Pyrenees

Fig. 2.28 Partial map of Western Europe showing location of the Pyrenees, the Jura, and the Alps from which Pinus uncinata populations were sampled...

The Cantabrian Mountains and the Pyrenees in the North, the Iberian System in the South-East, and the Coastal Catalan mountains in the East are the natural limits of the Ebro River basin. Traditionally, the river source was supposed to be at Fontibre (name derived from Forties Iberis in latin, Springs of Iberia ) at 880 m.a.s.l., near Reinosa in Cantabria. Nowadays, the river source is placed at 1,980 m.a.s.l., the water coming from a source in Penalara (27 km upstream from Reinosa). The main river channel is 910 km in length, flows NW-SE, from the Cantabrian Mountains to the Mediterranean Sea, where it forms a delta. 

The river Ebro basin has a triangular shape, where the larger sides are the Iberian range and the Pyrenees, the two converging in the north-east (Fig. 1). In between, a depression increases in width from the west to the east. Just before the river mouth the Ebro crosses the Catalan Mountain Range. 

The topography of the Ebro River basin determines a Mediterranean climate with continental characteristics in most of the river basin as well as a semi-arid climate in the center of the depression. At the western extreme of the basin (Pyrenees and Iberian mountains), there is an oceanic climate. The central part of the basin is isolated from the oceanic influence because of the surrounding mountains. This results in the increase of the continentality of the climate and the drastic decrease of the rainfall. In the central part of the river basin (Zaragoza, Alcaniz, and Lleida urban areas), aridity is the main climatic characteristic. 

Jones SJ, Frostick LE, Astin TR (1999) Climatic and tectonic controls on fluvial incision and aggradation in the Spanish Pyrenees. J Geol Soc 156 761-769... 

Lopez-Moreno JI, Beniston M, Garcia-Ruiz JM (2008) Environmental change and water management in the Pyrenees Facts and future perspectives for Mediterranean mountains. Global Planet Change 61 300-312... 

Lopez-Moreno JI, Begueria S, Garcia-Ruiz JM (2002) Influence of the Yesa reservoir on floods of the Aragon River, central Spanish Pyrenees. Hydrol Earth Syst Sci... 

Garcia de Jalon D, Montes C, Barcelo E, Casado C, Menes F (1988) Effects of hydroelectric scheme on fluvial ecosystems within the Spanish Pyrenees. Regul Rivers Res Manage 2 479 191... 

Goma J, Rimet F, Cambra J, Hoffmann L, Ector L (2005) Diatom communities and water quality assessment in mountain rivers of the upper Segre basin (La Cerdanya, Oriental Pyrenees). Hydrobiologia 551 209-225... 

The Ebro river catchment covers 85,534 km2 and flows from an altitude of 3,404 m in the Pyrenees in Cantabria (NE Spain) southeast to the Mediterranean Sea (Fig. 1), where it has an ecologically and agriculturally important delta that covers more than 150 km2 [5]. 

Fourcade, S. Allegre, C. J. (1981). Trace-element behavior in granite genesis A case study. The calc-alkaline plutonic association from the Querigut complex (Pyrenees, France). Contrib. Mineral. Petrol., 76, 177-95. 

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