THE sandization consists of the process of formation of sandbanks in the soil, in a phenomenon equivalent to desertification, differing from this in that it manifests itself in areas with a humid and relatively rainy climate, in addition to being common in soils with a previously sandy composition.
O sanding process it is considered an environmental and a socio-spatial problem, as it is responsible for the devastation of conservation areas and for making the soils used for agriculture and cattle raising infertile. Thus, its causes and effects require an accurate and efficient diagnosis in order to avoid its extension to other areas.
The main causes of soil sandization they are of anthropic origin, such as the removal of vegetation cover and intensive activities of agriculture or livestock in places with sandy soils. With this, there is an impoverishment of the surface layer and greater exposure to washing caused by the runoff of rainwater (leaching), causing the accumulation of sediments in the form of sands.
Thus, to contain the progress of the sandization process, it is necessary to identify the areas whose soils are predisposed to this occurrence and to use them sparingly, taking measures to contain the erosion laminar. These measures include the preservation of vegetation and the adoption of cultivation techniques specifically aimed at this purpose, such as contour lines.
Most of the sediments responsible for the accumulation and formation of sands that make unproductive soils come from areas a little bit higher, which explains the fact that sanding is more common in regions that record the existence of unevenness in the forms of relief. In addition to rainwater, another important agent responsible for sanding is the wind, which also helps in the erosion process and involves wear, transport and sedimentary deposition.
As we've already mentioned, there is a substantial difference between sandization and desertification, whose conceptual merits are attributed to the Brazilian research geographer Dirce Maria Antunes Suertegaray. In his study of the process then considered as desertification in Rio Grande do Sul, she diagnosed that the dynamics of the phenomenon in question differed in that it occurred from the action water and wind, while in desertification the problem was the result of soil depletion and accentuated evaporation.
Therefore, the difference between sandization and desertification lies in the fact that the latter manifests itself in areas with an arid, semi-arid and subhumid, where average annual rainfall does not usually exceed 1400mm and evaporation is greater than the accumulation of water in the soil. In sanding, it is the opposite, as water precipitation is greater than evaporation and the problem occurs precisely by sedimentation caused by the action of water and wind, with the deposition of sediments in the form of sand on the ground.
In Brazil, the sanding is officially registered in the southern region of the country, while desertification occurs, to a greater degree, in the Northeast region, which has a drier climate in much of its area.
By Me. Rodolfo Alves Pena