Iberian Peninsula: Relief, Climate, and Rivers
Relief
The rocky Iberian Peninsula can be divided into three areas: siliceous, limestone, and clay.
The siliceous area consists of ancient Precambrian rocks, primarily located in the western peninsula (Galicia, Leon, Extremadura, and most of Portugal). Granite is the predominant rock. This area also includes remains of ancient massifs, such as in the Pyrenees, Iberian and Catalan Coastal Range, and the Penibetic system.
The limestone area consists of secondary sediments folded during the Tertiary. These lands form an inverted “z” shape, spanning the pre-Pyrenees, Cantabrian Mountains, Iberian System, Cordillera Costero-Catalana, and Cordillera Subbetica. Limestone gives rise to complex reliefs like sinkholes and dolines.
The clay area consists of less resistant sedimentary materials deposited in the late Tertiary and early Quaternary. It is located in the two sub-plateaus, the Ebro and Guadalquivir depressions, and the Mediterranean coast plains. Clays and loams dominate, leading to forms like gullies or badlands.
The Plateau is the core of the Iberian Peninsula, an elevated plain covering nearly 45% of the peninsula with an average altitude of 600 meters. It comprises remnants of the basement in two mountain ranges and several sedimentary basins:
- To the west, eroded Tertiary basement outcrops.
- The Central Cordillera and Montes de Toledo, formed in the Tertiary.
Mountain ridges of the plateau include the Massif Galaico-Leon, Cantabrian Mountains, Iberian System, and Sierra Morena.
The archipelago consists of the Balearic Islands (Mallorca, Menorca, Ibiza, Formentera, Cabrera) and the Canary Islands.
- Mallorca has the Sierra de Tramuntana, Sierra de Levante, and a central depression.
- Ibiza features small, low-lying mountain ranges.
- Menorca is tied to the Catalan Coastal Range.
The Canary Islands are volcanic, with Mount Teide on Tenerife as the main morphostructural element.
Peninsular coastline: 3,500 kilometers, mostly straight except for the Galician coast.
- The Atlantic coast includes the Cantabrian, Galician, and Andalusian coasts.
- The Mediterranean coasts include the Betis sector, Gulf of Valencia, and the Catalan coast.
Climate and Landscape Diversity
Factors Affecting Climate
Spain has diverse climates due to dynamic and geographic factors.
Dynamic factors include air masses: maritime tropical, continental tropical, maritime polar, arctic, and continental polar.
Geographic factors include latitude, situation, relief, and configuration.
Temperature
Spanish climates are temperate, with average temperatures varying across regions.
Climate Types
Oceanic climate: Northern Spain, abundant rainfall, mild temperatures.
Mediterranean climate: Most extensive, with subtypes: maritime, continental, and semiarid.
Mountain climate: Territories over 1,000 meters, high rainfall, low temperatures.
Canary Islands climate: Unique due to latitude, low rainfall, warm temperatures.
Vegetation
Mediterranean area: Evergreen forests and shrubs.
Siberian area: Deciduous trees.
Macaronesian area: Endemic species adapted to drought.
Spain in International Organizations
Spain’s international isolation ended with admission to the UN in 1955 and OECD in 1959. Spain joined the EEC in 1986.
Implications for Physical Geography
The Iberian Peninsula’s situation and position create diverse influences on climate and vegetation.
Spanish Rivers
Cantabrian Rivers
Short, regular rivers with abundant estuaries.
Galician Atlantic Slope Rivers
Suitable for hydroelectric energy production.
Plateau Rivers
Long rivers with summer minimums, including the Duero, Tagus, and Guadiana.
Mediterranean Rivers
Short, irregular rivers, often dry in summer.
River Regimes
Nival regime: Higher elevations, snowmelt peak.
Nivo-pluvial regime: Mountains of 2000-2500 meters, snowmelt and pluvial maxima.
Pluvio-nival regime: Altitudes from 1600 to 1800 meters, snow and storm influence.
Factors Affecting River Courses
Climatic factors, soil constitution, topography, and vegetation.