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Purus Várzea
The Purus várzea (NT0156) is an ecoregion of seasonally flooded várzea forest in the central Amazon basin. It is part of the Amazon biome. The ecoregion is home to a vegetation adapted to floods of up to that may last for eight months. There is a great variety of fish and birds, but relatively fewer mammals. Ground-dwelling mammals must migrate to higher ground during the flood season. Threats include logging, cattle farming, over-fishing and mercury pollution from gold mining. Location The Purus várzea is a low-lying region of the central Amazon basin that is seasonally flooded. It covers of eastern Colombia and western Brazil. It extends along most of the Juruá, central Purus, and Caquetá ( Japurá) rivers and their tributaries. In the east it reaches the confluence of the Japurá and Solimões Rivers. Urban centers in or around the region are Tefé, Tabatinga and Carauarí. To the southeast the varzea adjoins the Purus–Madeira moist forests, and to the northeas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mapinguari National Park
Mapinguari National Park ( pt, Parque Nacional Mapinguari) is a national park in the states of Rondônia and Amazonas, Brazil. It covers a large area of Amazon rainforest. The boundaries have been adjusted several times. Location The Mapinguari National Park is in the municipalities of Canutama (40%) and Lábrea (50%) in Amazonas and the municipality of Porto Velho (11%) in Rondônia. It has an area of . The park is in the Solimões-Amazonas sedimentary basin, in the south Amazon depression. The relief is an extensive pediplain with river terraces, floodplains and meander traces. Altitudes range from above sea level. It is drained by streams or rivers feeding the left of the Madeira River and the right of the Purus River. The main rivers within the park are the Açuã, Mucuim, Inacorrã, Umari, Ciriquiqui, Punicici, Coari, Anaiquê and Coti. Environment The park is in the Amazon biome. Average annual rainfall is . Temperatures range from with an average of . Vegetat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japurá–Solimões–Negro Moist Forests
The Japurá–Solimões–Negro moist forests (NT0132) is an ecoregion of tropical moist broad leaf forest in the Amazon biome. Location The Japurá–Solimoes–Negro moist forests ecoregion is named for the Japurá, Solimões, and Negro rivers. Almost all of the ecoregion is in the central northern part of the Brazilian Amazon basin, with a small portion in Colombia. It has an area of . Conservation units include the Jaú National Park and the Mamirauá Sustainable Development Reserve. The ecoregion lies on the lowland plateau in the interfluvial between the Rio Negro and the Solimões River. In Colombia the region skirts the foothills of the Guiana Shield to the northwest, and contains the lower Vaupés River basin and the land south of the Guainía River, the name of the upper Rio Negro in Colombia. The region is then bounded by the Rio Negro along the border with Venezuela and into Brazil to its confluence with the Solimões at Manaus. The southern border is defined ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropical And Subtropical Moist Broadleaf Forests
Tropical and subtropical moist broadleaf forests (TSMF), also known as tropical moist forest, is a subtropical and tropical forest habitat type defined by the World Wide Fund for Nature. Description TSMF is generally found in large, discontinuous patches centered on the equatorial belt and between the Tropic of Cancer and Tropic of Capricorn, TSMF are characterized by low variability in annual temperature and high levels of rainfall of more than annually. Forest composition is dominated by evergreen and semi-deciduous tree species. These trees number in the thousands and contribute to the highest levels of species diversity in any terrestrial major habitat type. In general, biodiversity is highest in the forest canopy. The canopy can be divided into five layers: overstory canopy with emergent crowns, a medium layer of canopy, lower canopy, shrub level, and finally understory. These forests are home to more species than any other terrestrial ecosystem: Half of the world' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bar (river Morphology)
A bar in a river is an elevated region of sediment (such as sand or gravel) that has been deposited by the flow. Types of bars include mid-channel bars (also called braid bars and common in braided rivers), point bars (common in meandering rivers), and mouth bars (common in river deltas). The locations of bars are determined by the geometry of the river and the flow through it. Bars reflect sediment supply conditions, and can show where sediment supply rate is greater than the transport capacity. A mid-channel bar, is also often referred to as a braid bar because they are often found in braided river channels. Braided river channels are broad and shallow and found in areas where sediment is easily eroded like at a glacial outwash, or at a mountain front with high sediment loads. These types of river systems are associated with high slope, sediment supply, stream power, shear stress, and bed load transport rates. Braided rivers have complex and unpredictable channel patter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swale (landform)
A swale is a shady spot, or a sunken or marshy place. In US usage in particular, it is a shallow channel with gently sloping sides. Such a swale may be either natural or human-made. Artificial swales are often infiltration basins, designed to manage water runoff, filter pollutants, and increase rainwater infiltration. Bioswales are swales that involve the inclusion of plants or vegetation in their construction, specifically. On land This swale concept has also been popularized as a rainwater harvesting and soil conservation strategy by Bill Mollison, David Holmgren, and other advocates of permaculture. In this context it is usually a water-harvesting ditch on contour, also called a ''contour bund''. Swales as used in permaculture are designed to slow and capture runoff by spreading it horizontally across the landscape (along an elevation contour line), facilitating runoff infiltration into the soil. This archetypal form of swale is a dug-out, sloped, often grassed or reede ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Levee
A levee (), dike (American English), dyke (Commonwealth English), embankment, floodbank, or stop bank is a structure that is usually earthen and that often runs parallel to the course of a river in its floodplain or along low-lying coastlines. The purpose of a levee is to keep the course of rivers from changing and to protect against flooding of the area adjoining the river or coast. Levees can be naturally occurring ridge structures that form next to the bank of a river, or be an artificially constructed fill or wall that regulates water levels. Ancient civilizations in the Indus Valley, ancient Egypt, Mesopotamia and China all built levees. Today, levees can be found around the world, and failures of levees due to erosion or other causes can be major disasters. Etymology Speakers of American English (notably in the Midwest and Deep South) use the word ''levee'', from the French word (from the feminine past participle of the French verb , 'to raise'). It originat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxbow Lake
An oxbow lake is a U-shaped lake or pool that forms when a wide meander of a river is cut off, creating a free-standing body of water. In South Texas, oxbows left by the Rio Grande are called '' resacas''. In Australia, oxbow lakes are called billabongs. The word "oxbow" can also refer to a U-shaped bend in a river or stream, whether or not it is cut off from the main stream. Geology An oxbow lake forms when a meandering river erodes through the neck of one of its meanders. This takes place because meanders tend to grow and become more curved over time. The river then follows a shorter course that bypasses the meander. The entrances to the abandoned meander eventually silt up, forming an oxbow lake. Because oxbow lakes are stillwater lakes, with no current flowing through them, the entire lake gradually silts up, becoming a bog or swamp and then evaporating completely. When a river reaches a low-lying plain, often in its final course to the sea or a lake, it meanders w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holocene
The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene has been identified with the current warm period, known as MIS 1. It is considered by some to be an interglacial period within the Pleistocene Epoch, called the Flandrian interglacial.Oxford University Press – Why Geography Matters: More Than Ever (book) – "Holocene Humanity" section https://books.google.com/books?id=7P0_sWIcBNsC The Holocene corresponds with the rapid proliferation, growth and impacts of the human species worldwide, including all of its written history, technological revolutions, development of major civilizations, and overall significant transition towards urban living in the present. The human impact on modern-era Earth and its ecosystems may be considered of global ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andes
The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S latitude), and has an average height of about . The Andes extend from north to south through seven South American countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, and Argentina. Along their length, the Andes are split into several ranges, separated by intermediate depressions. The Andes are the location of several high plateaus—some of which host major cities such as Quito, Bogotá, Cali, Arequipa, Medellín, Bucaramanga, Sucre, Mérida, El Alto and La Paz. The Altiplano plateau is the world's second-highest after the Tibetan plateau. These ranges are in turn grouped into three major divisions based on climate: the Tropical Andes, the Dry Andes, and the Wet Andes. The Andes Mountains are the highest m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whitewater River (river Type)
A whitewater river is classified based on its chemistry, sediments and water colour. Whitewater rivers have high levels of suspended sediments, giving the water a pH that is near-neutral, a high electric conductivity and a pale muddy, coffee and cream-like colour. Whitewater rivers are of great ecological importance and are important to local fisheries. The major seasonal Amazonian floodplains known as '' várzea'' receive their water from them. The best-known whitewater rivers are Amazonian and have their source in the Andes, but there are also whitewater rivers elsewhere in South America and in other continents. Amazonian rivers fall into three main categories: whitewater, blackwater and clearwater. This classification system was first proposed by Alfred Russel Wallace in 1853 based on water colour, but the types were more clearly defined according to chemistry and physics by from the 1950s to the 1980s. Although many Amazonian rivers fall clearly into one of these categor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monte Alegre Várzea
The Monte Alegre várzea (NT0141) is an ecoregion of seasonally flooded várzea forest along the Amazon River in the Amazon biome. Location The várzea forests of this ecoregion extend along the low, seasonally flooded rivers of the central and lower basin of the Amazon River, including a large part of the Madeira River basin, the mouth of the Purus River, tributaries of these rivers and an isolated patch of várzea along the Mamoré River between Bolivia and Brazil. Major population centers in or near the ecoregion are Manaus, Itacoatiara, Coari and Óbidos. The ecoregion adjoins the Madeira-Tapajós moist forests to the southeast and the Uatuma-Trombetas moist forests and Japurá-Solimões-Negro moist forests to the north. The Purus-Madeira moist forests lie to the west of the Madeira and the south of the Amazon. The Purus várzea is upstream along the Solimões and Purus rivers and their tributaries. The Gurupa várzea is downstream along the Amazon. Physical Eleva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juruá–Purus Moist Forests
The Juruá–Purus moist forests (NT0133) is an ecoregion in northwest Brazil in the Amazon biome. The terrain is very flat and soils are poor. The rivers flood annually. There are no roads in the region, and the dense rainforest is relatively intact, although plans to extend the Trans-Amazonian Highway through the region would presumably cause widespread damage to the habitat. Location The Juruá–Purus moist forests ecoregion is in the state of Amazonas in northwest Brazil to the south of the Solimões, or upper Amazon River. It has an area of . The ecoregion is bounded to the north, east and south by stretches of the Purus várzea ecoregion along the Solimões and Purus rivers. The ecoregion contains the Juruá River, which has typical flora and fauna. Urban centers include Carauari, Tefé, Coari and Jutaí. The várzea, or flooded forest, extends along rivers within the ecoregion. To the west the Juruá–Purus moist forests adjoin the Southwest Amazon moist forests. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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