TIGRIS-EUPHRATES RIVER SYSTEM

The Tigris and Euphrates river basin and its drainage network. great river system of Southwest Asia, comprising the Tigris and Euphrates rivers, which have their sources within 50 miles (80 kilometres) of each other in eastern Turkey and travel in a southeasterly direction through northern Syria and Iraq to the head of the Persian Gulf. The lower portion of the region that they define, known as Mesopotamia (Greek: Land Between the Rivers), was one of the cradles of civilization. The total length of the Euphrates (Sumerian: Buranun; Akkadian: Purattu; biblical: Perath; Arabic: Furat; Turkish: Firat) is about 1,740 miles (2,800 kilometres). The total length of the Tigris (Sumerian: Idigna; Akkadian: Idiklat; biblical: Hiddekel; Arabic: Dijlah; Turkish: Dicle) is about 1,180 miles (1,890 kilometres). The rivers usually are discussed in three parts: their upper courses, restricted to the valleys and gorges of eastern Anatolia, at elevations diminishing from those of their sources at 6,000 to 10,000 feet (1,830 to 3,050 metres) above sea level; their middle courses, in the uplands of northern Syria and Iraq, at elevations varying from 1,200 feet at the foot of the so-called Kurdish Escarpment to 170 feet at the head of the delta; and the alluvial plain, which has been created jointly by the two rivers. At Al-Qurnah the rivers join to form the Shatt al-'Arab. Additional reading The Tigris is most often written about in conjunction with the Euphrates. Broad surveys of the territories affected by these two rivers include Great Britain, Naval Intelligence Division, Iraq and the Persian Gulf (1944), a geographic handbook; George Babcock Cressey, Crossroads: Land and Life in Southwest Asia (1960); and Robert M. Adams, Heartland of Cities: Surveys of Ancient Settlement and Land Use on the Central Floodplain of the Euphrates (1981). McGuire Gibson, The City and Area of Kish (1972), discusses the river systems in relation to one area of southern Iraq. M.G. Ionides, The Rgime of the Rivers Euphrates and Tigris (1937), is still a valuable pioneering hydrologic survey. Thorkild Jacobsen and Robert M. Adams, Salt and Silt in Ancient Mesopotamian Agriculture, in Donald R. Coates (ed.), Environmental Geomorphology and Landscape Conservation, vol. 1 (1972), pp. 138145, is an important article relating the historical pattern of civilization collapse to ecological factors. G.M. Lees and N.L. Falcon, The Geographical History of the Mesopotamian Plains, Geographical Journal, 118:2439 (1952), presents a classic formulation, which has still not been disproved, on the equilibrium between infilling of the delta and the subsidence of the basin. C.E. Larsen, The Mesopotamian Delta Region: A Reconsideration of Lees and Falcon, Journal of the American Oriental Society, 95:4357 (January 1975), questions the Lees and Falcon theory. A later reformulation of the article after criticisms is C.E. Larsen and G. Evans, The Holocene Geological History of the Tigris-Euphrates-Karun Delta, in William C. Brice (ed.), The Environmental History of the Near and Middle East Since the Last Ice Age (1978), pp. 227244. In the same collection, C. Vita-Finzi, Recent Alluvian History in the Catchment of the Arabo-Persian Gulf, pp. 255261, presents a contrasting view on the formation of the delta. McGuire Gibson