Dinâmica Espaço-Temporal da Paisagem Semiárida no Município de Apodi/RN e seus Condicionantes Socioeconômicos e Ambientais

Abstract

Apodi, like many municipalities in the Northeast, underwent structural changes conducted by two main drivers: alternation of socioeconomic models and seasonal and prolonged periods of drought. Among the socioeconomic models, Apodi passed by large landowners, agrarian reform, expropriation of land for irrigated perimeters and installation of agribusiness companies. These conditions negatively impacted the vegetation cover, degrading the landscape and threatening the Lajedo de Soledade Archaeological Site (SALS) located in the middle of this landscape, an important cultural and environmental patrimony. In this context, the objective of this study was to analyze the spatio-temporal changes in the landscape around SALS and to infer about the influence of socioeconomic and environmental drivers. For this, a survey of the region's history, precipitation data, agricultural production of the main crops, and eight images captured by the TM and OLI sensors of the LANDSAT 5 and 8 satellites, between 1984 and 2018, were used. Precipitation data was modeled using the Standardized Precipitation Index (SPI). The images were classified using the SCP plugin (QGIS) and the quality was assessed using the Kappa Index. It was observed that there were three prolonged and extreme droughts events in the region: late 1980s and 1990s and between 2013 and 2017. The classification of the images indicated periods of dense vegetation reductions and exposed soil expansions, in the period of decay of cotton culture, and the reversal of these patterns after agrarian reform, with the establishment of family farming on an agroecological basis. This pattern was again reversed, with the lowest proportion of dense vegetation observed (5%) and and higher proportion of exposed soil (45%) observed in this landscape, during the period of installation of the irrigated perimeter for agribusiness. Thus, it was possible to infer that the alternation of socioeconomic models conditioned the spatio-temporal dynamics of the vegetation cover and was responsible for the environmental degradation conditions surrounding the SALS, these patterns being aggravated by the recurrence of periods of extreme and prolonged drought. During these periods, SALS was probably more vulnerable to the direct and indirect effects of anthropogenic activities common in this landscape.