Spain’s Water Diversity: Influencing Factors and Geographical Analysis
Diversity Strategy and Spain’s Biogeographical Influence Factors
Factors influencing Spain’s water diversity are:
– The weather: River, lake, and aquifer water originates from precipitation. A sharp contrast exists between wet and dry Spain.
– Relief and topography: These influence basin organization, erosive capacity, and the formation of lakes and aquifers.
– Lithology: Rock type and characteristics determine permeable (filtered water) and impermeable rocks (favoring runoff).
– Vegetation: This retains moisture and prevents radiation.
– Human impact: Water consumption for drinking and irrigation, and the construction of reservoirs and dams, significantly impact water resources.
Spanish Rivers
A river is a natural, continuous flow of water, more or less abundant, flowing into another river, lake, or sea.
Drought is when a water stream reaches its lowest flow.
A flood is a moment of maximum river flow, often used to describe abnormal increases with catastrophic effects.Factors Affecting Peninsular Rivers
Factors influencing peninsular rivers are:
– Weather: Primarily rainfall, determining river flow (water volume per second) and regime (seasonal flow variations). We distinguish between nival, pluvial, and mixed regimes.
• Nival rivers: Originate in mountains. Maximum flow occurs in spring/summer; minimum in winter (snowmelt).
• Pluvial rivers: Originate from rainfall; maximum and minimum flow depend on the area.
• Mixed rivers: Two types: nivo-pluvial (main water supply from snow) and pluvio-nival (main contribution from rainwater).
– Relief and topography: Determine hydrographic basin and watershed organization, slope, river erosion, and ease of waterworks construction.
• A river basin is the territory whose waters flow into the main river and its tributaries. Rivers create channels within watersheds.
• Watershed management involves basins whose waters flow into the sea. 69% of peninsular rivers flow into the Atlantic/Cantabrian zone; 31% into the Mediterranean, due to the westward tilt of the Iberian Peninsula.
– Slope and erosion: Higher rivers have steeper terrain.
– Hydraulic works: Favored by steep topography, but high construction costs are a factor.
Lakes
Lakes are masses of fresh or saltwater accumulated in depressed areas. Spain has 2474 lakes, mostly small and seasonal, with short lifespans due to human impact.
Two main types of lakes exist:
– Endogenous lakes: Originate from within the Earth. These include tectonic lakes (formed by folds or faults) and volcanic lakes (formed in ancient volcano craters).
– Exogenous lakes: Caused by external forces (water, ice, wind). Five types exist:
• Glacial lakes: Formed by basin excavation.
• Karst lakes: Originate from limestone or gypsum dissolution.
• Arreic lakes: Formed by water accumulation without reaching the sea.
• Wind lakes: Formed by wind action.
• Coastal or lagoon lakes: Saltwater lakes separated by barrier islands.
Wetlands
Wetlands are land areas covered by shallow water, including lakes, marshes, lagoons, and deltas. They are biologically important for the plant and animal species inhabiting them, representing a transition between land and water.
Aquifers
Aquifers are underground water-bearing layers that seep until encountering an impermeable layer. Water may reach the sea via rivers, streams, or directly. Aquifer water is potable and used for irrigation. Over-extraction and pollution are major problems.
The Iberian Peninsula has over 400 aquifers, located in tertiary depressions (Duero, Tajo), near rivers (riverbanks), and in wet mountain headwaters (Douro, Tagus).
Vegetation Formations
Plant life in an area is divided into floral kingdoms. The Iberian Peninsula belongs to the Holarctic kingdom, with three floral regions: the Boreoalpine region (Pyrenees, Cantabrian Mountains), the Siberian region (northern peninsula, Iberian and Central Systems), and the Mediterranean region (rest of the Peninsula). The Canary Islands belong to the Macaronesian region.