Key Concepts of Spanish Hydrology and Water Resources
Key Terms in Spanish Hydrology
Albufera: A coastal wetland separated from the sea by a string of sandbars (restingas) and connected only by a narrow passage. It is a typical coastal formation on the Mediterranean coast, such as the Albuferas of Valencia, Mallorca, and Menorca.
Aquifer: An accumulation of groundwater. It is formed when water from precipitation infiltrates the ground until it reaches an impermeable stratum where it accumulates. In Spain, these can reach levels of 400 in some months and are used for agricultural, industrial, and urban purposes.
Relative Flow: The relationship between the average annual flow of a river basin and its surface area, expressed in l/seg/km². In Spain, the rivers with the highest relative flow are found in the Cantabrian region.
Endorheism: A runoff pattern that occurs when watercourses do not flow into the sea but instead drain into inland lakes, ponds, or aquifers. In Spain, examples can be found in the interior basins and the Ebro Valley.
Drought (Low Flow): A period when rivers experience their lowest flow levels. In Spain, these low-flow periods (estiatges) are especially pronounced in eastern and southern rivers.
Salinization of Aquifers: An environmental problem caused by the overexploitation of coastal aquifers. As the water level drops, saltwater intrusion occurs, increasing the proportion of salt. This is common in the coastal aquifers of the mainland and the Balearic Islands.
Hydrographic Networks and Water Management
Exorheism: A type of hydrographic network where runoff water from the basin drains into the sea. In Spain, this is most intense in the Northern basins, the Duero, Tagus, and Ebro.
Water Resources: The quantity of available surface and groundwater in a specific space. In Spain, there are large differences in water availability across both time and space.
Flash Flood (Revinguda): A strong increase in river flow usually caused by torrential rains, sometimes with catastrophic results. In Spain, this phenomenon is usually associated with the cold drop (gota fría).
Torrent: An intermittent watercourse that only flows torrentially when it rains, while the rest of its bed or walkway remains dry. This is characteristic of the eastern zone, the Balearic Islands, and the Canary Islands.
Hydrographic Slope: A group of basins whose waters discharge into the same sea. In Spain, there are three main areas: the Cantabrian, Atlantic, and Mediterranean slopes.