Euphrates

The Euphrates is the longest and one of the most historically important rivers of West Asia. Together with the Tigris, it is one of the two defining rivers of Mesopotamia. Originating in Turkey, the Euphrates flows through Syria and Iraq to join the Tigris in the Shatt al-Arab in Iraq, which empties into the Persian Gulf.
The Euphrates is the fifteenth-longest river in Asia and the longest in West Asia, at about, with a drainage area of that covers six countries.

Etymology

The term Euphrates derives from the Greek Euphrátēs, adapted from, itself from. The Elamite name is ultimately derived from cuneiform ???; read as Buranun in Sumerian and Purattu in Akkadian; many cuneiform signs have a Sumerian pronunciation and an Akkadian pronunciation, taken from a Sumerian word and an Akkadian word that mean the same. The Akkadian Purattu has been perpetuated in Semitic languages and in other nearby languages of the time. The Elamite, Akkadian, and possibly Sumerian forms are suggested to be from an unrecorded substrate language. Tamaz V. Gamkrelidze and Vyacheslav Ivanov suggest the proto-Sumerian *burudu "copper" as an origin, with an explanation that Euphrates was the river by which copper ore was transported in rafts, since Mesopotamia was the center of copper metallurgy during the period.
The Euphrates is called Yeprat in Armenian, Perat in modern Hebrew, Fırat in Turkish, فرات in Ottoman Turkish and Firat in Kurdish. The Mandaic name is , and is often mentioned as in Mandaean scriptures such as the Ginza Rabba. In Mandaean scriptures, the Euphrates is considered to be the earthly manifestation of the heavenly yardna or flowing river.
The earliest references to the Euphrates come from cuneiform texts found in Shuruppak and pre-Sargonic Nippur in southern Iraq and date to the mid-3rd millennium BCE. In these texts, written in Sumerian, the Euphrates is called Buranuna. The name could also be written KIB.NUN. or ^dKIB.NUN, with the prefix "^d" indicating that the river was a divinity. In Sumerian, the name of the city of Sippar in modern-day Iraq was also written UD.KIB.NUN, indicating a historically strong relationship between the city and the river.

Course

The Euphrates is the longest river of West Asia. It emerges from the confluence of the Kara Su or Western Euphrates and the Murat Su or Eastern Euphrates upstream from the town of Keban in southeastern Turkey. Daoudy and Frenken put the length of the Euphrates from the source of the Murat River to the confluence with the Tigris at, of which is in Turkey, in Syria and in Iraq. The same figures are given by Isaev and Mikhailova. The length of the Shatt al-Arab, which connects the Euphrates and the Tigris with the Persian Gulf, is given by various sources as.
Both the Kara Su and the Murat Su rise northwest from Lake Van at elevations of and amsl, respectively. At the location of the Keban Dam, the two rivers, now combined into the Euphrates, have dropped to an elevation of amsl. From Keban to the Syrian–Turkish border, the river drops another over a distance of less than. Once the Euphrates enters the Upper Mesopotamian plains, its grade drops significantly; within Syria the river falls while over the last stretch between Hīt and the Shatt al-Arab the river drops only.

Discharge

The Euphrates receives most of its water in the form of rainfall and melting snow, resulting in peak volumes during the months April through May. Discharge in these two months accounts for 36 percent of the total annual discharge of the Euphrates, or even 60–70 percent according to one source, while low runoff occurs in summer and autumn. The average natural annual flow of the Euphrates has been determined from early- and mid-twentieth century records as at Keban, at Hīt and at Hindiya. However, these averages mask the high inter-annual variability in discharge; at Birecik, just north of the Syro–Turkish border, annual discharges have been measured that ranged from a low volume of in 1961 to a high of in 1963.
The discharge regime of the Euphrates has changed dramatically since the construction of the first dams in the 1970s. Data on Euphrates discharge collected after 1990 show the impact of the construction of the numerous dams in the Euphrates and of the increased withdrawal of water for irrigation. Average discharge at Hīt after 1990 has dropped to per second. The seasonal variability has equally changed. The pre-1990 peak volume recorded at Hīt was per second, while after 1990 it is only per second. The minimum volume at Hīt remained relatively unchanged, rising from per second before 1990 to per second afterward.

Tributaries

In Syria, three rivers add their water to the Euphrates; the Sajur, the Balikh and the Khabur. These rivers rise in the foothills of the Taurus Mountains along the Syro–Turkish border and add comparatively little water to the Euphrates. The Sajur is the smallest of these tributaries; emerging from two streams near Gaziantep and draining the plain around Manbij before emptying into the reservoir of the Tishrin Dam. The Balikh receives most of its water from a karstic spring near 'Ayn al-'Arus and flows due south until it reaches the Euphrates at the city of Raqqa. In terms of length, drainage basin and discharge, the Khabur is the largest of these three. Its main karstic springs are located around Ra's al-'Ayn, from where the Khabur flows southeast past Al-Hasakah, where the river turns south and drains into the Euphrates near Busayrah. Once the Euphrates enters Iraq, there are no more natural tributaries to the Euphrates, although canals connecting the Euphrates basin with the Tigris basin exist.

Name	Length	Watershed size	Discharge	Bank
Kara Su				Confluence
Murat River				Confluence
Sajur River			4.1 m³/s	Right
Balikh River			6 m³/s	Left
Khabur River			45 m³/s	Left

Drainage basin

The drainage basins of the Kara Su and the Murat River cover an area of and, respectively. Estimates of the area of the Euphrates drainage basin vary widely; from a low to a high. Recent estimates put the basin area at, and. The greater part of the Euphrates basin is located in Turkey, Syria, and Iraq. According to both Daoudy and Frenken, Turkey's share is 28 percent, Syria's is 17 percent and that of Iraq is 40 percent. Isaev and Mikhailova estimate the percentages of the drainage basin lying within Turkey, Syria and Iraq at 33, 20 and 47 percent respectively. Some sources estimate that approximately 15 percent of the drainage basin is located within Saudi Arabia, while a small part falls inside the borders of Kuwait. Finally, some sources also include Jordan in the drainage basin of the Euphrates; a small part of the eastern desert drains toward the east rather than to the west.

Climate change

In 2021, the Iraqi Ministry of Water Resources reported that the Euphrates river could dry out by 2040 due to climate change and droughts.

Natural history

The Euphrates flows through a number of distinct vegetation zones. Although millennia-long human occupation in most parts of the Euphrates basin has significantly degraded the landscape, patches of original vegetation remain. The steady drop in annual rainfall from the sources of the Euphrates toward the Persian Gulf is a strong determinant for the vegetation that can be supported. In its upper reaches the Euphrates flows through the mountains of Southeast Turkey and their southern foothills which support a xeric woodland. Plant species in the moister parts of this zone include various oaks, pistachio trees, and Rosaceae. The drier parts of the xeric woodland zone supports less dense oak forest and Rosaceae. Here can also be found the wild variants of many cereals, including einkorn wheat, emmer, oat and rye.
South of this zone lies a zone of mixed woodland-steppe vegetation. Between Raqqa and the Syro–Iraqi border the Euphrates flows through a steppe landscape. This steppe is characterised by white wormwood and Amaranthaceae. Throughout history, this zone has been heavily overgrazed due to the practicing of sheep and goat pastoralism by its inhabitants. Southeast of the border between Syria and Iraq starts true desert. This zone supports either no vegetation at all or small pockets of Chenopodiaceae or Poa sinaica. Although today nothing of it survives due to human interference, research suggests that the Euphrates Valley would have supported a riverine forest. Species characteristic of this type of forest include the Oriental plane, the Euphrates poplar, the tamarisk, the ash and various wetland plants.
Among the fish species in the Tigris–Euphrates basin, the family of the Cyprinidae are the most common, with 34 species out of 52 in total. Among the Cyprinids, the mangar has good recreational fishing qualities, leading the British to nickname it the "Tigris salmon." The Euphrates softshell turtle is an endangered soft-shelled turtle that is limited to the Tigris–Euphrates river system.
The Neo-Assyrian palace reliefs from the 1st millennium BCE depict lion and bull hunts in fertile landscapes. Sixteenth to nineteenth century European travellers in the Syrian Euphrates basin reported on an abundance of animals living in the area, many of which have become rare or even extinct. Species like gazelle, onager and the now-extinct Arabian ostrich lived in the steppe bordering the Euphrates valley, while the valley itself was home to the wild boar. Carnivorous species include the wolf, the golden jackal, the red fox, the leopard and the lion. The Syrian brown bear can be found in the mountains of Southeast Turkey. The presence of Eurasian beaver has been attested in the bone assemblage of the prehistoric site of Tell Abu Hureyra in Syria, but the beaver has never been sighted in historical times.