The dynamic of land cover and use and threats to geodiversity in the municipality of São Lourenço do Sul (Brazil)

Abstract

The respective study aims to analyze and understand the dynamics of land cover and land use, with regard to threats in places with high geodiversity indices in the municipality of São Lourenço do Sul, state of Rio Grande do Sul, Brazil. Initially, data on land cover and land use were obtained for the aforementioned spatial clipping in the years 1985, 1995, 2005, 2015, and 2020, originating from MapBiomas. Over the derived maps, the polygons that represent the areas with high geodiversity indices were superimposed, in order to enable the understanding of the threats that the spatial evolution of land uses triggered in these areas with higher spatial concentration of the abiotic elements of nature that composed the geodiversity index (geology, geomorphology, pedology and hydrography). The data obtained show a generalized decrease in the native cover of the pampa biome (grassland formation) with the expansion of areas surrounded by the cultivation of temporary crops, mainly soybean and forestry for the municipality of São Lourenço do Sul. In the polygons that represent the high geodiversity indexes, besides the general behavior of the coverings and uses identified for the municipality, there was the advance of tobacco farming in the highland region and the evolution of temporary crops (emphasis on irrigated rice) in the coastal plain areas. Such results allow us to understand the importance of monitoring and preserving the sites with high geodiversity indexes in the study area.