Chott Melrhir
Encyclopedia
Chott
Melrhir also known as Chott Melghir or Chott Melhir is an endorheic
salt lake in northeastern Algeria
. It the westernmost part of a series of depressions
, which extend from the Gulf of Gabès
into the Sahara
. They were created between Miocene
and Early Pleistocene
as a result of compression accompanying the formation of the Atlas Mountains
. With the maximum area of about 6700 km² (2,586.9 sq mi), Chott Melrhir is the largest lake in Algeria. It lies almost entirely below the sea level, and the lowest point of Algeria, at –40 meters (131 ft), is located near the middle of the lake. Its size varies over the year and is usually larger than 130 km (80.8 mi) from east to west. The nearby cities are Biskra
(60 km north-east), El Oued
and Touggourt
(85 km south).
(periodically drying rivers), mostly from north and north-west. The largest of them are the Djedi
and Arab running from west to east down the slopes of Aurès Mountains
. Others include Abiod
, Beggour Mitta, Biskra
, Bir Az Atrous, Cheria, Demmed, Dermoun, Derradj, Djedeida, Djemorah, Halail, Horchane, Ittel, Mechra, Melh, Mzi, Messad, Oum El Ksob, Soukies, Tadmit and Zeribet. In summer, the lake and most the rivers feeding it dry out, and Chott Melrhir turns into a salt pan
. The annual water evaporation varies between 9.6 and 20 km3, and evaporation from soil nearby the lake can reach 14 km3.
Chott Melrhir is separated from the nearby Chott Meorouane, which lies south-west, by a stripe of permanently dry land which can be as narrow as 4 kilometers in some places. The bottom of the lake is mostly composed of gypsum
and mud and is covered in salt in summer. The lake emits a garlic-like odor. Although the dry soil in and around the lake appears arable, it is nearly barren due to the high concentration of salt. For the same reason, the soil absorbs much condensation overnight that keeps it partly humid during much of the day.
The climate in the Chott Melrhir is hot and arid with high evaporation and low precipitation. The average lowest and highest temperatures are 11.4 and 34.2°C, respectively, and the minimum temperature is about 0 °C. Annual precipitation is below 160 mm. The winds have a speed between 2.7 and 5.3 m/s and are mostly directed south-east between June and September and north-west between autumn and early spring. Sandstorms
are more frequent in winter and late summer and last 39 days per year on average.
), Sea Lavender (Limonium), rushes (Juncus
), glasswort (Salicornia), Sarcocornia
, bulrush (Scirpus
) and seepweeds (Suaeda
). Some species are unique for Algeria and 14 are endemic, such as Fagonia microphylla, Oudneya africana, Zygophyllum cornutum, Limoniastrum feii and Ammosperma cinerea. They grown up to 30 cm in height and host relatively rich avifauna, mostly ducks
, sandgrouse
, Houbara Bustard
(Chlamydotis undulata) and Greater Flamingo
(Phoenicopterus roseus). Lake waters are saturated with salt with concentrations reaching 0.4 kg/L and sustain only few animal species, such as brine shrimp
. Wild boars, golden jackal
s, hares and foxes were observed around the lake. In June 2003, Chott Melrhir was included to the List of Ramsar wetlands of international importance.
Chott
In geology, chott or shebka is a dry lake in the Saharan area of Africa that stays dry in the summer, but receives some water in the winter...
Melrhir also known as Chott Melghir or Chott Melhir is an endorheic
Endorheic
An endorheic basin is a closed drainage basin that retains water and allows no outflow to other bodies of water such as rivers or oceans...
salt lake in northeastern Algeria
Algeria
Algeria , officially the People's Democratic Republic of Algeria , also formally referred to as the Democratic and Popular Republic of Algeria, is a country in the Maghreb region of Northwest Africa with Algiers as its capital.In terms of land area, it is the largest country in Africa and the Arab...
. It the westernmost part of a series of depressions
Depression (geology)
A depression in geology is a landform sunken or depressed below the surrounding area. Depressions may be formed by various mechanisms.Structural or tectonic related:...
, which extend from the Gulf of Gabès
Gulf of Gabès
The Gulf of Gabès is a gulf on Tunisia's east coast in the Mediterranean Sea, off North Africa. The gulf roughly spans the coast from modern day the town of Mahrès in Sfax Gouvernorate to Djerba...
into the Sahara
Sahara
The Sahara is the world's second largest desert, after Antarctica. At over , it covers most of Northern Africa, making it almost as large as Europe or the United States. The Sahara stretches from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean...
. They were created between Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
and Early Pleistocene
Early Pleistocene
Calabrian is a subdivision of the Pleistocene Epoch of the Geologic time scale. ~1.8 Ma.—781,000 years ago ± 5,000 years, a period of ~.The end of the stage is defined by the last magnetic pole reversal and plunge in to an ice age and global drying possibly colder and drier than the late Miocene ...
as a result of compression accompanying the formation of the Atlas Mountains
Atlas Mountains
The Atlas Mountains is a mountain range across a northern stretch of Africa extending about through Morocco, Algeria, and Tunisia. The highest peak is Toubkal, with an elevation of in southwestern Morocco. The Atlas ranges separate the Mediterranean and Atlantic coastlines from the Sahara Desert...
. With the maximum area of about 6700 km² (2,586.9 sq mi), Chott Melrhir is the largest lake in Algeria. It lies almost entirely below the sea level, and the lowest point of Algeria, at –40 meters (131 ft), is located near the middle of the lake. Its size varies over the year and is usually larger than 130 km (80.8 mi) from east to west. The nearby cities are Biskra
Biskra
Biskra is the capital city of Biskra province, Algeria. In 2007, its population was recorded as 207,987.During Roman times the town was called Vescera, though this may have been simply a Latin transliteration of the native name. Around 200 AD under Septimius Severus' reign, it was seized by the...
(60 km north-east), El Oued
El Oued
El Oued or Oued Souf is a city in El Oued province, Algeria.. The oasis town is watered by an underground river, hence its name, which enables date palm cultivation and the rare use of brick construction for housing...
and Touggourt
Touggourt
Touggourt is a city in Ouargla Province, Algeria, built around an oasis in the Sahara. It is notable for its date trees. It was formerly surrounded by a moat, which the French filled up. The surrounding oasis is very fertile. From Touggourt a road 61 miles long leads across the desert north-east...
(85 km south).
Hydrology, geology and geography
During the rain season in winter, the lake is filled by numerous wadiWadi
Wadi is the Arabic term traditionally referring to a valley. In some cases, it may refer to a dry riverbed that contains water only during times of heavy rain or simply an intermittent stream.-Variant names:...
(periodically drying rivers), mostly from north and north-west. The largest of them are the Djedi
Djedi River
Djedi River or Djeddi River is a wadi in Algeria and one of the largest rivers of Sahara. It starts in the Saharan Atlas mountains, at elevation of about , flows for about approximately from west to east, and discharges into Chott Melrhir lake at about – below mean sea level, which is the lowest...
and Arab running from west to east down the slopes of Aurès Mountains
Aurès Mountains
The Aurès , or Aurea, refers to an Amazigh language-speaking region in East Algeria, as well as an extension of the Atlas mountain range that lies to the east of the Saharan Atlas in eastern Algeria and northwestern Tunisia...
. Others include Abiod
Abiod Valley
The Abiod Valley, aka Oued El Abiod, is a mountain pass in the Aurés massif, located in the Saharan Atlas in northeastern Algeria. It is included in the Readers Digest publication Natural Wonders of the World.-Geography:...
, Beggour Mitta, Biskra
Biskra Province
Biskra is a province of Algeria. The capital city is Biskra. Tolga is one of the famous daïras of this wilaya. Other localities include Lichoua, Sidi Okba, Sidi Khaled, El-Kantara and Ouled Djellal.- Administrative division :...
, Bir Az Atrous, Cheria, Demmed, Dermoun, Derradj, Djedeida, Djemorah, Halail, Horchane, Ittel, Mechra, Melh, Mzi, Messad, Oum El Ksob, Soukies, Tadmit and Zeribet. In summer, the lake and most the rivers feeding it dry out, and Chott Melrhir turns into a salt pan
Dry lake
Dry lakes are ephemeral lakebeds, or a remnant of an endorheic lake. Such flats consist of fine-grained sediments infused with alkali salts. Dry lakes are also referred to as alkali flats, sabkhas, playas or mud flats...
. The annual water evaporation varies between 9.6 and 20 km3, and evaporation from soil nearby the lake can reach 14 km3.
Chott Melrhir is separated from the nearby Chott Meorouane, which lies south-west, by a stripe of permanently dry land which can be as narrow as 4 kilometers in some places. The bottom of the lake is mostly composed of gypsum
Gypsum
Gypsum is a very soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is found in alabaster, a decorative stone used in Ancient Egypt. It is the second softest mineral on the Mohs Hardness Scale...
and mud and is covered in salt in summer. The lake emits a garlic-like odor. Although the dry soil in and around the lake appears arable, it is nearly barren due to the high concentration of salt. For the same reason, the soil absorbs much condensation overnight that keeps it partly humid during much of the day.
Climate
Dust storm
A dust / sand storm is a meteorological phenomenon common in arid and semi-arid regions. Dust storms arise when a gust front or other strong wind blows loose sand and dirt from a dry surface. Particles are transported by saltation and suspension, causing soil to move from one place and deposition...
are more frequent in winter and late summer and last 39 days per year on average.
Flora and fauna
The shallow waters of the lake contain scarce vegetation composed of 72 species of plants which have adapted to salty water, such as Parish's glasswort (Arthrocnemum subterminaleArthrocnemum subterminale
Arthrocnemum subterminale is a species of flowering plant in the amaranth family known by the common name Parish's glasswort. It is native to California and the northern states of Mexico, where it grows in coastal and inland salt marshes, alkali flats, and other habitat with saline soils...
), Sea Lavender (Limonium), rushes (Juncus
Juncus
Juncus is a genus in the plant family Juncaceae. It consists of some 200 to 300 or more species of grassy plants commonly called rushes...
), glasswort (Salicornia), Sarcocornia
Sarcocornia
Sarcocornia is a genus of succulent salt tolerant coastal plants.-Species:*S. alpini*S. blackiana *S. fruticosa*Sarcocornia globosa...
, bulrush (Scirpus
Scirpus
The plant genus Scirpus consists of a large number of aquatic, grass-like species in the family Cyperaceae , many with the common names club-rush or bulrush . Other common names are deergrass or grassweed.The genus has a cosmopolitan distribution, and grows in wetlands and moist soil...
) and seepweeds (Suaeda
Suaeda
Suaeda is a genus of plants also known as seepweeds and seablites. Most species are confined to saline or alkaline soil habitats, such as coastal salt-flats and tidal wetlands. Many species have thick, succulent leaves, a characteristic seen in various plant genera that thrive in salty habitats...
). Some species are unique for Algeria and 14 are endemic, such as Fagonia microphylla, Oudneya africana, Zygophyllum cornutum, Limoniastrum feii and Ammosperma cinerea. They grown up to 30 cm in height and host relatively rich avifauna, mostly ducks
Anas
Anas is a genus of dabbling ducks. It includes mallards, wigeons, teals, pintails and shovelers in a number of subgenera. Some authorities prefer to elevate the subgenera to genus rank...
, sandgrouse
Sandgrouse
The sandgrouse are a family, Pteroclididae, of 16 bird species, the only living members of the order Pteroclidiformes. They are restricted to treeless open country in the Old World, such as plains and semi-deserts. They are distributed across northern, southern and eastern Africa as well as...
, Houbara Bustard
Houbara Bustard
The Houbara Bustard, Chlamydotis undulata, is a large bird in the bustard family.-Description:The Houbara Bustard is a small to mid-sized bustard. It measures in length and spans across the wings. It is brown above and white below, with a black stripe down the sides of its neck. In flight, the...
(Chlamydotis undulata) and Greater Flamingo
Greater Flamingo
The Greater Flamingo is the most widespread species of the flamingo family. It is found in parts of Africa, southern Asia , and southern Europe...
(Phoenicopterus roseus). Lake waters are saturated with salt with concentrations reaching 0.4 kg/L and sustain only few animal species, such as brine shrimp
Brine shrimp
Artemia is a genus of aquatic crustaceans known as brine shrimp. Artemia, the only genus in the family Artemiidae, has changed little externally since the Triassic period...
. Wild boars, golden jackal
Golden Jackal
The golden jackal , also known as the common jackal, Asiatic jackal, thos or gold-wolf is a Canid of the genus Canis indigenous to north and northeastern Africa, southeastern and central Europe , Asia Minor, the Middle East and southeast Asia...
s, hares and foxes were observed around the lake. In June 2003, Chott Melrhir was included to the List of Ramsar wetlands of international importance.