Comprehensive Guide to Spanish Geography: Soil, Water, and Environmental Challenges
Item 3 (D): Soil
Soil
The superficial layer of the Earth’s crust. It consists of elements, liquids, gases, and solids.
Horizons
Soil layers that form the soil as a result of their evolution. Each horizon has its own physical, chemical, and biological characteristics.
Leaching
Process by which rainwater washes away substances to lower layers.
Soil Profile
This consists of all the soil horizons.
Pedogenesis
The science that studies the origin and evolution of the soil.
Brown Land
Located in oceanic climates. These are evolved soils, rich in humus.
Rankers
Suited to pasture and forest. They are less evolved and are found in sloping areas with significant erosion.
Vertisols
Located in areas such as Andalusia. These soils are very fertile and originate from clay.
Red Soil
Limestone soils suitable for tree crops and pastures. They are located in Mediterranean climates.
Bedrock
The substrate from which the soil forms. An example is granite.
Zonal Soils
Their origin is linked to the climate of the area.
Azonal Soils
They lack a concrete definition.
Intrazonal Soils
They have their own characteristics and are well defined. For example, Rankers.
Item 4: Water
Peninsular River Basins
Territory whose waters discharge to a main river and its tributaries. The main rivers are the Miño, Duero, Tagus, Guadiana, Guadalquivir, Ebro, Júcar, and Segura. The rivers and their tributaries pour water into a catchment basin: Atlantic, Mediterranean, and Cantabrian.
Atlantic Coast
Rivers are long and irregular, with high water in spring and autumn and drought in summer.
Mediterranean Coast
Except for the Ebro, rivers are short and irregular. Frequent floods and high water in autumn.
Cantabrian Coast
Rivers are short and regular.
Torrents
Intermittent courses of rivers that carry water only when it rains. In the Canary and Balearic Islands, there are only spring-fed brooks.
Lakes, Wetlands, and Aquifers
Lakes
These are water bodies that accumulate water and reach some depth. They may be:
- Endogenous: Their origin lies in the Earth’s internal forces and may be tectonic or volcanic.
- Exogenous: Their origin is in ice, rain, or wind. They can be of 3 types:
- Glacial lakes: Lakes of valley moraines, circus, etc. There are also the lakes of farms and coastal lakes and lagoons that are separated from the sea by a coastal ridge.
- Karst: An example is the Channel. They are formed by the dissolution of limestone.
- Arreicos: An example is the Tablas de Daimiel. They occur in arid areas and are very shallow due to evaporation.
Wetlands
Extensions of land covered by shallow water. Peatlands are areas with much vegetation that becomes flooded and incorporated into the soil as peat.
Aquifers
Underground water reservoirs formed by the infiltration of rainwater. They have the following characteristics: lack of harmful elements, stable temperature, and can be used for irrigation during periods of drought. In the Iberian Peninsula, there are aquifers located at the foot of the mountains or in the depressions of the rivers. They can release water into rivers, streams, or the sea.
Water Management
There is regular infrastructure and better water quality in rivers and other water resources.
- To regulate rivers:
- Reservoirs (expanses of water stored in dams)
- Channels (Waterways to distribute water)
- Transfers (To transfer water to water-deficient basins)
- To manage other water resources (lakes, marshes, etc.):
- Desalination
- Hydroelectric dams
To improve the quality of water, there are treatment plants (for consumption) and water purification plants (which treat wastewater to prevent contamination).
Hydrologic Policies: The Water Balance
Relationship between the existing water resources and the consumption of these resources. Spain has a problem of generating an annual deficit.
- The available water comes from rivers.
- More demand in the Mediterranean area where water resources are scarce.
- The network of dams in Spain is insufficient.
- Annual losses due to inadequate irrigation and leaks in agricultural and urban infrastructure.
Uses of Water Resources
Water consumption in Spain has increased with economic development. Agricultural use for irrigation accounts for 80%, while industry accounts for 6.4%. High domestic consumption creates high urban demand. The National Hydrological Plan (NHP) manages the regional imbalance in water resources. There are 4 goals to ensure quality and water supply for the better:
- Distributing resources across regions for development.
- Rationalizing the use and policies, promoting savings, and penalizing misuse.
European Policy
The European Union sets European guidelines for water policy, including the Water Framework Directive (WFD). Its objectives are:
- Sustainable, fair, and responsible water use and consumption.
- Protection from risks to the aquatic environment.
Item 5: Environmental Challenges
Air Pollution
- Acid rain: Rainfall with higher acidity than usual.
- Decrease of the ozone layer: The ozone layer filters ultraviolet radiation. Its depletion causes disruptions to plants and animals and can cause cancer and cataracts in humans.
- Greenhouse effect: Caused by gases in the atmosphere that trap radiation, preventing it from escaping into space. This can cause severe droughts, heavy flooding, etc.
- Smog, dust, and pollution: Excessive use of automobiles and industrial activity generate waste that accumulates in major cities, causing health problems and affecting plants.
- Noise: Noise pollution deteriorates environmental quality and causes physical and psychological damage.
Deforestation
Destruction of vegetation cover.
- Forest fires (96% caused by humans)
- Land requirement for agriculture, livestock, cities, and industry
Pollution, Desertification, and Soil Erosion
- Soil contamination: Caused by industrial and municipal discharges or by overuse of fertilizers.
- Soil erosion: Loss of topsoil caused by human action, deforestation, and inappropriate overuse of agriculture and livestock.
- Desertification: Loss of fertile topsoil (Guadalquivir Valley + Southeast Spain).
Overexploitation and Pollution of Water
- Overexploitation: High consumption of water in agriculture, industry, and cities. This can lead to the depletion of aquifers.
- Pollution: Contamination of water resources by human activities.
Urban Solid Waste (RSU)
High levels of pollution and non-biodegradable waste.
- Legal landfills: They alter the landscape and pollute the soil by the emission of gases.
- Illegal landfills: They can contaminate any area.