Estuary
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea.Estuaries form a transition zone between river environments and maritime environments known as ecotone. Estuaries are subject both to marine influences such as tides, waves, and the influx of saline water and to riverine influences such as flows of freshwater and sediment. The mixing of seawater and freshwater provides high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world.Most existing estuaries formed during the Holocene epoch with the flooding of river-eroded or glacially scoured valleys when the sea level began to rise about 10,000–12,000 years ago. Estuaries are typically classified according to their geomorphological features or to water-circulation patterns. They can have many different names, such as bays, harbors, lagoons, inlets, or sounds, although some of these water bodies do not strictly meet the above definition of an estuary and could be fully saline.
Many estuaries suffer degeneration from a variety of factors including soil erosion, deforestation, overgrazing, overfishing and the filling of wetlands. Eutrophication may lead to excessive nutrients from sewage and animal wastes; pollutants including heavy metals, polychlorinated biphenyls, radionuclides and hydrocarbons from sewage inputs; and diking or damming for flood control or water diversion.
Estuary (noun)
Coastal water body where ocean tides and river water merge, resulting in a brackish water zone.
Estuary (noun)
An ocean inlet also fed by fresh river water.
Delta (noun)
The fourth letter of the modern Greek alphabet Δ, δ.
Delta (noun)
A landform at the mouth of a river where it empties into a body of water.
“w|Nile Delta|Nile Delta”
Delta (noun)
The letter D in the ICAO spelling alphabet, which assigns words to letters of the alphabet.
Delta (noun)
The symbol Δ.
Delta (noun)
A small but noticeable effect. Compare epsilon.
“This will slow the main code path down, but only by delta.”
Delta (noun)
The set of differences between two versions of a file.
“When you update the file, the system will only save the deltas.”
Delta (noun)
The angle subtended at the center of a circular arc.
Delta (noun)
A type of cargo bike that has one wheel in front and two in back.
Delta (noun)
The closed figure produced by connecting three coils or circuits successively, end for end, especially in a three-phase system.
“delta winding; delta connection; delta current”
Delta (noun)
The rate of change in an option value with respect to the underlying asset’s price.
Delta (noun)
A value in delta notation indicating the relative abundances of isotopes.
Delta (noun)
the fourth letter of the Greek alphabet (Δ, δ), transliterated as ‘d’.
Delta (noun)
a fourth-class mark given for an essay, examination paper, or other piece of work.
Delta (noun)
the fourth in a series of items, categories, etc.
“delta hepatitis”
Delta (noun)
the fourth (usually fourth-brightest) star in a constellation
“Delta Cephei”
Delta (noun)
a record of the differences between two versions of a file
“updates will be delivered as delta updates instead of complete application downloads”
“the diff command can be used to generate the delta between two files”
Delta (noun)
a code word representing the letter D, used in radio communication.
Delta (noun)
a triangular tract of sediment deposited at the mouth of a river, typically where it diverges into several outlets
“the Nile delta”
“a huge delta system developed”