The Influence of Nature on Human Activity in Spain

Posted on Nov 4, 2024 in Geology

1 The Major Natural Landscapes of Spain

The environment’s diverse elements interact and create distinct biogeographical regions or landscapes. These areas vary in size and possess unique physical characteristics like relief, climate, vegetation, and water resources. Spain’s major landscapes include:

1.1 Humid Spain

Located in northern Spain, along the Cantabrian coast and in Galicia, Humid Spain experiences an oceanic climate. This climate features consistent and abundant rainfall throughout the year (over 800 mm annually) and mild temperatures with minimal thermal amplitude due to the sea’s influence.

The characteristic vegetation is deciduous forest, primarily beech and oak, accompanied by heath shrubs like heather, gorse, and broom, and abundant meadows.

The rivers, mainly originating on the Cantabrian side, are plentiful, regular, and short, as they are born in mountains near the coast. They are well-suited for waterworks.

Predominant soils include brown earth, a well-developed soil rich in humus and slightly acidic. With favorable topography, it is suitable for cultivation, while slopes are good for pasture. Ranker, an undeveloped soil found on slopes and prone to erosion, is also present. It is only suitable for forest and grass.

1.2 Mediterranean Spain

Located in the mainland south of Humid Spain, including the Balearic Islands, Ceuta, and Melilla, Mediterranean Spain has a Mediterranean climate. Rainfall is low (less than 800 mm annually), with the Ebro Valley and southeastern areas receiving even less than 300 mm. Coastal temperatures are mild with a low temperature range. Inland areas experience a continental climate with high temperature amplitudes.

The predominant vegetation is evergreen forest, mainly oak and cork oak, along with maquis (dense thickets of tall shrubs like jara and mastic), garrigue (dense thickets of low shrubs like thyme and rosemary), and steppe vegetation (discontinuous thorny shrubs like palmetto and espartal).

Rivers on the Atlantic slopes are long and experience summer droughts, while those on the Mediterranean side are short (except for the Ebro), irregular, and have pronounced summer droughts.

Soils with a clayey horizon include:

a) On siliceous rocky areas, the most characteristic is the southern brown earth, a poor soil with little humus, used for meadows and pastures.
b) On limestone areas, the Mediterranean red soil (terra rossa) is prominent. It is nutrient-rich and dominates on slopes or river meadows, supporting marginal crops like almond and olive.
c) On clay areas, vertisols or black soils, the most fertile soils in Spain, are found.
d) In the arid Mediterranean area, steppe soils depend largely on the bedrock and are therefore “geological.” The most characteristic is the gray serosem or subdesert soil found in the Ebro valley, which is very poor in humus.

1.3 Mountain Spain

Located in territories above 1000 meters, Mountain Spain has a climate characterized by annual rainfall exceeding 1000 mm and average annual temperatures below 10°C, with cool summers and cold winters (including a month with average temperatures near 0°C). Snow plays a significant role in this landscape.

Vegetation is arranged in staggered floors:

a) In the Pyrenees, the subalpine (conifers), alpine (grasslands), and nival (rock-dwelling plants or bare rock) zones are prominent.
b) Other mountains lack the subalpine coniferous zone. Only the typical forest zone and, at a higher elevation, scrub and grassland are present.

Mountain streams have their maximum discharge in spring due to snowmelt and their minimum in winter when water is retained as snow. High mountain rivers always have a nival regime with maximum flow in spring. In the mountain environment, the regime can be pluvio-nival or nivo-pluvial, with a secondary maximum coinciding with autumn rains.

Soils are poorly developed due to strong slopes that cause erosion. Rankers are prominent, along with southern brown earth on siliceous rocks and brown rendzinas on limestone.

1.4 The Canary Islands

Located in the Atlantic Ocean, off the northwest coast of Africa, the Canary Islands have a steppe or desert climate in the lowlands. Rainfall is very low and erratic on the coast (less than 300 mm annually for a steppe climate and less than 150 mm for a desert climate). It increases significantly with altitude and can reach 1000 mm. Temperatures are warm year-round (no month with an average temperature below 17°C) and have a very low thermal amplitude (less than 8°C).

The original vegetation has Mediterranean, African, and Atlantic influences. Endemic and relict species are of great importance. In the mountainous relief, vegetation is organized into floors: bush, palm tree-dragon tree-juniper, laurel-fayal-heath, pine, and Canary Island scrub, which has a rich flora.

Water resources are very scarce and erratic. They appear superficially as streams and rivers. Aquifers predominate.

Soils are volcanic, often forming “badlands.” They are poorly developed, and many are unproductive.

2 The Influence of Nature on Human Activity

The natural environment affects human activity in two ways: positively, by providing resources, and negatively, through the risks it poses.

2.1 The Natural Environment and Resources

The natural environment provides resources to humans, which are elements used directly or indirectly to satisfy basic needs and achieve economic benefit. The existence of these natural resources can contribute to socioeconomic development in an area, but today this is increasingly dependent on extranatural factors, such as:

a) Relief:

Influences settlements, which seek the most favorable sites (valleys, hills…).
Affects farming, often unfavorably due to steep slopes.
Provides mineral and energy resources.
Impacts communication, as steep slopes necessitate the construction of tunnels and viaducts.
The peculiarities of the terrain can be a tourist attraction.
Coastal relief is not conducive to farming but can be beneficial for tourism.

b) Climate:

The atmosphere provides essential gases for life.
Influences population distribution and habitat, as people avoid areas with adverse climatic conditions.
Exerts a significant influence on agriculture.
Provides various sources of renewable and clean energy.
Is also involved in various activities in the tertiary sector.

c) Vegetation:

Is essential for life.
Provides food, raw materials, and energy sources.
Is a resource for leisure and recreation.
Contributes to the protection and improvement of environmental quality.

d) Water:

Is an essential resource used in many human activities.
Used for agricultural irrigation to improve farm yields.
Used for energy production from hydropower.
Used for urban consumption in homes, tourism, gardens, etc.
Used for the evacuation of waste from agriculture, livestock, and industrial systems.
Supports activities like fishing, navigation, and various recreational uses (swimming, golf, etc.).

e) Water Balance:

Lists the available water resources and their uses.
In Spain, the balance is positive, but several issues cause only a fraction of the resources to be usable.
Water availability mainly comes from rivers, with some basins having a surplus (north, Duero, Tagus, Ebro) and others a deficit (other Mediterranean basins).
Demand is concentrated in the areas of greatest economic and demographic dynamism, the Mediterranean area, where resources are scarce.
The existing network of dams is insufficient to meet rising demand.
There are significant annual water losses due to the use of inadequate irrigation systems.

These problems cause an annual deficit of around 3000-4000 cubic hectometers.

f) Water Policy:

Aims to regulate and manage water resources and alleviate related problems.
Regulation is carried out by the Water Law, which states that all surface water and the channels through which it circulates are public domain.
Resource management is through water policies that aim to increase resources, prevent flooding, and improve water quality.
Water policy instruments include:
- River basin management plans: determine the necessary work in each basin.
- The National Hydrological Plan: coordinates the plans of the watersheds and indicates actions to regulate water resources in all of them.
- Hydraulic works: infrastructure created to regulate water resources and improve water quality. These include reservoirs, distribution channels, and diversions to regulate rivers; desalination plants to regulate other water resources like lakes, aquifers, and marine waters; and water treatment plants to improve water quality.

g) Soil:

Influences various aspects of human activity, such as agricultural production, livestock, and forestry. Each soil type, with its different texture and consistency, facilitates or hinders tillage and the mechanization of agricultural tasks.
Populations have traditionally preferred to occupy areas with fertile soils, which offer better food options.
Housing and infrastructure are affected when built on clay soils.

2.2 Natural Hazards

Natural hazards are environmental features that threaten human well-being or life due to their potential catastrophic consequences. The most frequent in Spain are:

a) Geological Risks:

Earthquakes: Due to the Iberian Peninsula’s location at the edge of the African and Eurasian plates.
Volcanic eruptions: Primarily affecting the Canary Islands.
Landslides: Rapid movements of large masses of soil or rocks caused by a trigger. They fall into two types: landslides, typical of humid climates, and rockfalls, which occur on slopes where rupture processes act on the upper part of the materials.

b) Climate-Induced Risks:

Floods or flash floods: Caused by intense precipitation.
Droughts: Have a lower incidence than floods.
Hailstorms, cold or heat waves, storms: Occur less frequently.

Actions to mitigate these natural hazards include:

Constructing infrastructure to mitigate them, such as drains, planting trees, and water works.
Establishing forecasting and monitoring systems.
Implementing emergency actions (Civil Protection).
Setting standards and raising awareness.