We explain what erosion is and what this physical process consists of. Also, how wind erosion and water erosion are carried out.
What is erosion?
Erosion is the wear they exert along the weather the different physical processes of land surface Over the soils, rocks and materials that could exert resistance to them. The main erosive agents are wind, Water, ice and temperature changes.
Erosion is not equivalent to weathering, alteration or disintegration of rocks. For there to be erosion, a transport of matter or a movement of the same, whose repeated passage generates friction and wear on the materials, producing the relief, for example, of valleys, canyons, caverns, plateaus and other structures whose formation does not involve the hand of the man.
However, certain human activities can promote or even accelerate erosion. For example, logging for agricultural purposes removes the topsoil from the soil, leaving it uncovered to the action of rain or wind, which can eventually lead to infertility of the soil due to loss of nutrients.
In fact, under the right conditions, erosion can be an intense force in the desertification of soils, which would contribute to the expansion of 35% of the land area that is already considered desert.
On the other hand, the action of wind or water can produce interesting natural monuments: natural arches or peculiar rock formations, such as those that exist in the Salar de Uyuni, in Bolivia, or in the Valley of the Moon in San Juan, Argentina.
Eolic erosion
This is the name given to the erosion product of the constant action of the wind over the years, transporting particles tiny sand or rock that, in constant friction against soils, stones and moutains, they are reducing their outer layers, carving them.
Wind erosion in desert areas is responsible for shaping sand dunes, displacing them, or forming the deserts made of stone, called "erg". In humid areas, on the other hand, it usually produces flat or slightly undulating reliefs, due to the transport of much finer materials, such as sedimentary clay deposits.
Water erosion
Water erosion is due to the action of multiple forms of water, from rain, rivers, seas and their phase changes according to the climatic seasons. Thus, the constant pounding of the waves on the sand on the shore reduces and rounds off the pebbles that make up the sand, giving them their characteristic fineness and roundness, which is also the case with river stones.
On the other hand, the larger rocks resist the impact of the water without moving, but gradually losing particles of their outer layer, thus acquiring the roundness and smoothness that usually characterize them, or the holes and craters into which the drops of water fall incessantly .
The cliffs, likewise, or tidal flats, are the product of the action of the sea over the centuries, just as it happens with the riverbeds, in which the soil matter is eroded and sedimented at the same time.
The same occurs in glacial regions, in which the movement of ice, or even its constant formation and melting, have an impact on the surrounding materials, also causing their wear.