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Dahomey Gap
In West Africa, the Dahomey Gap refers to the portion of the Guinean forest-savanna mosaic that extends all the way to the coast in Benin, Togo, and Ghana, thus separating the forest zone that covers much of the south of the region into two separate parts. The forest region west of the gap is called the Upper Guinean forests or Guinean forest zone, and the portion east of the gap is called the Lower Guinean forests, Lower Guinean-Congolian forests, or Congolian Forest Zone. The major cities in the Gap are Accra, Lomé, Cotonou and Porto-Novo. Several other cities, such as Kumasi, exist on the fringe of the Gap. Causes of dryness The dryness of the Dahomey Gap is unusual, given that it lies surrounded by a very wet monsoon belt on all sides, without mountains to block moisture. Yet, Accra, which is in the heart of the Gap, receives only of rainfall per year — less than half the amount needed to sustain tropical rainforest (which would be expected at a latitude of 6° N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
West Africa
West Africa, also known as Western Africa, is the westernmost region of Africa. The United Nations geoscheme for Africa#Western Africa, United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone, and Togo, as well as Saint Helena, Ascension and Tristan da Cunha (United Kingdom Overseas Territories, United Kingdom Overseas Territory).Paul R. Masson, Catherine Anne Pattillo, "Monetary union in West Africa (ECOWAS): is it desirable and how could it be achieved?" (Introduction). International Monetary Fund, 2001. The population of West Africa is estimated at around million people as of , and at 381,981,000 as of 2017, of which 189,672,000 were female and 192,309,000 male.United Nations Department of Economic and Social Affairs, Population Division (2017). World Population Prospects: The 2017 Revision, custom data acquired via webs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Harmattan
The Harmattan is a season in West Africa that occurs between the end of November and the middle of March. It is characterized by the dry and dusty northeasterly trade wind, of the same name, which blows from the Sahara over West Africa into the Gulf of Guinea. The name is related to the word in the Twi language. The temperature is cold mostly at night in some places but can be very hot in certain places during daytime. Generally, temperature differences can also depend on local circumstances. The Harmattan blows during the dry season, which occurs during the months with the lowest sun. In this season, the subtropical ridge of high pressure stays over the central Sahara and the low-pressure Intertropical Convergence Zone (ITCZ) stays over the Gulf of Guinea. On its passage over the Sahara, the Harmattan picks fine dust and sand particles (between 0.5 and 10 microns). It is also known as the "doctor wind", because of its invigorating dryness compared with humid tropical air. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Aplocheiloidei
Aplocheiloidei is a suborder of the Order (biology), order Cyprinodontiformes consisting of three Family (biology), families which are commonly known as killifishes. Families The three families within the suborder Aplocheiloidei are: * Aplocheilidae Bleeker, 1859 * Nothobranchiidae Samuel Garman, Garman, 1895 * Rivulidae George S. Myers, Myers, 1925 The only known fossil member of the suborder is the Late Miocene-aged ''Kenyaichthys'' from the Lukeino Formation of Kenya, which is the only known member of the family Kenyaichthyidae Altner & Reichenbacher, 2015. Proposed taxonomy Some authorities have lumped the three families into a single family, Aplocheilidae, a well-established name, chosen for its stability in usage over time, and to avoid the impact of a new name at the family rank for a popular aquarium fish group. Under this proposal, the Aplocheilidae includes three subfamilies: Aplocheilinae for the species from Asia, Madagascar and the Seychelles; Cynolebiidae, Cynolebi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Evaporation
Evaporation is a type of vaporization that occurs on the Interface (chemistry), surface of a liquid as it changes into the gas phase. A high concentration of the evaporating substance in the surrounding gas significantly slows down evaporation, such as when humidity affects rate of evaporation of water. When the molecules of the liquid collide, they transfer energy to each other based on how they collide. When a molecule near the surface absorbs enough energy to overcome the vapor pressure, it will escape and enter the surrounding air as a gas. When evaporation occurs, the energy removed from the vaporized liquid will reduce the temperature of the liquid, resulting in evaporative cooling. On average, only a fraction of the molecules in a liquid have enough heat energy to escape from the liquid. The evaporation will continue until an equilibrium is reached when the evaporation of the liquid is equal to its condensation. In an enclosed environment, a liquid will evaporate unt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Savanna
A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses. Four savanna forms exist; ''savanna woodland'' where trees and shrubs form a light canopy, ''tree savanna'' with scattered trees and shrubs, ''shrub savanna'' with distributed shrubs, and ''grass savanna'' where trees and shrubs are mostly nonexistent.Smith, Jeremy M.B.. "savanna". Encyclopedia Britannica, 5 Sep. 2016, https://www.britannica.com/science/savanna/Environment. Accessed 17 September 2022. Savannas maintain an open canopy despite a high tree density. It is often believed that savannas feature widely spaced, scattered trees. However, in many savannas, tree densities are higher and trees are more regularly spaced than in forests.Manoel Cláudio da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Wisconsin
Wisconsin ( ) is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest of the United States. It borders Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. With a population of about 6 million and an area of about 65,500 square miles, Wisconsin is the List of U.S. states and territories by population, 20th-largest state by population and the List of U.S. states and territories by area, 23rd-largest by area. It has List of counties in Wisconsin, 72 counties. Its List of municipalities in Wisconsin by population, most populous city is Milwaukee; its List of capitals in the United States, capital and second-most populous city is Madison, Wisconsin, Madison. Other urban areas include Green Bay, Wisconsin, Green Bay, Kenosha, Wisconsin, Kenosha, Racine, Wisconsin, Racine, Eau Claire, Wisconsin, Eau Claire, and the Fox Cities. Geography of Wiscon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Madison, Wisconsin
Madison is the List of capitals in the United States, capital city of the U.S. state of Wisconsin. It is the List of municipalities in Wisconsin by population, second-most populous city in the state, with a population of 269,840 at the 2020 United States census, 2020 census. The Madison metropolitan area had 680,796 residents. Centrally located on an isthmus between Lakes Lake Mendota, Mendota and Lake Monona, Monona, the vicinity also encompass Lakes Lake Wingra, Wingra, Lake Kegonsa, Kegonsa and Lake Waubesa, Waubesa. Madison was founded in 1836 and is named after American Founding Fathers of the United States, Founding Father and President James Madison. It is the county seat of Dane County. As the state capital, Madison is home to government chambers including the Wisconsin State Capitol building. It is also home to the University of Wisconsin–Madison, the flagship campus of the University of Wisconsin System. Major companies in the area include American Family Insurance, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Parallel (geometry)
In geometry, parallel lines are coplanar infinite straight line (geometry), lines that do not intersecting lines, intersect at any point. Parallel planes are plane (geometry), planes in the same three-dimensional space that never meet. ''Parallel curves'' are curves that do not tangent, touch each other or intersect and keep a fixed minimum distance. In three-dimensional Euclidean space, a line and a plane that do not share a point are also said to be parallel. However, two noncoplanar lines are called ''skew lines''. Line segments and Euclidean vectors are parallel if they have the same direction (geometry), direction or opposite direction (geometry), opposite direction (not necessarily the same length). Parallel lines are the subject of Euclid's parallel postulate. Parallelism is primarily a property of affine geometry, affine geometries and Euclidean geometry is a special instance of this type of geometry. In some other geometries, such as hyperbolic geometry, lines can have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Dry Season
The dry season is a yearly period of low rainfall, especially in the tropics. The weather in the tropics is dominated by the tropical rain belt, which moves from the northern to the southern tropics and back over the course of the year. The temperate counterpart to the tropical dry season is summer or winter. Rain belt The tropical rain belt lies in the southern hemisphere roughly from November to March; during that time the northern tropics have a dry season with sparser precipitation, and days are typically sunny throughout. From May to September, the rain belt lies in the northern hemisphere, and the southern tropics have their dry season. Under the Köppen climate classification, for tropical climates, a dry season month is defined as a month when average precipitation is below . The rain belt reaches roughly as far north as the Tropic of Cancer and as far south as the Tropic of Capricorn. Near these latitudes, there is one wet season and one dry season annually. At the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Aspect (geography)
In physical geography and physical geology, aspect (also known as exposure) is the compass direction or azimuth that a terrain surface faces. For example, a slope landform on the eastern edge of the Rockies toward the Great Plains is described as having an ''easterly aspect''. A slope which falls down to a deep valley on its western side and a shallower one on its eastern side has a ''westerly aspect'' or is a ''west-facing slope''. The direction a slope faces can affect the physical and biotic features of the slope, known as a slope effect. The term aspect can also be used to describe a related distinct concept: the horizontal alignment of a coastline. Here, the aspect is the direction which the coastline is facing towards the sea. For example, a coastline with sea to the northeast (as in most of Queensland) has a ''northeasterly aspect''. Aspect is complemented by '' grade'' (or inclination angle) to characterize the surface gradient. Importance Aspect can have a str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Liberia
Liberia, officially the Republic of Liberia, is a country on the West African coast. It is bordered by Sierra Leone to Liberia–Sierra Leone border, its northwest, Guinea to Guinea–Liberia border, its north, Ivory Coast to Ivory Coast–Liberia border, its east, and the Atlantic Ocean to its south and southwest. It has a population of around 5.5million and covers an area of . The official language is English. Languages of Liberia, Over 20 indigenous languages are spoken, reflecting the country's ethnic and cultural diversity. The capital and largest List of cities in Liberia, city is Monrovia. Liberia began in the early 19th century as a project of the American Colonization Society (ACS), which believed that black people would face better chances for freedom and prosperity in Africa than in the United States. Between 1822 and the outbreak of the American Civil War in 1861, more than 15,000 freed and free-born African Americans, along with 3,198 Afro-Caribbeans, relocated to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Sierra Leone
Sierra Leone, officially the Republic of Sierra Leone, is a country on the southwest coast of West Africa. It is bordered to the southeast by Liberia and by Guinea to the north. Sierra Leone's land area is . It has a tropical climate and environments ranging from savannas to rainforests. As of the 2023 census, Sierra Leone has a population of 8,460,512. Freetown is its capital and largest city. Sierra Leone is a presidential republic, with a unicameral parliament and a directly elected president. It is a secular state. Its Constitution of Sierra Leone, constitution provides for the separation of state and religion and freedom of conscience. Muslims constitute three-quarters of the population, and there is a significant Christian minority. Notably, religious tolerance is very high. Sierra Leone's current territorial configuration was established in two phases: in 1808, the coastal Sierra Leone Colony and Protectorate, Sierra Leone Colony was founded as a place to resettle retu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
