Modelagem da erosão hídrica do Estado do Ceará, Brasil

Abstract

In the State of Ceará, water erosion is a serious environmental problem, even in regions of the state with severe droughts and low rainfall. The irregular hydrological regime marked by high intensity rainfall combined with morphostructural and pedological characteristics and land use in the region has intensified the process of water erosion. In this scenario, estimating soil losses by modeling water erosion in the State of Ceará is an alternative to assist in proposing public policies aimed at preventing erosion and conserving soils. The hypothesis of this research is that in the Brazilian semi-arid region present in Ceará there are areas with high soil losses, even in the face of low rainfall. Ceará was chosen as the study area due to the scarcity of information on water erosion. To estimate soil losses, the Erosion Potential Method (EPM) was used with the aid of a Geographic Information System and remote sensing. The variables used in the EPM were defined based on climatic, pedological, topographic factors, land use and management, and erosive features. The estimated average soil loss was 9.7 Mg ha -1 year - 1 and the study showed that in 38% of the State of Ceará there was soil loss above the soil loss tolerance limits. These sites are located mainly in non-vegetated, crop and pasture areas. The research results are important to identify priority areas for the adoption of measures to mitigate erosion processes and for the elaboration of sustainable public policies for soil and water conservation.