_type = Unitary state, Unitary Semi-presidential s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nile
The Nile, , Bohairic , lg, Kiira , Nobiin language, Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered the List of rivers by length, longest river in the world, though this has been contested by research suggesting that the Amazon River is slightly longer.Amazon Longer Than Nile River, Scientists Say Of the world's major rivers, the Nile is one of the smallest, as measured by annual flow in cubic metres of water. About long, its drainage basin covers eleven countries: the Democratic Republic of the Congo, Tanzania, Burundi, Rwanda, Uganda, Kenya, Ethiopia, Erit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mississippi
Mississippi () is a state in the Southeastern region of the United States, bordered to the north by Tennessee; to the east by Alabama; to the south by the Gulf of Mexico; to the southwest by Louisiana; and to the northwest by Arkansas. Mississippi's western boundary is largely defined by the Mississippi River. Mississippi is the 32nd largest and 35th-most populous of the 50 U.S. states and has the lowest per-capita income in the United States. Jackson is both the state's capital and largest city. Greater Jackson is the state's most populous metropolitan area, with a population of 591,978 in 2020. On December 10, 1817, Mississippi became the 20th state admitted to the Union. By 1860, Mississippi was the nation's top cotton-producing state and slaves accounted for 55% of the state population. Mississippi declared its secession from the Union on January 9, 1861, and was one of the seven original Confederate States, which constituted the largest slaveholding states in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Africa
Central Africa is a subregion of the African continent comprising various countries according to different definitions. Angola, Burundi, the Central African Republic, Chad, the Democratic Republic of the Congo, the Republic of the Congo, Equatorial Guinea, Gabon, Rwanda, and São Tomé and Príncipe are members of the Economic Community of Central African States (ECCAS). Six of those states (the Central African Republic, Chad, the Republic of the Congo, Equatorial Guinea, and Gabon) are also members of the Economic and Monetary Community of Central Africa (CEMAC) and share a common currency, the Central African CFA franc. The African Development Bank defines Central Africa as the Central African Republic, Chad, the Democratic Republic of the Congo, the Republic of the Congo, Equatorial Guinea, and Gabon. Middle Africa is an analogous term used by the United Nations in its geoscheme for Africa. It includes the same countries as the African Development Bank's definiti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mekong
The Mekong or Mekong River is a trans-boundary river in East Asia and Southeast Asia. It is the world's twelfth longest river and the third longest in Asia. Its estimated length is , and it drains an area of , discharging of water annually. From the Tibetan Plateau the river runs through China, Myanmar, Laos, Thailand, Cambodia, and Vietnam. The extreme seasonal variations in flow and the presence of rapids and waterfalls in the Mekong make navigation difficult. Even so, the river is a major trade route between western China and Southeast Asia. Names The Mekong was originally called ''Mae Nam Khong'' from a contracted form of Tai shortened to ''Mae Khong''. In Thai and Lao, ''Mae Nam'' ("Mother of Water ) is used for large rivers and ''Khong'' is the proper name referred to as "River Khong". However, ''Khong'' is an archaic word meaning "river", loaned from Austroasiatic languages, such as Vietnamese ''sông'' (from *''krong'') and Mon ''kruŋ'' "river", which led to Chine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indus
The Indus ( ) is a transboundary river of Asia and a trans-Himalayan river of South and Central Asia. The river rises in mountain springs northeast of Mount Kailash in Western Tibet, flows northwest through the disputed region of Kashmir, Quote: "Kashmir, region of the northwestern Indian subcontinent. It is bounded by the Uygur Autonomous Region of Xinjiang to the northeast and the Tibet Autonomous Region to the east (both parts of China), by the Indian states of Himachal Pradesh and Punjab to the south, by Pakistan to the west, and by Afghanistan to the northwest. The northern and western portions are administered by Pakistan and comprise three areas: Azad Kashmir, Gilgit, and Baltistan, ... The southern and southeastern portions constitute the Indian state of Jammu and Kashmir. The Indian- and Pakistani-administered portions are divided by a "line of control" agreed to in 1972, although neither country recognizes it as an international boundary. In addition, China be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
