Vulnerabilidade natural à perda de solo no município de Anastácio/MS: subsídio para o zoneamento ecológico-econômico

Abstract

The natural vulnerability analysis to soil erosion enables the identification of stable and vulnerable areas within a spatial framework. Such studies support the Ecological-Economic Zoning, thus contributing to territorial management to maintain economic and social growth without causing environmental modifications. Therefore, the present research aimed to Identify the Natural Vulnerability to Soil Loss in the municipality of Anastácio/MS, providing applications for Ecological-Economic Zoning. The methodology proposed by Crepani et al. (2001) was applied as a tool to support Ecological-Economic Zoning, based on the concept of Tricart's Ecodynamics (1977), aiming to analyze the relationships between pedogenesis and morphogenesis to establish the vulnerability classes of the UTBs and, through map algebra, establish the natural vulnerability of the most stable and vulnerable areas to erosive processes. Thus, the Climate, Vegetation, Soils, Geology, and Geomorphology data of the municipality of Anastácio were organized and, through an environment in GIS in the QGIS 3.10 software, the techniques of treatment, analysis, and weighting of the values of the found classes were applied. Subsequently, land use and cover information was acquired through the MapBiomas project to analyze use incompatibilities. The analysis of natural vulnerability to soil loss in the municipality of Anastácio revealed that the study area has 87% of the area classified as Moderately Stable/Vulnerable, identified mainly by the presence of pasture, where there was removal of native vegetation for livestock implementation. The Moderately Stable class was also identified, representing 10% of the study area. It is found in areas with native vegetation and rocks with high cohesion, such as Basalt from the Serra Geral Formation. An important point to be highlighted is the presence of vegetation near steep areas, considered natural barriers to advancing anthropic activities. The Moderately Vulnerable class, present in 3% of the study area, is defined by the presence of rocks with a low degree of cohesion, such as sandstones and unconsolidated materials, shallow soils, where morphogenesis prevails, such as Gleisols, Plinthosols, and Neosols, and areas with high slope, in addition to the presence of pasture. The smallest class identified was Stable, comprising 01% of the study area and around the Moderately Stable class. From the analysis of the data on natural vulnerability to soil loss and the land use and cover maps, the strong influence of pasture was noted, as well as the need for implementation of adequate soil management to prevent the emergence of erosive features, such as the implementation of Level Curves and Terracing, in addition to the need to maintain vegetation near rivers.