WHAT ARE GEOGRAPHICAL PHENOMENA? - GEOGRAPHY - 2025

The geographical phenomena are observable and those drastic changes taking place in nature. They can occur abruptly and are capable of transforming the environment, in such a way that, after these phenomena occur, a new reality arises.

Geographical phenomena are complemented by geographical facts, which refer to elements that are stable and whose variations are perceived over longer periods.

So in nature you start from a geographical fact. Then a phenomenon is usually generated that generates an abrupt variation in the environment, and the new reality that is generated later becomes a new geographical fact.

Geographic phenomena can be classified according to the elements from which they are produced. This classification includes three types: physical, biological and human.

Types and characteristics of geographical phenomena

- Physical geographical phenomena

Physical geographical phenomena refer to those that are generated without involving any living organism. These drastic changes are normally produced as a consequence of climatic, physical or chemical elements, among others, generated naturally.

Within the physical geographical changes can be found hurricanes, cyclones, torrential rains and earthquakes, among others. The physical geographical changes that are generated are capable of transforming the landscape and generating a new reality.

Some examples of physical geographic changes can be:

River overflow

The Amur River rises in northwestern Mongolia in the Khentii Mountains. Photo: Lucas Henrique Guerra Santos

A river can overflow as a consequence of different natural causes. Some of the possible causes may be the following:

• Following heavy and sustained rains in a short time
• consistent rains for a long time
• Canal obstruction due to landslides
• Sea level rise
• Thaw

When a river overflows, it can create lasting changes in the landscape. The river may permanently expand its channel, flood surrounding plant species, and if human communities are nearby, it may obliterate houses, buildings, roads, and other constructions.

Volcano eruption

Sakurajima, one of the most active volcanoes in the world.

The eruption of a volcano is generated by the movement of tectonic plates, or by the accumulation of pressure of magma (molten rock that exists in the depths).

In either case, the eruption of a volcano is considered a physical geographic phenomenon because it occurs without the intervention of living individuals.

When a volcano erupts, it can have definite consequences on its environment, including:

• The destruction of fauna as a result of lava
• Devastation of the flora by the action of the ash
• Generation of forest fires
• Even if the eruption is very large, it can increase the greenhouse effect as a consequence of the absorption of heat from the ash ejected out of the atmosphere.

- Biological geographical phenomena

Biological geographical phenomena are those that are generated by living beings, excluding humans.

Within this classification are the geographic variations produced by plants, animals, insects and microorganisms.

Some examples of biological geographic changes can be:

Deforestation by plague

Desertification and deforestation. Source: Frank Vassen from Brussels, Belgium

The appearance of pests can destroy large areas of flora. Pests can appear, for example, as a consequence of an imbalance in the fauna; If there are no natural predators, a species can become a pest.

Pests especially affect plants located in soils with few nutrients, and can result in the deforestation of entire regions and completely altering the environment.

Pests can also greatly reduce the number of animal organisms in an area.

Species extinction

It is possible for a species to disappear due to natural causes, without human intervention. For example as a result of physical phenomena, such as droughts, fires or floods, among others.

The extinction of a species can permanently alter the entire ecosystem of which it is a part. The cycles of nature can vary, as can the structure of food chains.

- Human geographical phenomena

These phenomena are among the most obvious and, in many cases, invasive that can be found on the planet. Human geographical phenomena are caused exclusively by the action of man in their environment.

Like physical and biological phenomena, human geographic phenomena alter the environment in a lasting way. As a result of these transformations, positive consequences can be generated and, in many cases, also negative ones.

Some examples of human geographic phenomena:

Road construction

As a result of the need to expand their communication channels, human beings have transformed their environment. This has involved the construction of highways and roads that openly intervene in the environment.

The construction of this type of structure has been beneficial for the development of the human race, allowing broadening the interaction between men and generating more effective communication.

However, in some cases the intervention has been detrimental to nature, because some ecosystems have been affected.

As a consequence of this type of construction, entire species of flora and fauna can disappear, or diversions of water courses can be generated, among other manifestations.

Dam construction

Itaipu Dam. Source: Herr stahlhoefer

Hydraulic dams are structures, made with walls and containment elements, whose main function is to store or divert the water from a river to fulfill different purposes.

Among the functions of a water dam are the regulation of the water supply in a particular region, the storage of water for irrigation or energy production.

When building a dam, humans intervene to a large extent in nature. These constructions generate positive consequences for human life, such as the production of renewable energy, the control of floods in certain areas and the fact of facilitating access to water for human consumption.

On the other hand, the construction of dams is considered a geographical phenomenon because it permanently transforms the environment:

• Generates stagnant waters, which can bring diseases
• Blocks the passage of different marine species, affecting migratory movements
• It promotes the extinction of entire colonies of organisms, which make life in rivers.

References

1. "Definition, application of geography and representations of the earth" in the National Institute of Statistics, Geography and Informatics. Retrieved on August 17, 2017 from the National Institute of Statistics, Geography and Informatics: inegi.org.mx.
2. Borrajo, J. "Environmental effects of road construction" (March 1999) in Carreteros. Retrieved on August 17, 2017 from Carreteros: carreteros.org.
3. Castro, G. "Impact and Consequences of Dams" (June 8, 2005) in Ecoportal. Retrieved on August 17, 2017 from Ecoportal: ecoportal.net.
4. Tablado, A. "Represa" in the National Council for Scientific and Technical Research. Retrieved on August 17, 2017 from the National Council for Scientific and Technical Research: mendoza-conicet.gob.ar.
5. Taylor, J. "What Causes a Volcanic Eruption?" in eHow in Spanish. Retrieved on August 17, 2017 from eHow in Spanish: ehowenespanol.com.
6. Martí, J. “Why do volcanic eruptions occur? Is it possible to predict them? " (August 5, 2011) in Public. Retrieved on August 17, 2017 from Public: publico.es.
7. Martínez, N. "Consequences of the eruption of volcanoes" in eHow in Spanish. Retrieved on August 17, 2017 from eHow in Spanish: ehowenespanol.com.