Erosion is one of environmental problems that most affect drylands in the world. In the Brazilian semi-arid, several areas present severe erosive processes, associated with desertification. Our objective is to analyze erosive processes in areas susceptible to desertification in the Brazilian semi-arid region in detail scales. For this purpose, we studied an experimental watershed of 2.9 km2 located in the Cabrobó Desertification Nucleus, state of Pernambuco. We used LiDAR images from 2016 year to 1:5000 scale analysis and UAV images from 2022 year to 1:500 scale analysis. In 2016, we identified 600 erosive incisions, between rills and gullies, with a total length of 41.6 km. Rill and gullies were connected in pronounced erosion networks associated exposed soils and grassland. From UAV 2022 images in critical sectors, we verified that the development of furrows and rills is delayed where biocrusts exist. In contrast, rills and gullies are well developed where there are saline crusts. In these sectors, the soils were completely removed, leaving only small residual structures. Although the real causes of desertification in this watershed are not yet known, we believe that erosion is related to complex, natural and anthropogenic factors. Thus, we consider that the methodology used can guide actions for the preservation and recovery of desertified areas with advanced processes of erosion.
Prof. Kleber Lima
Erosion Analysis in a Watershed Susceptible to Desertification in the Brazilian Semiarid
University of Pernambuco – Brazil