Perennial water body usually refers to mainly liquid fresh water, as opposed to sea and glaciers or other ice. Most frequently the term refers to running water (lotic ecosystems) as in perennial streams and large rivers, but the distinction between perennial and non-perennial water is of equal importance in lentic aquatic ecosystems, those that are associated with relatively still terrestrial waters such as lakes and ponds. Simplistically a perennial water body is one that keeps full or flowing throughout the year for all or most years, but in practice there are degrees and kinds of distinction. The definition is not precise, because most water bodies vary in fullness according to the season, and according to the heaviness of precipitation and other factors during any given year. Also, the water level in many such water bodies as do not actually dry out, may nonetheless drop so drastically that their surface area is greatly reduced. They even may be split into several separate water bodies with dry land between, either arid or covered with vegetation. The internal ecology of such water may differ drastically between periods of drought and deep water. In some cases the seasonal cycle is ecologically important, whereas in other examples exceptional water levels are too rare to be taken routinely into account. There also may be effectively permanent changes; increasingly frequently even large rivers have lost their perennial status under the burden of the human demand for fresh water for purposes of agriculture, industry or the needs of the populations of large cities. The Colorado River for instance has run dry for extended periods in most years since 1960 without reaching the sea. Intermittent or ephemeral streams are those that run dry repeatedly, either seasonally or soon after rain stops. Some definitions of perennial water bodies specifically include those that only are perennial except in years of severe or unusual drought.[1]
Perennial standing (lentic) water is usually called a lake or a pond, but there are several local or dialect English words for such features. Examples include mere, tarn, loch or fen. Each has a special meaning, though modern usage tends to be loose. Vlei is a foreign example that may or may not mean a perennial body of water, but more often than not refers to a seasonal pond.
^P. Sam Lake (9 June 2011). Drought and Aquatic Ecosystems: Effects and Responses. John Wiley & Sons. pp. 32–. ISBN 978-1-4443-4179-9. Retrieved 25 April 2013.
to running water (lotic ecosystems) as in perennial streams and large rivers, but the distinction between perennial and non-perennialwater is of equal...
In botany, a perennial plant or simply perennial is a plant that lives more than two years. The term (per- + -ennial, "through the years") is often used...
Water on Mars. New York: Oxford University Press. p. 197. Bibring JP, Langevin Y, Poulet F, Gendrin A, Gondet B, Berthé M, et al. (2004). "Perennial Water...
A perennial stream is a stream that has continuous flow of surface water throughout the year in at least parts of its catchment during seasons of normal...
provided perennialwater supply is available to cater to the high rate of evapotranspiration from the cultivated land. Though the overall water resources...
Perennial crops are a perennial plant species that are cultivated and live longer than two years without the need of being replanted each year. Naturally...
and Nepal. It inhabits grassy plains and lightly forested areas with perennialwater sources. It stands up to 74 to 84 cm (29 to 33 in) high at the shoulder...
A perennial candidate is a political candidate who frequently runs for elected office and rarely, if ever, wins. Perennial candidates are most common where...
The project seeks to end the perennialwater shortages bedevilling Zimbabwe's second city of Bulawayo by bringing water from the mighty Zambezi river...
Lupinus perennis (also wild perennial lupine, wild lupine, sundial lupine, blue lupine, Indian beet, or old maid's bonnets) is a flowering plant in the...
A perennial grain is a grain crop that lives and remains productive for two or more years, rather than growing for only one season before harvest, like...
the water supply to prevent the pipeline from freezing. Below Havasupai Gardens, both Garden Creek and Pipe Creek flow year-round (perennial). Water is...
Perennial vegetables are vegetables that can live for more than two years. Some well known perennial vegetables from the temperate regions of the world...
including perennial pepperweed, broadleaved pepperweed, pepperwort, or peppergrass, dittander, dittany, and tall whitetop, is a perennial plant that...
Israelite towns on the Eastern Hill is based on the existence of only one perennialwater source in the area, the Gihon Spring, and on archaeological excavations...
Perennial rice are varieties of long-lived rice that are capable of regrowing season after season without reseeding; they are being developed by plant...
Mentha aquatica (water mint; syn. Mentha hirsuta Huds.) is a perennial flowering plant in the mint family Lamiaceae. It grows in moist places and is native...
river water-crowfoot,) is a species of buttercup. It is a perennialwater plant, which when in favourable conditions (such as fast flowing water,) can...
the Mogollon Rim. Here, water emerges at the surface at the rate of about 2,700 cubic feet (76 m3) per minute. The perennialwater supply supports one of...
BCE, and the eponymous texts may have been written c. 800 BCE. As a perennialwater source in this arid region it constituted an important station on an...
stream, a body of water must be either recurring or perennial. Recurring (intermittent) streams have water in the channel for at least part of the year. A...
River to form the Burqin River, the water velocity at the Kanas Bridge is 2.5 meters per second under the perennialwater level. 任颖 (2006). "喀纳斯河大桥方案设计"....
covers an area of 163 square kilometers. It has a number of perennialwater rivulets, water bodies and grass land. There are patches of virgin forests...
perennialwater resources. A tank is often an earthen bund (embankment or levee) constructed across a long slope to collect and store surface water from...
notable for birding as many birds overwinter there. It is a fresh waterperennialwater body that came into existence after the formation of the Upper Ganges...
and the extensive farmland which extends up to Irai water reservoir. This lake is a perennialwater source which offers a good habitat for Muggar crocodiles...
(syn. Myosotis palustris), the true forget-me-not or water forget-me-not, is a herbaceous perennial flowering plant in the borage family, Boraginaceae....
ecosystems in India. Loss of vegetation, salinization, excessive inundation, water pollution, invasive species, excessive development and road building, have...
of dissolved solids. There are three major types of surface water. Permanent (perennial) surface waters are present year round, and includes lakes, rivers...
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