Characterization of vulnerability to desertification by geotechnologies in the south of the state of Sergipe

Abstract

Erosive phenomena play an important role in the desertification process, progressively contributing to land degradation and the consequent change of landscapes, with water erosion being one of the most common factors in high-slope regions. In regions with low rainfall, desertification occurs due to the concentration of salts on the soil surface, aggravated by evapotranspiration and inadequate vegetation management. In this way, the work sought to classify some of the agents accelerating the process of soil impoverishment in an area that ranges from eastern Sergipe to the semi-arid region, in the hydrographic basins of the Real and Piauí rivers, with the aid of geoprocessing techniques for creating thematic maps from vector files, Digital Elevation Models (DEM) and Landsat-8 images. Although 39.33% of soils are highly susceptible to water erosion, with slopes between 20 and 45%, the presence of low levels of average precipitation, 46.63% of soils poor in drainage and high exposure of slopes to the sun (41.8% in the West) in periods of greater solar radiation, in addition to the presence of high human activity in sectors such as agroforestry and pastoral activities. A relationship was found between these conditions and the electrical conductivity of groundwater, increasing from east to west. Therefore, it was concluded that the set of factors analyzed tend towards the objective proposed by the work, with more in-depth studies being essential for the real estimation of environmental risks associated with the region's soils.