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Stream Pool
In hydrology, a stream pool is a stretch of a river or stream in which the water depth is above average and the water velocity is below average. Formation A stream pool may be bedded with sediment or armoured with gravel, and in some cases the pool formations may have been formed as basins in exposed bedrock formations. Plunge pools, or plunge basins, are stream pools formed by the action of waterfalls. Pools are often formed on the outside of a bend in a meandering river. Dynamics The depth and lack of water velocity often leads to stratification in stream pools, especially in warmer regions. In warm arid regions of the Western United States, surface waters were found to be 3–9 °C higher than those at the bottom Habitat This portion of a stream often provides a specialized aquatic ecosystem habitat for organisms that have difficulty feeding or navigating in swifter reaches of the stream or in seasonally warmer water. Such pools can be important fish habitat, espec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piva
Piva may refer to: Locations * Piva (Drina), a river in Montenegro and Bosnia and Herzegovina * Piva, Montenegro, a region in Montenegro and tribe * Lake Piva, a reservoir in Montenegro * Piva River, Bougainville, Papua New Guinea * Piva Trail, Bougainville, Papua New Guinea ** Battle for Piva Trail, 1943 Other * Piva language, a member of the Piva-Banoni languages * Piva (bagpipe), an Italian folk instrument * Piva (dance) ''Piva'' is an Italian Renaissance dance that may have originated from a peasant dance to the accompaniment of bagpipes. In 15th-century sources it is described as the fastest version of the basse danse. Antonio Cornazzano, for example, in his '' ..., a Renaissance dance * Primrose International Viola Archive, or PIVA, a collection of viola music at Brigham Young University {{disambig, geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redband Trout
Redband trout are a group of three recognized subspecies of rainbow trout (''Oncorhynchus mykiss''). They occur in three distinct regions in Pacific basin tributaries and endorheic basins in the western United States. The three subspecies are the Columbia River redband trout (''O. m. gairdneri''), the McCloud River redband trout (''O. m. stonei'') and the Great Basin redband trout (''O. m. newberrii''). The Columbia River redband trout is found in the Columbia River and its tributaries in Montana, Oregon, Washington and Idaho. Anadromous populations of ''O. m. gairdneri'' are known as redband steelhead. The McCloud River redband trout is found in small tributaries of the McCloud River and Pit River which are tributaries of California's Sacramento River. The Great Basin redband trout is found in seven distinct basins in southeastern Oregon, and parts of California and Nevada on the periphery of the Great Basin. Redband trout have often been confused with cutthroat trout (Onc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Streams
A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long, large streams are usually called rivers, while smaller, less voluminous and more intermittent river, intermittent streams are known, amongst others, as brook, creek, rivulet, rill, run, tributary, feeder, freshet, narrow river, and streamlet. The flow of a stream is controlled by three inputs – surface runoff (from precipitation or meltwater), daylighting (streams), daylighted subterranean river, subterranean water, and surfaced groundwater (Spring (hydrology), spring water). The surface and subterranean water are highly variable between periods of rainfall. Groundwater, on the other hand, has a relatively constant input and is controlled more by long-term patterns of pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Pools
Nature is an inherent character or constitution, particularly of the Ecosphere (planetary), ecosphere or the universe as a whole. In this general sense nature refers to the Scientific law, laws, elements and phenomenon, phenomena of the physical world, including life. Although humans are part of nature, human activity or humans as a whole are often described as at times at odds, or outright Anthropocentrism, separate and even superior to nature. During the advent of modern scientific method in the last several centuries, nature became the passive reality, organized and moved by divine laws. With the Industrial Revolution, nature increasingly became seen as the part of reality deprived from intentional intervention: it was hence considered as sacred by some traditions (Jean-Jacques Rousseau, Rousseau, American transcendentalism) or a mere decorum for divine providence or human history (Hegel, Marx). However, a vitalist vision of nature, closer to the pre-Socratic one, got reborn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Waterfalls By Type
The following is a list of waterfalls by type. * Plunge: Water descends vertically, losing contact with the bedrock surface.What is a Waterfall? archived fro the original 2011-07-18, retrieved 2012-07-18 * Horsetail: Descending water maintains some contact with bedrock. * Cataract: A large, powerful waterfall. * Multi-step: A series of waterfalls one after another of roughly the same size each with its own sunken plunge pool. * Block: Water descends from a relatively wide stream or river. * Cascade: Water descends a series of rock steps. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Waterfalls By Flow Rate
This list of waterfalls by flow rate includes all waterfalls which are known to have an average flow rate or discharge of at least . The waterfalls in this list are those for which there is verifiable information, and the list should not be assumed to be a complete list of waterfalls which would otherwise qualify as globally significant based on this metric. Largest extant waterfalls Largest historic waterfalls This list comprises the waterfalls which have ceased to exist due to the impoundment of their river(s) by a dam, or due to the diversion of the watercourse. Prehistoric waterfalls See also *Waterfall *List of rivers by discharge *List of waterfalls * List of waterfalls by height * List of waterfalls by type *Orders of magnitude (power) This page lists examples of the power in watts produced by various sources of energy. They are grouped by orders of magnitude from small to large. Below 1 W 1 to 102 W 103 to 108 W The productive capacity of electrical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stream Gradient
Stream gradient (or stream slope) is the grade (or slope) of a stream. It is measured by the ratio of drop in elevation and horizontal distance. It is a dimensionless quantity, usually expressed in units of meters per kilometer (m/km) or feet per mile (ft/mi); it may also be expressed in percent (%). The world average river reach slope is 2.6 m/km or 0.26%; a slope smaller than 1% and greater than 4% is considered gentle and steep, respectively. Stream gradient may change along the stream course. An average gradient can be defined, known as the relief ratio, which gives the average drop in elevation per unit length of river. The calculation is the difference in elevation between the river's source and the river terminus (confluence or mouth) divided by the total length of the river or stream. Hydrology and geology A high gradient indicates a steep slope and rapid flow of water (i.e. more ability to erode); where as a low gradient indicates a more nearly level stream bed and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riffle
A riffle is a shallow landform in a flowing channel. Colloquially, it is a shallow place in a river where water flows quickly past rocks. However, in geology a riffle has specific characteristics. Topographic, sedimentary and hydraulic indicators Riffles are almost always found to have a very low discharge compared to the flow that fills the channel (approximately 10–20%), and as a result the water moving over a riffle appears shallow and fast, with a wavy, disturbed water surface. The water's surface over a riffle at low flow also has a much steeper slope than that over other in-channel landforms. Channel sections with a mean water surface slope of roughly 0.1 to 0.5% exhibit riffles, though they can occur in steeper or gentler sloping channels with coarser or finer bed materials, respectively. Except in the period after a flood (when fresh material is deposited on a riffle), the sediment on the riverbed in a riffle is usually much coarser than on that in any other in-chan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reach (geography)
A reach is a segment of a stream, river, or arm of the sea, usually suggesting a straight, level, uninterrupted stretch. They are traditionally defined by the capabilities of sailing boats, as a stretch of a watercourse which, because it is straightish, can be sailed in one " reach" (that is, without tacking). Reaches are often named by those using the river, and a reach may be named for landmarks, natural features, and historical reasons (see, for instance, Gallions' Reach, named after the family that once owned its banks). A reach may be an expanse, or widening, of a stream or river channel. This commonly occurs after the river or stream is dammed. A reach is similar to an arm, though an arm may bend and thus have multiple reaches. The term "reach" can also refer to a level stretch, as between river rapids or locks in a canal. The word may also be used more generally to refer to any extended portion or stretch of land or water, or even metaphorically. In fluvial hydrology, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pond
A pond is a small, still, land-based body of water formed by pooling inside a depression (geology), depression, either naturally or artificiality, artificially. A pond is smaller than a lake and there are no official criteria distinguishing the two, although defining a pond to be less than in area, less than in depth and with less than 30% of its area covered by aquatic plant, emergent vegetation helps in distinguishing the ecology of ponds from those of lakes and wetlands.Clegg, J. (1986). Observer's Book of Pond Life. Frederick Warne, London Ponds can be created by a wide variety of natural processes (e.g. on floodplains as cutoff river channels, by glacial processes, by peatland formation, in coastal dune systems, by beavers). They can simply be isolated depressions (such as a Kettle (landform), kettle hole, vernal pool, Prairie Pothole Region, prairie pothole, or simply natural undulations in undrained land) filled by runoff, groundwater, or precipitation, or all three ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stagnant Water
Water stagnation occurs when water stops flowing for a long period of time. Stagnant water can be a significant environmental hazard. Dangers Malaria and dengue are among the main dangers of still water, which can become a breeding ground for the mosquitoes that transmit these diseases. Stagnant water can be dangerous because it provides a better incubator than running water for many kinds of infectious pathogens. Stagnant water can be contaminated with human and animal feces, particularly in deserts or other areas of low rainfall. Water stagnation for as little as six days can completely change bacterial community composition and increase cell count. Stagnant water may be classified into the following basic, although overlapping, types: * Water body stagnation (stagnation in swamp, lake, lagoon, river, etc.) * Surface and ground water stagnation * Trapped water stagnation. The water may be trapped in human artifacts (discarded cans, plant pots, tires, dug-outs, roo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosquito Larva
Mosquitoes, the Culicidae, are a family of small flies consisting of 3,600 species. The word ''mosquito'' (formed by '' mosca'' and diminutive ''-ito'') is Spanish and Portuguese for ''little fly''. Mosquitoes have a slender segmented body, one pair of wings, three pairs of long hair-like legs, and specialized, highly elongated, piercing-sucking mouthparts. All mosquitoes drink nectar from flowers; females of some species have in addition adapted to drink blood. The group diversified during the Cretaceous period. Evolutionary biologists view mosquitoes as micropredators, small animals that parasitise larger ones by drinking their blood without immediately killing them. Medical parasitologists view mosquitoes instead as vectors of disease, carrying protozoan parasites or bacterial or viral pathogens from one host to another. The mosquito life cycle consists of four stages: egg, larva, pupa, and adult. Eggs are laid on the water surface; they hatch into motile larvae that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
