Análise da relação entre a propensão à desertificação e o uso da terra no semiárido brasileiro

Abstract

In Brazil, desertification affects a large part of the semiarid region, which points to the need for greater attention to this problem, in order to combat or minimize its effects. Rural areas are the most impacted by desertification, mainly due to inadequate land exploitation practices. The seriousness of the problem makes the colloquy between scientific knowledge and stakeholders relevant and raises the question still unanswered: how do land use patterns contribute to the expansion of desertification in the Brazilian Semiarid? It is assumed that land use contributes to an increased propensity to desertification, combined with the vegetation, pedological and socioeconomic factors of this region. In view of this, the present study seeks to analyze the propensity to desertification based on land use in the Brazilian Semiarid Region. Specifically, the characterization of land use as a causative agent of desertification is made; the classification of municipalities according to the propensity to desertification according to land use; the characterization of soil and vegetation types from the propensity to desertification according to land use; and, finally, the analysis of the relationship between vulnerability to desertification, according to land use and the types of soil and vegetation. For that, secondary data were used referring to a sample of 976 municipalities in the semiarid region. The methods of analysis adopted involved; a) techniques of tabular and graphical analysis; b) construction of a Desertification Propensity Index based on land use indicators that are grouped in the dimensions of exploration practices and type of exploration; and c) inferential statistics techniques such as Analysis of Variance. The results showed that the main land uses in agricultural establishments are related to agricultural activities. Intensive land use is the factor that best explains the propensity for desertification in the region, which is heterogeneously distributed in space, although there is a greater vulnerability to the problem among the municipalities located in the central-northern portion of the SAB. The study showed that higher levels of desertification are present in establishments that have Chernossolos Rendzicos Órticos soil. In addition, most municipalities with soils such as Concrete Pletrossols, Dystrophic Heather Plintosols and Sodium Sodium Gleysols are also in the class with the highest propensity levels. Regarding vegetation, it was identified that the predominant vegetation in the SAB is divided into those that make up agrarian activities and the Savanna-Estépica Arborizada, although there is a mosaic with different types of vegetation. As a provisional answer to the question that instigated the research, it is assumed that the use of land may contribute to an increase in the propensity to desertification, combined with the pedological and vegetation aspects of this region.