The Euphrates (i/juːˈfreɪtiːz/; Arabic: الفرات: al-Furāt, Hebrew: פרת: Prat, Turkish: Fırat, Kurdish: Firat) is the longest and one of the most historically important rivers of Western Asia. Together with the Tigris, it is one of the two defining rivers of Mesopotamia. Originating in eastern Turkey, the Euphrates flows through Syria and Iraq to join the Tigris in the Shatt al-Arab, which empties into the Persian Gulf.
The Ancient Greek form Euphrátēs (Ancient Greek: Ευφράτης) was borrowed from Old Persian Ufrātu, itself from Elamite ú-ip-ra-tu-iš. In Akkadian the river was similarly called Purattu, which has been perpetuated in Semitic languages (cf. Syriac P(ə)rāṯ, Arabic al-Furrāt) and in other nearby languages of the time (cf. Hurrian Puranti, Sabarian Uruttu). The Elamite, Akkadian, and possibly Sumerian forms are from an unrecorded substrate language. 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 (logographic: UD.KIB.NUN). The name could also be written KIB.NUN.(NA) 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 a written UD.KIB.NUN, indicating a historically strong relationship between the city and the river.
The Euphrates is the longest river of Western Asia. It emerges from the confluence of the Kara Su or Western Euphrates (450 kilometres (280 mi)) and the Murat Su or Eastern Euphrates (650 kilometres (400 mi)) 10 kilometres (6.2 mi) 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 3,000 kilometres (1,900 mi), of which 1,230 kilometres (760 mi) falls in Turkey, 710 kilometres (440 mi) in Syria and 1,060 kilometres (660 mi) 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 145–195 kilometres (90–121 mi). Both the Kara Su and the Murat Su rise northwest from Lake Van at elevations of 3,290 metres (10,790 ft) and 3,520 metres (11,550 ft) amsl, respectively. At the location of the Keban Dam, the two rivers, now combined into the Euphrates, have dropped to an elevation of 693 metres (2,274 ft) amsl. From Keban to the Syrian–Turkish border, the river drops another 368 metres (1,207 ft) over a distance of less than 600 kilometres (370 mi). Once the Euphrates enters the Upper Mesopotamian plains, its grade drops significantly; within Syria the river falls 163 metres (535 ft) while over the last stretch between Hīt and the Shatt al-Arab the river drops only 55 metres (180 ft).
Discharge of the EuphratesEdit
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 20.9 cubic kilometres (5.0 cu mi) at Keban, 36.6 cubic kilometres (8.8 cu mi) at Hīt and 21.5 cubic kilometres (5.2 cu mi) at Hindiya. However, these averages mask the high inter-annual variability in discharge; at Birecik, just above the Syro–Turkish border, annual discharges have been measured that ranged from a low volume of 15.3 cubic kilometres (3.7 cu mi) in 1961 to a high 42.7 cubic kilometres (10.2 cu mi) 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 356 cubic metres (12,600 cu ft) per second (11.2 cubic kilometres (2.7 cu mi) per year). The seasonal variability has equally changed. The pre-1990 peak volume recorded at Hīt was 7,510 cubic metres (265,000 cu ft) per second, while after 1990 it is only 2,514 cubic metres (88,800 cu ft) per second. The minimum volume at Hīt remained relatively unchanged, rising from 55 cubic metres (1,900 cu ft) per second before 1990 to 58 cubic metres (2,000 cu ft) per second afterward.
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 Ar-Raqqah. 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.
The drainage basins of the Kara Su and the Murat River cover an area of 22,000 square kilometres (8,500 sq mi) and 40,000 square kilometres (15,000 sq mi), respectively. The estimates that have been made for the area of the Euphrates drainage basin vary widely; from a low 233,000 square kilometres (90,000 sq mi) to a high 766,000 square kilometres (296,000 sq mi). Recent estimates put the basin area at 388,000 square kilometres (150,000 sq mi), 444,000 square kilometres (171,000 sq mi) and 579,314 square kilometres (223,674 sq mi). 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 (220 square kilometres (85 sq mi)) drains toward the east rather than to the west.
Palaeolithic to Chalcolithic periodsEdit
The early occupation of the Euphrates basin was limited to its upper reaches; that is, the area that is popularly known as the Fertile Crescent. Acheulean stone artifacts have been found in the Sajur basin and in the El Kowm oasis in the central Syrian steppe; the latter together with remains of Homo erectus that were dated to 450,000 years old. In the Taurus Mountains and the upper part of the Syrian Euphrates valley, early permanent villages such as Abu Hureyra – at first occupied by hunter-gatherers but later by some of the earliest farmers, Jerf el-Ahmar, Mureybet and Nevalı Çori became established from the eleventh millennium BCE onward. In the absence of irrigation, these early farming communities were limited to areas where rainfed agriculture was possible, that is, the upper parts of the Syrian Euphrates as well as Turkey. Late Neolithic villages, characterized by the introduction of pottery in the early 7th millennium BCE, are known throughout this area. Occupation of lower Mesopotamia started in the 6th millennium and is generally associated with the introduction of irrigation, as rainfall in this area is insufficient for dry agriculture. Evidence for irrigation has been found at several sites dating to this period, including Tell es-Sawwan. During the 5th millennium BCE, or late Ubaid period, northeastern Syria was dotted by small villages, although some of them grew to a size of over 10 hectares (25 acres). In Iraq, sites like Eridu and Ur were already occupied during the Ubaid period. Clay boat models found at Tell Mashnaqa along the Khabur indicate that riverine transport was already practiced during this period. The Uruk period, roughly coinciding with the 4th millennium BCE, saw the emergence of truly urban settlements across Mesopotamia. Cities like Tell Brak and Uruk grew to over 100 hectares (250 acres) in size and displayed monumental architecture. The spread of southern Mesopotamian pottery, architecture and sealings far into Turkey and Iran has generally been interpreted as the material reflection of a widespread trade system aimed at providing the Mesopotamian cities with raw materials. Habuba Kabira on the Syrian Euphrates is a prominent example of a settlement that is interpreted as an Uruk colony.
During the Jemdet Nasr and Early Dynastic periods (3100–2350 BCE), southern Mesopotamia experienced a growth in the number and size of settlements, suggesting strong population growth. These settlements, including sites like Sippar, Uruk and Kish, were organized in competing city-states. Many of these cities were located along canals of the Euphrates and the Tigris that have since dried up, but that can still be identified from remote sensing imagery. A similar development took place in Upper Mesopotamia, although only in the second part of the 3rd millennium and on a smaller scale than in Lower Mesopotamia. Sites like Mari and Tell Leilan grew to prominence for the first time during this period. Large parts of the Euphrates basin were for the first time united under a single ruler during the Akkadian and Ur III empires, which controlled – either directly or indirectly through vassals – large parts of modern-day Iraq and northeastern Syria. Following their collapse, Mari asserted its power over northeast Syria while southern Mesopotamia was controlled by city-states like Isin and Larsa before their territories were absorbed by Babylon under Hammurabi in the 18th century BCE. In the second half of the 2nd millennium BCE, the Euphrates basin was divided between Kassite Babylon in the south and Mitanni in the north, with the latter being eventually replaced by Assyria and the Hittite Empire. Following the collapse of the Hittite Empire and the reduction in power of Assyria and Babylonia during the 12th century BCE, struggles broke out between Babylonia and Assyria over the control of the Iraqi Euphrates basin. The Neo-Assyrian Empire eventually emerged victorious out of this conflict and also succeeded in gaining control of the northern Euphrates basin in the first half of the 1st millennium BCE. In the centuries to come, control of the wider Euphrates basin shifted from the Neo-Assyrian Empire to the Neo-Babylonian Empire in the 7th century and to the Achaemenids in the 6th century BCE. The Achaemenid Empire was in turn overrun by Alexander the Great, who defeated the last king Darius III and died in Babylon in 323 BCE. For several centuries, the river formed the eastern limit of effective Egyptian and Roman control and western regions of the Persian Empire.
After World War I, the borders in Southwest Asia were redrawn in the Treaty of Lausanne, when the Ottoman Empire was partitioned. Clause 109 of the treaty stipulated that the three riparian states of the Euphrates (at that time Turkey, France for its Syrian mandate and the United Kingdom for its mandate of Iraq) had to reach a mutual agreement on the use of its water and on the construction of any hydraulic installation. An agreement between Turkey and Iraq signed in 1946 required Turkey to report to Iraq on any hydraulic changes it made on the Tigris–Euphrates river system, and allowed Iraq to construct dams on Turkish territory to manage the flow of the Euphrates.
Turkey and Syria completed their first dams on the Euphrates – the Keban Dam and the Tabqa Dam, respectively – within one year of each other and filling of the reservoirs commenced in 1975. At the same time, the area was hit by severe drought and river flow toward Iraq was reduced from 15.3 cubic kilometres (3.7 cu mi) in 1973 to 9.4 cubic kilometres (2.3 cu mi) in 1975. This led to an international crisis during which Iraq threatened to bomb the Tabqa Dam. An agreement was eventually reached between Syria and Iraq after intervention by Saudi Arabia and the Soviet Union. A similar crisis, although not escalating to the point of military threats, occurred in 1981 when the Keban Dam reservoir had to be refilled after it had been almost emptied to temporarily increase Turkey's hydroelectricity production. In 1984, Turkey unilaterally declared that it would ensure a flow of at least 500 cubic metres (18,000 cu ft) per second, or 16 cubic kilometres (3.8 cu mi) per year, into Syria, and in 1987 a bilateral treaty to that effect was signed between the two countries. Another bilateral agreement from 1989 between Syria and Iraq settles the amount of water flowing into Iraq at 60 percent of the amount that Syria receives from Turkey. In 2008, Turkey, Syria and Iraq instigated the Joint Trilateral Committee (JTC) on the management of the water in the Tigris–Euphrates basin and on 3 September 2009 a further agreement was signed to this effect.