Douro (redirected from Rio Duero)

Douro (Port. dō`r) or Duero (Span. dā`rō), river, c.475 mi (765 km) long, rising in the Sierra de Urbión, N central Spain. It flows W across N Spain, then southwest to form part of the Spanish-Portuguese border before flowing W across N Portugal to the Atlantic Ocean at Pôrto. One of the longest rivers of the Iberian Peninsula, it drains most of the northern portion of the central plateau; the Tormes, Esla, and Pisuerga rivers are its chief tributaries. Silting, rapids, and deep gorges combine to make the Douro unnavigable. The middle Douro is extensively used for irrigation. Several hydroelectric power plants are along the river, and through an international agreement the power is used for irrigation and development. Grapes are the chief crop of the Douro valley, and the Douro estuary is the center of Portuguese wine trade.

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Douro 

(Duero), a river on the Iberian peninsula, with a length of 925 km (or, according to other sources, 938 km). The area of the river basin is 95,000 sq km.

The river originates in the Iberian Mountains in Spain, and in its upper and middle reaches flows through a deep valley and crosses the Old Castillian Plateau. Descending from the plateau, the Douro flows 110 km through one of Europe’s most splendid canyons, which is 200-500 m deep. The width of the river bed ranges from 30 to 40 m. Lower, in Portuguese territory, the Douro flows at first through a wide valley in mountainous and hilly areas, then through maritime lowlands, and finally into the Atlantic Ocean. The mouth of the Douro is an estuary, shallowed by a sandbar. Its main tributaries are the Pisuerga, Adaja, Esla, Tormes, and Támega. In winter and spring there are frequent violent floods, with water in the canyon rising up to 15-20 m, and flooding in the plains. The average flow of water at its mouth is approximately 700 cu m per sec, with a maximum of over 15,000 cu m per sec. The Douro is navigable for 200 km above its mouth. There is a reservoir and hydroelectric power station. The most important granaries of Spain are in the valleys of the Douro and Pisuerga. The Spanish cities Soria and Aranda de Duero and the Portuguese cities Pezo da Regua and Porto are situated on the Douro.