An endorheic lake (also called a sink lake or terminal lake) is a collection of water within an endorheic basin, or sink, with no evident outlet. [1] Endorheic lakes are generally saline as a result of being unable to get rid of solutes left in the lake by evaporation. [2] These lakes can be used as indicators of anthropogenic change, such as irrigation or climate change, in the areas surrounding them. Lakes with subsurface drainage are considered cryptorheic.
The two main ways that endorheic lakes accumulate water are through river flow into the lake (discharge) and precipitation falling into the lake. [2] The collected water of the lake, instead of discharging, can only be lost due to either evapotranspiration or percolation (water sinking underground, e.g., to become groundwater in an aquifer). Because of this lack of an outlet, endorheic lakes are mostly salt water rather than fresh water. The salinity in the lake gradually builds up through years as water evaporates and leaves its solutes behind.[ citation needed ]
Depending on water losses, precipitation, and inflow (e.g., a spring, a tributary, or flooding), the temporal result of a lake in a sink may change. The lake could be a persistent lake, an intermittent lake, a playa lake (temporarily covered with water), or an ephemeral lake, which completely disappears (e. g. by evaporation) before reappearing in wetter seasons. [3] These terms (playa, ephemeral lake, etc.) are sometimes used interchangeably, but there has been activity tending towards defining meanings for each term. [4] This change would mean less confusion over the designations of different types of endorheic lakes.
Many endorheic lakes exist in arid or semi-arid climates. [5] Because these climates have limited rainfall, but also a high possibility of evaporation, endorheic lakes in these regions often experience flux in their water levels. This flux can be aggravated by anthropogenic intrusions (e.g. global warming).
In Central Asia, a large percentage of water for farming comes from surface water, like endorheic lakes, rather than precipitation. [2] Because of the overall lack of precipitation, farming in this area can only be sustained by irrigation. Massive amounts of irrigation in agrarian Central Asia have led to the reduction in size of endorheic lakes. The Aral Sea was once the second largest endorheic lake in the world, but anthropogenic effects such as bad irrigation practices have led to this lake's drastic decrease in size and turn into a desert named the Aralkum Desert.[ citation needed ]
Endorheic lakes, because of the closed nature of their systems, are sensitive to new conditions. [2] Records of previous environmental change are preserved in lake sediments in endorheic lakes that are being affected by climate change; these natural records can give information about past climates and conditions of the lake. Research on these lake sediments could lead to these lakes becoming archives of the effects of climate change. There is early evidence that in regions affected by irrigation the majority of endorheic lake area may have already been lost. [6]
Kazakhstan is located in Central Asia, with a small portion in Eastern Europe. With an area of about 2,724,900 square kilometers (1,052,100 sq mi) Kazakhstan is more than twice the combined size of the other four Central Asian states and 60% larger than Alaska. The country borders Turkmenistan, Uzbekistan, and Kyrgyzstan to the south; Russia to the north; Russia and the Caspian Sea to the west; and China's Xinjiang Uygur Autonomous Region to the east.
Turkmenistan is a landlocked country in Central Asia, bordering the Caspian Sea to the west, Iran and Afghanistan to the south, Uzbekistan to the north-east, and Kazakhstan to the north-west. It is the southernmost republic of the Commonwealth of Independent States (CIS), the loose federation created at the end of 1991 by most of the Post-Soviet states.
Uzbekistan is a country in Central Asia, located north of Turkmenistan and Afghanistan. With an area of approximately 447,000 square kilometers, Uzbekistan stretches 1,425 km (885 mi) from west to east and 930 km (580 mi) from north to south. It borders Turkmenistan to the southwest, Kazakhstan to the north and Tajikistan and Kyrgyzstan to the south and east. Uzbekistan also has four small exclaves in Turkmenistan.
The Aral Sea was an endorheic lake lying between Kazakhstan to its north and Uzbekistan to its south, which began shrinking in the 1960s and largely dried up by the 2010s. It was in the Aktobe and Kyzylorda regions of Kazakhstan and the Karakalpakstan autonomous region of Uzbekistan. The name roughly translates from Mongolic and Turkic languages to "Sea of Islands", a reference to the large number of islands that once dotted its waters. The Aral Sea drainage basin encompasses Uzbekistan and parts of Afghanistan, Iran, Kazakhstan, Kyrgyzstan, Tajikistan, and Turkmenistan.
An evaporite is a water-soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as ocean deposits, and non-marine, which are found in standing bodies of water such as lakes. Evaporites are considered sedimentary rocks and are formed by chemical sediments.
A drainage basin is an area of land in which all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the drainage divide, made up of a succession of elevated features, such as ridges and hills. A basin may consist of smaller basins that merge at river confluences, forming a hierarchical pattern.
An endorheic basin is a drainage basin that normally retains water and allows no outflow to other, external bodies of water ; instead, the water drainage flows into permanent and seasonal lakes and swamps that equilibrate through evaporation. Endorheic basins are also called closed basins, terminal basins, and internal drainage systems.
The Great Basin Desert is part of the Great Basin between the Sierra Nevada and the Wasatch Range. The desert is a geographical region that largely overlaps the Great Basin shrub steppe defined by the World Wildlife Fund, and the Central Basin and Range ecoregion defined by the U.S. Environmental Protection Agency and United States Geological Survey. It is a temperate desert with hot, dry summers and snowy winters. The desert spans large portions of Nevada and Utah, and extends into eastern California. The desert is one of the four biologically defined deserts in North America, in addition to the Mojave, Sonoran, and Chihuahuan Deserts.
A dry lake bed, also known as a playa, is a basin or depression that formerly contained a standing surface water body, which disappears when evaporation processes exceed recharge. If the floor of a dry lake is covered by deposits of alkaline compounds, it is known as an alkali flat. If covered with salt, it is known as a salt flat.
Lake Lahontan was a large endorheic prehistoric lake during the Pleistocene that occupied modern northwestern Nevada and extended into northeastern California and southern Oregon. The area of the former lake is a large portion of the Great Basin that borders the Sacramento River watershed to the west.
The Lake Eyre basin is a drainage basin that covers just under one-sixth of all Australia. It is the largest endorheic basin in Australia and amongst the largest in the world, covering about 1,200,000 square kilometres (463,323 sq mi), including much of inland Queensland, large portions of South Australia and the Northern Territory, and a part of western New South Wales. The basin is also one of the largest, least-developed arid zone basins with a high degree of variability anywhere. It supports only about 60,000 people and has no major irrigation, diversions or flood-plain developments. Low density grazing that sustains a large amount of wildlife is the major land use, occupying 82% of the total land within the basin. The Lake Eyre basin of precipitation to a great extent geographically overlaps the Great Artesian Basin underneath.
A salt lake or saline lake is a landlocked body of water that has a concentration of salts and other dissolved minerals significantly higher than most lakes. In some cases, salt lakes have a higher concentration of salt than sea water; such lakes can also be termed hypersaline lakes, and may also be pink lakes on account of their colour. An alkalic salt lake that has a high content of carbonate is sometimes termed a soda lake.
Lake Hāmūn, or the Hamoun Oasis, is a seasonal lake and wetlands in the endorheic Sīstān Basin in the Sistan region on the Afghanistan–Iran border. In Iran, it is also known as Hāmūn-e Helmand, Hāmūn-e Hīrmand, or Daryāche-ye Sīstān.
The Aydar Lake is part of the man-made Aydar-Arnasay system of lakes, which covers 4,000 square kilometres (1,500 mi2). This has 3 brackish water lakes, deep basins of the south-eastern Kyzyl Kum. The lakes are expansive reservoirs of Soviet planning.
Open and closed lakes refer to the major subdivisions of lakes – bodies of water surrounded by land. Exorheic, or open, lakes drain into a river or other body of water that ultimately drains into the ocean. Endorheic basins fall into the category of endorheic or closed lakes, wherein waters do not drain into the ocean, but are reduced by evaporation, and/or drain into the ground.
The Sistan Basin is an inland endorheic basin encompassing large parts of southwestern Afghanistan and minor parts of southeastern Iran. It is one of the driest regions in the world and an area subject to prolonged droughts. Its watershed is a system of rivers flowing from the highlands of Afghanistan into freshwater lakes and marshes and then to its ultimate destination: Afghanistan's saline Godzareh Depression, part of the extensive Sistan terminal basin. The Helmand River drains the basin's largest watershed, fed mainly by snowmelt from the mountains of Hindu Kush, but other rivers contribute also.
A lake is an often 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. Most lakes are freshwater 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.
The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake and sometimes referred to as a full-fledged sea. An endorheic basin, it lies between Europe and Asia: east of the Caucasus, west of the broad steppe of Central Asia, south of the fertile plains of Southern Russia in Eastern Europe, and north of the mountainous Iranian Plateau. It covers a surface area of 371,000 km2 (143,000 sq mi), an area approximately equal to that of Japan, with a volume of 78,200 km3 (19,000 cu mi). It has a salinity of approximately 1.2%, about a third of the salinity of average seawater. It is bounded by Kazakhstan to the northeast, Russia to the northwest, Azerbaijan to the southwest, Iran to the south, and Turkmenistan to the southeast.
Hamun-e Jaz Murian is an inland basin or depression in southeast Iran, straddling the provinces of Kerman and Sistan-Baluchistan. The area of Hamoon and Jazmourian basin stretches to 69,600 square kilometers, with the western part of 35,600 square kilometers in Kerman province and the eastern part of 34,000 square kilometers in Sistan-Baluchestan province.