Estimativa da perda de solo na bacia hidrográfica do Paraná III: influência de diferentes cenários de conservação do solo

Abstract

Soil erosion is a natural process that affects rural and urban areas, and it can be intensified by human actions. Rainfall is one of the main factors, influencing soil disaggregation and particle transport. Estimating areas susceptible to water erosion is crucial for planning conservation practices, especially in agricultural regions. This study aimed to estimate soil loss in the Paraná III Watershed (BP3), comparing different scenarios for the conservation practices factor. The methodology involved estimating soil loss based on the Universal Soil Loss Equation (USLE), using QGIS software (version 3.28) to map the factors and create thematic maps. Data were collected on rainfall erosivity, soil erodibility, topographic factor, land use and management/cover, and conservation practices, with simulations of different scenarios for the conservation practices factor (0.3, 0.5, 0.7, and 1.0). The results of the different scenarios were reclassified into eight ranges, varying from 0 to >100 t.ha⁻¹.year⁻¹. The study highlighted that the Eastern and Southern regions of the BP3 Watershed showed the highest rates of increased soil loss as higher values were assigned to the conservation practices factor, with some points recording losses greater than 100 t.ha⁻¹.year⁻¹. The results confirm the need for proper management, even in soils such as Red Latosols and Nitisols, which, although suitable for agriculture, require conservation practices such as terracing to prevent degradation, especially on sloping terrain.