Spring (hydrology) in the context of "Hydra, Saronic Islands"

Laayoune or El Aaiún (Arabic: العيون, al-ʕuyūn [alʕujuːn], Hassaniyya: [ˈləʕjuːn] , lit. 'The Springs') is the largest city of the disputed territory of Western Sahara, with a population of 271,344 in 2023. The city is the de jure capital of the Sahrawi Arab Democratic Republic, though it is under de facto Moroccan administration as occupied territory. The modern city is thought to have been founded by the Spanish captain Antonio de Oro in 1938. From 1958, it became the administrative capital of the Spanish Sahara, administered by the Governor General of Spanish West Africa.

In 2023, Laayoune is the capital of the Laâyoune-Sakia El Hamra region administered by Morocco, it is still under the supervision of MINURSO, a UN mission.

A stream is a continuous body of surface water flowing within the bed and banks of a 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 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), daylighted subterranean water, and surfaced groundwater (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 precipitation. The stream encompasses surface, subsurface and groundwater fluxes that respond to geological, geomorphological, hydrological and biotic controls.

A hot spring, thermal spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by circulation through faults to hot rock deep in the Earth's crust.

Hot spring water often contains large amounts of dissolved minerals. The chemistry of hot springs ranges from acid sulfate springs with a pH as low as 0.8, to alkaline chloride springs saturated with silica, to bicarbonate springs saturated with carbon dioxide and carbonate minerals. Some springs also contain abundant dissolved iron. The minerals brought to the surface in hot springs often feed communities of extremophiles, microorganisms adapted to extreme conditions, and it is possible that life on Earth had its origin in hot springs.

A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from the ocean, although they may be connected with the ocean by rivers. Lakes, like other bodies of water, are part of the water cycle, the processes by which water moves around the Earth. Most lakes are fresh water and account for almost all the world's surface freshwater, but some are salt lakes with salinities even higher than that of seawater. Lakes vary significantly in surface area and volume of water.

Lakes are typically larger and deeper than ponds, which are also water-filled basins on land, although there are no official definitions or scientific criteria distinguishing the two. Lakes are also distinct from lagoons, which are generally shallow tidal pools dammed by sandbars or other material at coastal regions of oceans or large lakes. Most lakes are fed by springs, and both fed and drained by creeks and rivers, but some lakes are endorheic without any outflow, while volcanic lakes are filled directly by precipitation runoffs and do not have any inflow streams.

A nymph (Ancient Greek: νύμφη, romanized: nýmphē; Attic Greek: [nýmpʰɛː]; sometimes spelled nymphe) is a minor female nature deity in ancient Greek folklore. Distinct from other Greek goddesses, nymphs are generally regarded as personifications of nature; they are typically tied to a specific place, landform, or tree, and are usually depicted as maidens. Because of their association with springs, they were often seen as having healing properties; other divine powers of the nymphs included divination and shapeshifting. In spite of their divine nature, they were not immortal.

Nymphs are divided into various broad subgroups based on their habitat, such as the Meliae (ash tree nymphs), the Dryads (oak tree nymphs), the Alseids (grove nymphs), the Naiads (spring nymphs), the Nereids (sea nymphs), the Oceanids (ocean nymphs), and the Oreads (mountain nymphs). Other nymphs included the Hesperides (evening nymphs), the Hyades (rain nymphs), and the Pleiades (companions of Artemis).

Salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as rock salt or halite. Salt is essential for life in general (being the source of the essential dietary minerals sodium and chlorine), and saltiness is one of the basic human tastes. Salt is one of the oldest and most ubiquitous food seasonings, and is known to uniformly improve the taste perception of food. Salting, brining, and pickling are ancient and important methods of food preservation.

Some of the earliest evidence of salt processing dates to around 6000 BC, when people living in the area of present-day Romania boiled spring water to extract salts; a salt works in China dates to approximately the same period. Salt was prized by the ancient Hebrews, Greeks, Romans, Byzantines, Hittites, Egyptians, and Indians. Salt became an important article of trade and was transported by boat across the Mediterranean Sea, along specially built salt roads, and across the Sahara on camel caravans. The scarcity and universal need for salt have led nations to go to war over it and use it to raise tax revenues, for instance triggering the El Paso Salt War which took place in El Paso in the late 1860s. Salt is used in religious ceremonies and has other cultural and traditional significance.

An aquifer is an underground layer of water-bearing material consisting of permeable or fractured rock, or of unconsolidated materials (gravel, sand, or silt). Aquifers vary greatly in their characteristics. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology. Related concepts include aquitard, a bed of low permeability along an aquifer, and aquiclude (or aquifuge), a solid and impermeable region underlying or overlying an aquifer, the pressure of which could lead to the formation of a confined aquifer. Aquifers can be classified as saturated versus unsaturated; aquifers versus aquitards; confined versus unconfined; isotropic versus anisotropic; porous, karst, or fractured; and transboundary aquifer.

Groundwater from aquifers is sustainably harvested by humans through the use of qanats leading to a well. This groundwater is mainly used for agricultral purposes but is used for other reasons such as home use, industrial use and is sometimes used as a source of renewable energy. Groundwater is a major source of fresh water for many regions, although it can present various challenges for the environment, such as overdrafting (extracting groundwater beyond the equilibrium yield of the aquifer), groundwater-related subsidence of land, and the salinization or pollution of the groundwater.

The Po (/poʊ/ POH, Italian: [ˈpɔ]) is the longest river in Italy. It flows eastward across northern Italy, starting from the Cottian Alps. The river's length is 652 km (405 mi), or 682 km (424 mi) if the Maira, a right bank tributary, is included. The headwaters of the Po are formed by a spring seeping from a stony hillside at Pian del Re, a flat place at the head of the Val Po under the northwest face of Monviso. The Po then extends along the 45th parallel north before ending at a delta projecting into the Adriatic Sea near Venice.

Draining a basin of 74,000 km (29,000 sq mi), the Po is characterized by its large discharge (several rivers over 1,000 km have a discharge inferior or equal to the Po). It is, with the Rhône and Nile, one of the three Mediterranean rivers with the largest water discharge. As a result of its characteristics, the river is subject to heavy flooding. Consequently, over half its length is controlled with embankments.