Desertification: what it is, causes and consequences

Let’s start by clarifying what desertification is and what it consists of . It is the natural phenomenon as a consequence of soil degradation , which favors, over thousands of years, the appearance of desert climatic, morphological and environmental conditions.

This ecological process contributes to the aridification of originally fertile territories , higher rates of soil erosion, the deterioration of vegetation and a decrease in edaphic humidity, without such changes being induced by human activity.

An example of desertification is the Sahara which, according to cave paintings 10,000 years ago, had a more humid climate; in contrast to the desert conditions that characterize it today.

When we ask ourselves how soil desertification occurs , we must bear in mind that it can be triggered by multiple natural climatic, astronomical, geomorphological and dynamic factors.

• On the one hand, the weather plays a decisive role. In this context, the irregular nature of rainfall ( droughts or torrential rains), strong gusts of wind, frost, aridity and thermic climate (which favor salinization processes and the rapid removal of organic matter from the soil ), are capable of shaping the relief and accelerating soil degradation .
• On an astronomical level , the intensification of climatic changes (for example, of the seasons) in certain areas, caused by the Milankovitch cycles, also contributes to desertification processes.
• On the other hand, geomorphological factors , related to orogeny and lithology, which conditions resistance to erosion and desertification.
• Finally, dynamic factors , such as erosion or other physical-chemical processes, associated with the biological activity of the planet, wear down and destroy the soil, feeding the desertification of the territory. Here you can learn much more about the different types of erosion .

Although the desertification process is conceptually different from that of desertification, as we will detail below, it could be said that similar consequences derive from both phenomena. The consequences of desertification include the following:

• The lands become more vulnerable to erosion processes, favored by the loss and deterioration of the vegetation cover.
• Soils lose their physicochemical and mineralogical properties, reducing their functionality and productive capacity.
• All this affects the development of agricultural and livestock activities and, therefore, the well-being, work and the economy of those who dedicate themselves to it or live in areas affected by such phenomena. As a result, the emergence of environmental refugees takes place, who are people in a situation of abandonment of their homes, due to the costs that result from the desertification and desertification of the territory.

The term desertification , coined by André Aubréville in the middle of the last century, emerged in order to characterize the processes of land and soil degradation in the Sahel region (Africa). Later, the UNCED (1994) establishes that desertification is the degradation of land in arid areas, semi-arid areas and dry sub-humid areas , caused by various factors, such as human activities and climate variations, being ruled out of this process hyper-arid zones.

In this definition, the main difference between desertification and desertification can be identified and that is that the first of the phenomena can take place in a natural or anthropic way, while the origin of desertification is only natural . What does this imply? That the origin of desertification lies in the synergy of climatic and anthropic processes. Therefore, being the human being the main agent of land degradation, among the causes of desertification the following can be highlighted:

• Intensive agriculture, highlighting the strong influence of mechanization on the destruction and degradation of land. Bad agricultural practices such as land abandonment, the use of chemicals and monoculture.
• In arid regions, the pumping of groundwater for agriculture favors the salification (by evapotranspiration) of the aquifers and the soil, which causes a progressive and continuous erosion and degradation of the land. In the overexploitation of aquifers, it is important to highlight the “qanats” which are underground channels, used for water intake, which connect the entire Mediterranean, favoring desertification processes.
• Deforestation , mining and overgrazing.
• Poor and poor irrigation management. For example, the use of low-quality water for irrigation; the construction and modification of canals and channels.
• Tourism is an indirect cause as it implies greater urbanization of the land and other infrastructures (such as roads), greater demographic pressure on ecosystems and the intensification of extractive activities to meet the needs of the population.
• Forest fires , increasingly recurrent, increase soil degradation processes.

Given the importance of desertification processes, which affect our health and that of our ecosystems, the World Day to Combat Desertification and Drought is celebrated on June 17 in order to raise awareness about the importance of combating this problem of character anthropic.

We recommend you learn more by reading this other article about the Causes of desertification and its consequences .

Currently, given the temporal extension of desertification processes, it is sometimes difficult to differentiate whether the changes that take place in terrestrial ecosystems towards more desert conditions are of a natural or anthropic nature. That is why, normally, we speak of territories affected by desertification processes .

In this sense, Latin America and sub-Saharan Africa stand out as one of the areas most affected by land degradation.

The Mediterranean is also an example of soil degradation, highlighting in particular the progress that this phenomenon takes in the cities of Alicante, Murcia and Almería . In these areas, the orchard area is significantly degraded and largely destroyed, as a consequence of indiscriminate and poorly planned urbanization. In fact, beyond the Mediterranean region, Spain presents arid, semi-arid and dry sub-humid natural climatic conditions in two thirds of its territory, which makes it susceptible to desertification and desertification.