3.2 The Ebro River Basin
The Ebro river basin (Chapters 4, 5, and 6, Section 3) is the biggest catchment of the Iberian Peninsula flowing west to east, coursing into the Mediterranean (Figure 6). It is more than 85,000 km 2 wide and exposed to quite variable climates due to its size, wherein the west rainfall is heavier and flows are higher (Barceló et al. 2011) . Orography does also vary. The southern riverbank is relatively low in altitude in relation to the northern. The latter is mostly located on the Basque-Cantabrian mountains and the Pyrenees. The eastern river side passes the lower Catalan coastal mountain ridge. Figure 6 Subdivisions of the Ebro river Basin into Ecoregions. Points = exemplary diatom sampling in 2013. The Ebro river basin is conformed by 702 rivers and tributaries that conform this basin with a combined length of approximately 12,00 km [www.chebro.es]. Natural rivers predominate, with 70 very modified rivers and two “artificial” ones. There are 102 lakes in...